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1

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

DOE Patents (OSTI)

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.

Norem, James H.; Pellin, Michael J.

2013-06-11T23:59:59.000Z

2

Nanofabricated Superconducting RF Composites: The surface composition...  

NLE Websites -- All DOE Office Websites (Extended Search)

January 29, 2008 Conformal Coating Removes Field Induced Breakdown Figure 3: Scanning Electron Microscope images of nearly atomically-sharp tips, before and after coating with...

3

Pushing the Limits of RF Superconductivity Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Presentations Workshop Proceedings Suggested Reading Material on RF Superconductivity Workshop Dinner Accommodations Ground Transportation Access to...

4

Degreasing and cleaning superconducting RF Niobium cavities  

Science Conference Proceedings (OSTI)

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.

Rauchmiller, Michael; Kellett, Ron; /Fermilab

2011-09-01T23:59:59.000Z

5

Eccentric superconducting RF cavity separator structure  

DOE Patents (OSTI)

Accelerator apparatus having an eccentric-shaped, iris-loaded deflecting cavity for an rf separator for a high energy high momentum, charged particle accelerator beam. In one embodiment, the deflector is superconducting, and the apparatus of this invention provides simplified machining and electron beam welding techniques. Model tests have shown that the electrical characteristics provide the desired mode splitting without adverse effects.

Aggus, John R. (Shoreham, NY); Giordano, Salvatore T. (Port Jefferson, NY); Halama, Henry J. (Shoreham, NY)

1976-01-01T23:59:59.000Z

6

Superconducting RF systems for eRHIC  

Science Conference Proceedings (OSTI)

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.

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

2012-05-20T23:59:59.000Z

7

Automated Hydroforming of Seamless Superconducting RF Cavity  

SciTech Connect

We are studying the possibility of automated hydroforming process for seamless superconducting RF cavities. Preliminary hydroforming tests of three-cell cavities from seamless tubes made of C1020 copper have been performed. The key point of an automated forming is to monitor and strictly control some parameters such as operation time, internal pressure and material displacements. Especially, it is necessary for our studies to be able to control axial and radial deformation independently. We plan to perform the forming in two stages to increase the reliability of successful forming. In the first stage hydroforming by using intermediate constraint dies, three-cell cavities were successfully formed in less than 1 minute. In parallel, we did elongation tests on cavity-quality niobium and confirmed that it is possible to achieve an elongation of >64% in 2 stages that is required for our forming of 1.3 GHz cavities.

Nagata, Tomohiko [ULVAC, Inc.; Shinozawa, Seiichi [ULVAC, Inc.; Abe, Noriyuki [ULVAC, Inc.; Nagakubo, Junki [ULVAC, Inc.; Murakami, Hirohiko [ULVAC, Inc.; Tajima, Tsuyoshi [Los Alamos National Laboratory; Inoue, Hitoshi [High Energy Accelerator Research Organization, KEK; Yamanaka, Masashi [High Energy Accelerator Research Organization, KEK; Ueno, Kenji [High Energy Accelerator Research Organization, KEK

2012-07-31T23:59:59.000Z

8

Fast thermometry for superconducting rf cavity testing  

SciTech Connect

Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several resistance temperature detectors (RTDs) were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of the fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity.

Orris, Darryl; Bellantoni, Leo; Carcagno, Ruben H.; Edwards, Helen; Harms, Elvin Robert; Khabiboulline, Timergali N.; Kotelnikov, Sergey; Makulski, Andrzej; Nehring, Roger; Pischalnikov, Yuriy; /Fermilab

2007-06-01T23:59:59.000Z

9

Realization and modeling of rf superconducting quantum interference device metamaterials  

E-Print Network (OSTI)

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

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

2013-08-06T23:59:59.000Z

10

Superconducting RF Cavities Past, Present and Future  

E-Print Network (OSTI)

In the last two decades many laboratories around the world, notably Argonne (ANL), TJNAF (formerly CEBAF), CERN, DESY and KEK, decided to develop the technology of superconducting (SC) accelerating cavities. The aim was either to increase the accelerator energy or to save electrical consumption or both. This technology has been used extensively in the operating machines showing good performances and strong reliability. At present, the technology using bulk niobium (Nb) or Nb coated on copper (Cu) is mature enough to be applied for many different applications, such as synchrotron light sources and spallation neutron drivers. Results, R&D work and future projects will be presented with emphasis on application to linear accelerators.

Chiaveri, Enrico

2003-01-01T23:59:59.000Z

11

1.3 GHz superconducting RF cavity program at Fermilab  

SciTech Connect

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

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

2011-03-01T23:59:59.000Z

12

Cerenkov Radiator Driven by a Superconducting RF Electron Gun  

SciTech Connect

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.

Poole, B R; Harris, J R

2011-03-07T23:59:59.000Z

13

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

Office of Science (SC) Website

Superconducting laser photocathode RF Superconducting laser photocathode RF gun at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Superconducting laser photocathode RF gun at BNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Superconducting laser photocathode RF gun Developed at: Brookhaven National Laboratory (BNL), New York and Advanced Energy Systems,

14

Nanofabrication Research Staff Page  

Science Conference Proceedings (OSTI)

... Student Researchers. Sarice Barkley, CNST/UMD Research Assistant Sarice Barkley is a CNST/UMD Research Assistant in the Nanofabrication ...

2013-11-06T23:59:59.000Z

15

CFN | Nanofabrication Group  

NLE Websites -- All DOE Office Websites (Extended Search)

CFN People Center for Functional Nanomaterials An Office of Science User Facility Home Facilities Proximal Probes Nanofabrication Materials Synthesis and Characterization Theory...

16

Superconducting RF cavity R&D for future accelerators  

E-Print Network (OSTI)

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

C. M. Ginsburg

2009-10-22T23:59:59.000Z

17

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

Science Conference Proceedings (OSTI)

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.

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

2012-05-20T23:59:59.000Z

18

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

SciTech Connect

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.

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

2012-05-20T23:59:59.000Z

19

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

Science Conference Proceedings (OSTI)

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.

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

2005-04-13T23:59:59.000Z

20

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

Science Conference Proceedings (OSTI)

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

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

2012-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

Science Conference Proceedings (OSTI)

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.

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

2013-01-01T23:59:59.000Z

22

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

Science Conference Proceedings (OSTI)

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.

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

2009-04-13T23:59:59.000Z

23

rf  

NLE Websites -- All DOE Office Websites (Extended Search)

RF RF It's what makes the protons go 'round. The latest in a series explaining particle physics in everyday language. Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

24

RF Design and Operating Performance of the BNL/AES 1.3 GHz Single Cell Superconducting RF Photocathode Electron Gun  

SciTech Connect

Over the past several years Advanced Energy Systems and BNL have been collaborating on the development and testing of a fully superconducting photocathode electron gun. Over the past year we have begun to realize significant results which have been published elsewhere [1]. This paper will review the RF design of the gun under test and present results of its performance under various operating conditions. Results for cavity quality factor will be presented for various operating temperatures and cavity field gradients. We will also discuss future plans for testing using this gun.

Cole, Michael; Kneisel, Peter; Ben-Zvi, Ilan; Burrill, Andrew; Hahn, H.; Rao, Triveni; Zhao, Y.

2005-05-01T23:59:59.000Z

25

RF DESIGN AND OPERATING PERFORMANCE OF THE BNL/AES 1.3 GHZ SINGLE CELL SUPERCONDUCTING RF PHOTOCATHODE ELECTRON GUN.  

Science Conference Proceedings (OSTI)

Over the past several years Advanced Energy Systems and BNL have been collaborating on the development and testing of a fully superconducting photocathode electron gun. Over the past year we have begun to realize significant results which have been published elsewhere [1]. This paper will review the RF design of the gun under test and present results of its performance under various operating conditions. Results for cavity quality factor will be presented for various operating temperatures and cavity field gradients. We will also discuss future plans for testing using this gun.

COLE, M.; KNEISEL, P.; BEN-ZVI, I.; BURRILL, A.; HAHN, G.; RAO, T.; ZHAO, Y.

2005-05-16T23:59:59.000Z

26

Nanofabrication | Center for Functional Nanomaterials  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanofabrication Facility Nanofabrication Facility nanofabrication The Nanofabrication Facility is housed in a class 100/1000 clean room (5,000 sq. ft) dedicated to state-of-the art patterning and processing of thin films, nanomaterials, and devices. The instrumentation in the facility has been optimized to provide maximum flexibility for its users, with capabilities to pattern a variety of materials over a wide range of size scales, from 10 nanometers to 10 millimeters. The clean room is utilized to fabricate devices for nanoelectronics, nanophotonics, biomedical engineering, photovoltaics, x-ray optics, nanomagnetics and beyond. Capabilities High-resolution patterning by electron beam lithography, nanoimprint lithography, and optical lithography Thin-film deposition by electron beam and thermal evaporation, DC

27

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

Science Conference Proceedings (OSTI)

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.

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

2012-02-01T23:59:59.000Z

28

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

SciTech Connect

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

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

2012-08-29T23:59:59.000Z

29

Advanced nanofabrication of thermal emission devices  

E-Print Network (OSTI)

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

Hurley, Fergus (Fergus Gerard)

2008-01-01T23:59:59.000Z

30

RF-THERMAL COMBINED SIMULATIONS OF A SUPERCONDUCTING HOM COAXIAL COUPLER  

Science Conference Proceedings (OSTI)

To benchmark a multi-physics code VORPAL developed by Tech-X, the High Order Mode (HOM) coaxial coupler design implemented in Jefferson Lab?s 12GeV upgrade cryomodules is analyzed by use of commercial codes, such as ANSYS, HFSS and Microwave Studio. Testing data from a Horizontal Test Bench (HTB) experiment on a dual-cavity prototype are also utilized in the verification of simulation results. The work includes two stages: first, the HOM feedthrough that has a high RRR niobium probe and sapphire insulator is analyzed for the RF-thermal response when there is travelling wave passing through; second, the HTB testing condition is simulated and results from simulation are compared to thermal measurements from HTB tests. The analyses are of coupled-field nature and involve highly nonlinear temperature dependent thermal conductivities and electric resistivities for the eight types of materials used in the design. Accuracy and efficiency are the main factors in evaluation of the performance of the codes.

Guangfeng Cheng, Haipeng Wang, David Smithe

2011-09-01T23:59:59.000Z

31

Current Challenges and Physics of Superconducting Radio-Frequency...  

NLE Websites -- All DOE Office Websites (Extended Search)

Recent performance advances in superconducting RF (SRF) cavities have made RF superconductivity a vital technology for accelerators which serve a variety of experimental...

32

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

E-Print Network (OSTI)

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

Anders, Andre

2013-01-01T23:59:59.000Z

33

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

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

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

2010-10-28T23:59:59.000Z

34

Nanofabrication of gallium nitride photonic crystal light-emitting diodes  

Science Conference Proceedings (OSTI)

We describe a comparison of nanofabrication technologies for the fabrication of 2D photonic crystal structures on GaN/InGaN blue LEDs. Such devices exhibit enhanced brightness and the possibility of controlling the angular emission profile of emitted ... Keywords: GaN dry-etching, Light-emitting diodes, Nanolithography, Photonic crystals

Ali Z. Khokhar; Keith Parsons; Graham Hubbard; Faiz Rahman; Douglas S. Macintyre; Chang Xiong; David Massoubre; Zheng Gong; Nigel P. Johnson; Richard M. De La Rue; Ian M. Watson; Erdan Gu; Martin D. Dawson; Steve J. Abbott; Martin D. B. Charlton; Martin Tillin

2010-11-01T23:59:59.000Z

35

Eccentric rf deflecting structure  

SciTech Connect

For superconducting rf separators, assembled by electron beam welding techniques, two types of mode stabilizers are discussed: the elliptical structure, and a new design called the eccentric structure''. For an operating pi /2 or pi mode in the lower pass band, it is shown that the various parameters of the eccentric structure can be adjusted to provide the required frequency spacing between the operating mode and the upper dispersion curve. (auth)

Aggus, J.R.; Giordano, S.; Halama, H.J.

1973-12-13T23:59:59.000Z

36

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

SciTech Connect

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.

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

2010-07-02T23:59:59.000Z

37

R&D ERL: Low level RF  

SciTech Connect

A superconducting RF (SRF) Energy Recovery Linac (ERL) is currently under development at the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL). The major components from an RF perspective are (a) a 5-cell SRF ERL cavity, (b) an SRF photocathode electron gun, and (c) a drive laser for the photocathode gun. Each of these RF subsystems has its own set of RF performance requirements, as well as common requirements for ensuring correct synchronism between them. A low level RF (LLRF) control system is currently under development, which seeks to leverage both technology and experience gained from the recently commissioned RHIC LLRF system upgrade. This note will review the LLRF system requirements and describe the system to be installed at the ERL.

Smith, K.

2010-01-15T23:59:59.000Z

38

Dissipative hydride precipitates in superconducting niobium cavities  

Science Conference Proceedings (OSTI)

We report the first direct observation of the microstructural features exhibiting RF losses at high surface magnetic fields of above 100 mT in field emission free superconducting niobium cavities. The lossy areas were identified by advanced thermometry. Surface investigations using different techniques were carried out on cutout samples from lossy areas and showed the presence of dendritic niobium hydrides. This finding has possible implications to the mechanisms of RF losses in superconducting niobium at all field levels.

Romanenko, A.; Cooley, L.D.; /Fermilab; Ciovati, G.; / /Jefferson Lab; Wu, G.; /Argonne

2011-10-01T23:59:59.000Z

39

RF transformer  

DOE Patents (OSTI)

There is provided an improved RF transformer having a single-turn secondary of cylindrical shape and a coiled encapsulated primary contained within the secondary. The coil is tapered so that the narrowest separation between the primary and the secondary is at one end of the coil. The encapsulated primary is removable from the secondary so that a variety of different capacity primaries can be utilized with one secondary.

Smith, James L. (Naperville, IL); Helenberg, Harold W. (Calumet City, IL); Kilsdonk, Dennis J. (Joliet, IL)

1979-01-01T23:59:59.000Z

40

Rf system for the NSLS coherent infrared radiation source  

Science Conference Proceedings (OSTI)

The existing NSLS X-ray Lithography Source (XLS Phase I) is being considered for a coherent synchrotron radiation source. The existing 211 MHz warm cavity will be replaced with a 5-cell 2856 MHz superconducting RF cavity, driven by a series of 2 kW klystrons. The RF system will provide a total V{sub RF} of 1.5 MV to produce {sigma}{sub L} = 0.3 mm electron bunches at an energy of 150 MeV. Superconducting technology significantly reduces the required space and power needed to achieve the higher voltage. It is the purpose of this paper to describe the superconducting RF system and cavity, power requirements, and cavity design parameters such as input coupling, Quality Factor, and Higher Order Modes.

Broome, W.; Biscardi, R.; Keane, J.; Mortazavi, P.; Thomas, M.; Wang, J.M.

1995-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Fundamental Research in Superconducting RF Cavity Design  

Science Conference Proceedings (OSTI)

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.

Georg Hoffstaetter

2012-11-13T23:59:59.000Z

42

rf_shield.PDF  

NLE Websites -- All DOE Office Websites (Extended Search)

April 2001 Interaction Region RF Shield Issues G. Stupakov and T.O. Raubenheimer Stanford Linear Accelerator Center Stanford, California 102300 Interaction Region RF Shield...

43

Superconducting wire  

DOE Patents (OSTI)

This invention consists of a method of producing superconducting wire by drawing a glass fiber with a melted powder of a superconducting wire inside the glass tube. After drawing, the glass fiber is heated to crystallize the superconducting compound. The diameter of the superconducting wires is controlled by the rate at which the glass fiber s are drawn from the glass tube.

Day, D.E.; Petrovic, J.J.; Gac, F.D.; Ray, C.S.

1991-03-05T23:59:59.000Z

44

CFN Operations and Safety Awareness (COSA) Checklist Nanofabrication (Clean Room) Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanofabrication (Clean Room) Facility Nanofabrication (Clean Room) Facility Building 735 This COSA form must be completed for all experimenters working in the CFN and must be submitted to the CFN User Office for badge access. CFN Safety Awareness Policy: Each user must be instructed in the safe procedures in CFN related activities. CFN Facility Laboratory personnel shall keep readily available all relevant instructions and safety literature. Employee/Guest Name Life/Guest Number Department/Division ES&H Coordinator/Ext. Facility Manager COSA Trainer Guest User Staff USER ADMINISTRATION Checked in at User Administration and has valid BNL ID badge Safety Approval Form (SAF) approved. Training requirements completed (Indicate additional training specified in SAF or ESR in lines provided below):

45

Superconductive wire  

DOE Patents (OSTI)

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.

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

1995-01-01T23:59:59.000Z

46

Critical Magnetic Field Determination of Superconducting Materials  

Science Conference Proceedings (OSTI)

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, electric field at the sample surface. A model of the system is presented in this paper along with a discussion of preliminary experimental data.

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

2011-11-04T23:59:59.000Z

47

Superconductive wire  

DOE Patents (OSTI)

This invention is comprised of a superconductive article including a first metallic tube having an interior surface and an exterior surface, said interior surface defining an interior hollow cavity, a layer of superconductive material surrounding said exterior surface of said first metallic tube, and, a second metallic tube having an interior surface and an exterior surface, said interior surface adjacent to said layer of superconductive material is provided together with processes of making such a superconductive article including, e.g., 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 and/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.

Korzekwa, D.A.; Bingert, J.F.; Peterson, D.E.; Sheinberg, H.

1992-12-31T23:59:59.000Z

48

Rf Feedback free electron laser  

DOE Patents (OSTI)

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.

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

1981-01-01T23:59:59.000Z

49

Rf feedback free electron laser  

DOE Patents (OSTI)

A free electron laser system and electron beam system for a free electron laser are provided 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.

Brau, C.A.; Swenson, D.A.; Boyd, T.J. Jr.

1979-11-02T23:59:59.000Z

50

Radiolysis with RF Photoinjectors  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiolysis with RF Photoinjectors: Supercritical Xenon Chemistry James F. Wishart in "Femtosecond Beam Science" Uesaka, M., Ed.; Imperial College Press, London, in press. (ISBN...

51

Superconducting phase qubits  

E-Print Network (OSTI)

eld enhancement of superconductivity in ultranarrow wires.computation · Qubits · Superconductivity · Decoherence PACS

Martinis, John M.

2009-01-01T23:59:59.000Z

52

RHIC Superconducting Accelerator and Electron Cooling Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Organization Chart (PDF) Organization Chart (PDF) Accelerator R&D Division eRHIC R&D Energy Recovery Linac Photocathode R&D Superconducting RF Electron Cooling LARP Center for Accelerator Science and Education C-AD Accelerator R&D Division Superconducting RF Group Group Headed By: Sergey Belomestnykh This web site presents information on the Superconducting Accelerator and RHIC Electron Cooling Group, which is in the Accelerator R&D Division of the Collider-Accelerator Department of Brookhaven National Laboratory. Work is supported mainly by the Division of Nuclear Physics of the US Department of Energy. Upcoming Events: TBD Most recent events: 56 MHz 2nd External Review, March 8-9, 2011 External Review of the Energy Recovery Linac, February 17-18, 2010. Report of the Review Committee

53

ANALYZING SURFACE ROUGHNESS DEPENDENCE OF LINEAR RF LOSSES  

SciTech Connect

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.

Reece, Charles E. [JLAB; Kelley, Michael J. [JLAB, W& M College; Xu, Chen [JLAB, W& M College

2012-09-01T23:59:59.000Z

54

Phase stable rf transport system  

DOE Patents (OSTI)

This invention is comprised of an RF transport system which delivers a phase-stable RF signal to a load, such as an RF cavity of a charged particle accelerator. A circuit generates a calibration signal at an odd multiple frequency of the RF signal where the calibration signal is superimposed with the RF signal on a common cable that connects the RF signal with the load. Signal isolating diplexers are located at both the RF signal source end and load end of the common cable to enable the calibration to be inserted and extracted from the cable signals without any affect on the RF signal. Any phase shift in the calibration signal during traverse of the common cable is then functionally related to the phase shift in the RF signal. The calibration phase shift is used to control a phase shifter for the RF signal to maintain a stable RF signal at the load.

Curtin, M.T.; Natter, E.F.; Denney, P.M.

1991-02-19T23:59:59.000Z

55

Phase stable RF transport system  

DOE Patents (OSTI)

An RF transport system delivers a phase-stable RF signal to a load, such as an RF cavity of a charged particle accelerator. A circuit generates a calibration signal at an odd multiple frequency of the RF signal where the calibration signal is superimposed with the RF signal on a common cable that connects the RF signal with the load. Signal isolating diplexers are located at both the RF signal source end and load end of the common cable to enable the calibration to be inserted and extracted from the cable signals without any affect on the RF signal. Any phase shift in the calibration signal during traverse of the common cable is then functionally related to the phase shift in the RF signal. The calibration phase shift is used to control a phase shifter for the RF signal to maintain a stable RF signal at the load.

Curtin, Michael T. (Los Alamos, NM); Natter, Eckard F. (San Francisco, CA); Denney, Peter M. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

56

RF Conditioning and testing of fundamental power couplers for the RIA project  

DOE Green Energy (OSTI)

The Rare Isotope Accelerator (RIA) is the highest priority of the nuclear physics community in the United States for a major new accelerator facility. A principal element of RIA will be a superconducting 1.4 GeV superconducting ion linac accelerating ions of isotopes from hydrogen to uranium onto production targets or for further acceleration by a second superconducting linac. The superconducting linac technology is closely related to that used at existing accelerators and the Spallation Neutron Source. Taking advantage of JLAB's SRF Institute facilities and expertise for the SNS project, preparation of couplers, RF conditioning and high power tests have been performed on fundamental power couplers for RIA project.

M. Stirbet; J. Popielarski; T. L. Grimm; M. Johnson

2003-09-01T23:59:59.000Z

57

Supersymmetric color superconductivity  

E-Print Network (OSTI)

Supersymmetric Color Superconductivity 1 arXiv:hep-patterns such as color superconductivity and color-?avortional method in color superconductivity, namely µ ? ?. In

Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi

2003-01-01T23:59:59.000Z

58

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

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

59

COMPARISON OF RF CAVITY TRANSPORT MODELS FOR BBU SIMULATIONS  

Science Conference Proceedings (OSTI)

The transverse focusing effect in RF cavities plays a considerable role in beam dynamics for low-energy beamline sections and can contribute to beam breakup (BBU) instability. The purpose of this analysis is to examine RF cavity models in simulation codes which will be used for BBU experiments at Jefferson Lab and improve BBU simulation results. We review two RF cavity models in the simulation codes elegant and TDBBU (a BBU simulation code developed at Jefferson Lab). elegant can include the Rosenzweig-Serafini (R-S) model for the RF focusing effect. Whereas TDBBU uses a model from the code TRANSPORT which considers the adiabatic damping effect, but not the RF focusing effect. Quantitative comparisons are discussed for the CEBAF beamline. We also compare the R-S model with the results from numerical simulations for a CEBAF-type 5-cell superconducting cavity to validate the use of the R-S model as an improved low-energy RF cavity transport model in TDBBU. We have implemented the R-S model in TDBBU. It will improve BBU simulation results to be more matched with analytic calculations and experimental results.

Ilkyoung Shin,Byung Yunn,Todd Satogata,Shahid Ahmed

2011-03-01T23:59:59.000Z

60

ISG8-RF Sources  

NLE Websites -- All DOE Office Websites (Extended Search)

RF Sources - (WG3) RF Sources - (WG3) Orange Rm Yong Ho Chin, Christopher Nantista, and Sami G. Tantawi Parallel Sessions: Working Groups: WG1: Parameters, Design, Instrumentation and Tuning WG2: Damping Rings and ATF WG3: RF Sources WG4:Structures WG5: Ground Motion; Site Requirements and Investigations Monday Morning 9:00-10:30 Plenary Coffee Break 11:00-12:00 Planning Session. Monday Afternoon 13:30-15:30 High Gradient Issues (Joint with working group 4) Coffee Break 16:00-16:30 The 8-Pack Project -- D. Atkinson 16:30-17:30 High Gradient Issues and Discussions Continued. Tuesday Morning 9:30-10:30 Klystrons 9:30-10:00 Status of PPM Klystron Development for JLC -- Y. H. Chin 10:00-10:30 Design of 150MW Multi-Beam Klystron -- S. Matsumoto Coffee Break 11:00-11:30 Klystron Development at SLAC -- G. Caryotakis

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Overview and status of RF systems for the SSC Linac  

SciTech Connect

The Superconducting Super Collider (SSC) Linear Accelerator (Linac) produces a 600-MeV, 35-{mu}s, H-beam at a 10-Hz repetition rate. The beam is accelerated by a series of RF cavities. These consist of a Radio Frequency Quadrupole (RFQ), two bunchers, and four Drift Tube Linac (DTL) tanks at 427.617 MHz, and two bunchers, nine side-coupled Linac modules, and an energy compressor at 1282.851 MHz. The RFQ amplifier and the low-frequency buncher cavity amplifiers use gridded tubes, while the other cavities use klystron amplifier systems. The RF control system consists of a reference line and cavity feedback and feedforward loops for each amplifier. The RF amplifier system for each of these accelerator cavities is described, and the current status of each system is presented.

Mynk, J.; Grippe, J.; Cutler, R.I.; Rodriguez, R.

1993-05-01T23:59:59.000Z

62

Control of the LHC 400 MHz RF System (ACS)  

E-Print Network (OSTI)

The LHC ACS RF system is composed of 16 superconducting cavities, eight per ring. Each ring has two cryomodules, each containing four cavities. Each cavity is powered by a 300 kW klystron. The klystrons are grouped in fours, the klystrons in each group sharing a common 58 kV power converter and HV equipment bunker. The ACS RF control system is based on modern industrial programmable controllers (PLCs). A new fast interlock and alarm system with inbuilt diagnostics has been developed. Extensive use of the FIPIO Fieldbus drastically decreases the cabling complexity and brings improved signal quality, increased reliability and easier maintenance. Features of the implementation, such as system layout, communication and the high-level software interface are described. Operational facilities such as the automatic switch on procedure are described, as well as the necessary specialist tools and interfaces. A complete RF chain, including high voltage, cryomodule and klystron is presently being assembled in order to ch...

Arnaudon, L; Maesen, P; Prax, M

2004-01-01T23:59:59.000Z

63

Rf2a and rf2b transcription factors  

DOE Patents (OSTI)

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.

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

2007-10-02T23:59:59.000Z

64

Superconductive articles  

DOE Patents (OSTI)

An article of manufacture including a substrate, a patterned interlayer of magnesium oxide, barium-titanium oxide or barium-zirconium oxide, the patterned interlayer material overcoated with a secondary interlayer material of yttria-stabilized zirconia or magnesium-aluminum oxide, upon the surface of the substrate whereby an intermediate article with an exposed surface of both the overcoated patterned interlayer and the substrate is formed, a coating of a buffer layer selected from the group consisting of oxides of Ce, Y, Cm, Dy, Er, Eu, Fe, Gd, Ho, In, La, Mn, Lu, Nd, Pr, Pu, Sm, Tb, Tl, Tm, Y, and Yb over the entire exposed surface of the intermediate article, and, a ceramic superconductive material layer as an overcoat upon the buffer layer whereby the ceramic superconductive material situated directly above the substrate has a crystal structure substantially different than the ceramic superconductive material situated above the overcoated patterned interlayer.

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

1991-12-31T23:59:59.000Z

65

Superconducting cyclotrons  

SciTech Connect

Superconducting cyclotrons are particularly appropriate for acceleration of heavy ions. A review is given of design features of a superconducting cyclotron with energy 440 (Q$sup 2$/A) MeV. A strong magnetic field (4.6 tesla average) leads to small physical size (extraction radius 65 cm) and low construction costs. Operating costs are also low. The design is based on established technology (from present cyclotrons and from large bubble chambers). Two laboratories (in Chalk River, Canada and in East Lansing, Michigan) are proceeding with construction of full-scale prototype components for such cyclotrons.

Blosser, H.G.; Johnson, D.A.; Burleigh, R.J.

1976-01-01T23:59:59.000Z

66

Rf heating of mirrors  

SciTech Connect

A brief overview is presented of potential uses for rf heating of plasmas in mirror devices. While some discussion relating to past experiments is given, the main emphasis is devoted to a review of potential experiments in presently existing devices, and devices under construction or planning. Some predictions are made for plasmas in mirror reactors.

Porkolab, M.

1980-04-09T23:59:59.000Z

67

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

DOE Patents (OSTI)

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.

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

1986-01-01T23:59:59.000Z

68

Nanofabrication, Plasmon Enhanced Fluorescence and Photo-oxidation Kinetics of CdSe Nanoparticles  

E-Print Network (OSTI)

Unconventional nanofabrication techniques; both those which have been newly developed and those under development, had brought inexpensive, facile, yet high quality means to fabricate nanostructures that have feature sizes of less than 100 nm in industry and academia. This dissertation focuses on developing unconventional fabrication techniques, building studying platforms, and studying the mechanisms behind them. The studies are divided into two main facets and four chapters. The first facet, in Chapter II and Chapter III, deals with the research and development of different nanofabrication techniques and nanostructures. These techniques include litho-synthesis, colloidal lithography, and photolithography. The nanostructures that were fabricated by these techniques include the metal nanoparticle arrays, and the self-assembled CdSe nanoring arrays. At the same time, the dissertation provides mechanisms and models to describe the physical and chemical nature of these techniques. The second area of this study, in Chapter III to Chapter V, presents the applications of these nanostructures in fundamental studies, i.e. the mechanisms of plasmon enhanced fluorescence and photo-oxidation kinetics of CdSe quantum dots, and applications such as molecular sensing and material fabrication. More specifically, these applications include tuning the optical properties of CdSe quantum dots, biomodification of CdSe quantum dots, and copper ion detection using plasmon and photo enhanced CdSe quantum dots. We have successfully accomplished our research goals in this dissertation. Firstly, we were able to tune the emission wavelength of quantum dots, blue-shifted for up to 45 nm, and their surface functionalization with photo-oxidation. A kinetic model to calculate the photo-oxidation rates was established. Secondly, we established a simple mathematical model to explain the mechanism of plasmon enhanced fluoresce of quantum dots. Our calculation and experimental data support the fluorescence resonance energy transfer (FRET) mechanism between quantum dots and the metal nanoparticles. Thirdly, we successfully pattered the CdSe quantum dots (diameter ~4 nm) into nanorings with tunable diameters and annular sizes on different substrates. We also established a physical model to quantitatively explain the mechanism with the forces that involved in the formation of the nanorings.

Chen, Jixin

2010-05-01T23:59:59.000Z

69

Superconducting Power Equipment  

Science Conference Proceedings (OSTI)

The 2010 Electric Power Research Institute (EPRI) Technology Watch (Techwatch) report on superconducting power applications (EPRI report 1019995, Superconducting Power Equipment: Technology Watch 2010) introduced coverage about superconducting magnetic energy storage systems and superconducting transformers. The 2011 report contains additional information about superconducting power equipment, including progress to demonstrations in some projects. The 2011 report also includes a section on superconductin...

2011-12-22T23:59:59.000Z

70

Interband transitions and interference effects in superconducting qubits  

Science Conference Proceedings (OSTI)

We investigate phase-sensitive interference effects in a periodically sin(2¿ f rf t)-driven, artificial two-state system connected to a microwave resonator at f LC ¿ 800 MHz. We observe two ... Keywords: 73.23.Hk, 85.25.Cp, 85.35.Gv, Aharonov---Anandan phase, Franck---Condon physics, Landau---Zener tunneling, Multiphoton transitions, Superconducting qubits

Antti Paila; Jani Tuorila; Mika Sillanpää; David Gunnarsson; Jayanta Sarkar; Yuriy Makhlin; Erkki Thuneberg; Pertti Hakonen

2009-06-01T23:59:59.000Z

71

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC S. Schreiber for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract During 1997 and 1998 a first accelerator module was tested successfully at the TESLA Test Facility Linac (TTFL) at DESY. Eight superconducting

72

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC S. Schreiber£ for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract The TESLA Test Facility Linac (TTFL) at DESY uses two modules with 8 TESLA superconducting accelerat- ing structures each to accelerate an electron

73

Superconductivity Conference Held  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Conference Held Z.-X. Shen SSRL sponsored a major international conference on superconductivity early this year. The conference, entitled "Spectroscopies in Novel...

74

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

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

Hassenzahl, W.

2011-01-01T23:59:59.000Z

75

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

Scale Superconducting Magnetic Energy Storage Plant", IEEEfor SlIperconducting Magnetic Energy Storage Unit", inSuperconducting Magnetic Energy Storage Plant, Advances in

Hassenzahl, W.

2011-01-01T23:59:59.000Z

76

RF current sensor  

DOE Patents (OSTI)

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.

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

1998-11-10T23:59:59.000Z

77

Superconducting wires  

SciTech Connect

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.

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

1988-06-01T23:59:59.000Z

78

NSLS-II RF SYSTEMS  

Science Conference Proceedings (OSTI)

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.

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

2011-03-28T23:59:59.000Z

79

Closed-cell 201.25 MHz RF structures for a muon cooling channel  

DOE Green Energy (OSTI)

We report on the research and development of high gradient low frequency closed-cell structures for possible use in a muon cooling channel. The presence of strong magnetic fields precludes the use of superconducting RF. These multi-cell structures have the ''beam iris'' closed by conducting oils, grids of tubes or other isolating structures. This greatly increases the shunt impedance and also allows the individually powered cells to be set independently to any phase. The isolating structure must be made using a very small amount of low-Z material to avoid unacceptable scattering of the muon beam. Various cell designs and methods of closure are presented and compared. The problems of RF heating and breakdown at high gradient are discussed with regard to the vulnerable isolating structures. RF, thermal and stress analyses are presented and the integration of the RF with the solenoid cryostat and liquid hydrogen absorbers is considered.

Rimmer, R.; Hartman, N.; Ladran, A.; Li, D.; Moretti, A.; Jurgens, T.

2001-06-01T23:59:59.000Z

80

MSTC - Microsystems Science, Technology, and Components - RF...  

NLE Websites -- All DOE Office Websites (Extended Search)

capability for the unique demands of National Security. Communications RF MEMS Passive wireless sensorsRFIDsTags RF system minaturization For additional information or...

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

DOE Patents (OSTI)

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.

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

1984-01-01T23:59:59.000Z

82

Spectroscopy of {sup 257}Rf.  

Science Conference Proceedings (OSTI)

The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti,n){sup 257}Rf. Reaction products were separated and identified by mass. Delayed spectroscopy of {sup 257}Rf and its decay products was performed. A partial decay scheme with configuration assignments is proposed based on hindrance factors. The excitation energy of the 1/2{sup +}[620] configuration in {sup 253}No is proposed. The energy of this 1/2{sup +} state in a series of N=151 isotones increases with nuclear charge, reflecting an increase in the N=152 gap. This gap is deduced to grow substantially from 850 to 1400 keV between Z=94 and 102. An isomeric state in {sup 257}Rf, with a half-life of 160{sub -31}{sup +42} {micro}s, was discovered by detecting internal conversion electrons followed by decay. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal conversion electrons, with a half-life of 4.1{sub -1.3}{sup +2.4} s, followed by decay, was also observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf. Fission of {sup 257}Rf was unambiguously detected, with a branching ratio of b{sub Rf}{sup SF} = 0.02 {+-} 0.01.

Qian, J.; Heinz, A.; Khoo, T. L.; Janssens, R. V. F.; Peterson, D.; Seweryniak, D.; Ahmad, I.; Asai, M.; Back, B. B.; Carpenter, M. P.; Garnsworthy, A. B.; Greene, J. P.; Hecht, A. A.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Robinson, A.; Savard, G.; Scott, R.; Vondrasek, R.; Wang, X.; Winkler, R.; Zhu, S.; Yale Univ.; Japan Atomic Energy Agency; Univ. of Surrey; Univ. of Maryland

2009-06-01T23:59:59.000Z

83

Spectroscopy of {sup 257}Rf  

Science Conference Proceedings (OSTI)

The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti,n){sup 257}Rf. Reaction products were separated and identified by mass. Delayed spectroscopy of {sup 257}Rf and its decay products was performed. A partial decay scheme with configuration assignments is proposed based on {alpha} hindrance factors. The excitation energy of the 1/2{sup +}[620] configuration in {sup 253}No is proposed. The energy of this 1/2{sup +} state in a series of N=151 isotones increases with nuclear charge, reflecting an increase in the N=152 gap. This gap is deduced to grow substantially from 850 to 1400 keV between Z=94 and 102. An isomeric state in {sup 257}Rf, with a half-life of 160{sub -31}{sup +42} {mu}s, was discovered by detecting internal conversion electrons followed by {alpha} decay. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal conversion electrons, with a half-life of 4.1{sub -1.3}{sup +2.4} s, followed by {alpha} decay, was also observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf. Fission of {sup 257}Rf was unambiguously detected, with a branching ratio of b{sub Rf}{sup SF}=0.02{+-}0.01.

Qian, J.; Heinz, A.; Winkler, R. [WNSL, Yale University, New Haven, Connecticut 06511 (United States); Khoo, T. L.; Janssens, R. V. F.; Peterson, D.; Seweryniak, D.; Ahmad, I.; Back, B. B.; Carpenter, M. P.; Greene, J. P.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Robinson, A.; Savard, G.; Scott, R.; Vondrasek, R.; Wang, X. [Argonne National Laboratory, Illinois 60439 (United States)] (and others)

2009-06-15T23:59:59.000Z

84

High power tests of dressed supconducting 1.3 GHz RF cavities  

SciTech Connect

A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted ('dressed') with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

Hocker, A.; Harms, E.R.; Lunin, A.; Sukhanov, A.; /Fermilab

2011-03-01T23:59:59.000Z

85

Superconducting magnet  

DOE Patents (OSTI)

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.

Satti, John A. (Naperville, IL)

1980-01-01T23:59:59.000Z

86

Booster Subharmonic RF Capture Design  

NLE Websites -- All DOE Office Websites (Extended Search)

require a < (1 40 ns) 25 MHz subharmonic frequency. Due to the difficulty of building high-voltage low-frequency rf cavities, this requirement can be relaxed so that at least...

87

Secrets of superconductivity revealed  

NLE Websites -- All DOE Office Websites (Extended Search)

Secrets of superconductivity revealed 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 superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) "Superconductivity continues to give new surprises. As its secrets are revealed, we learn more about the quantum world of electrons and can begin

88

Secrets of superconductivity revealed  

NLE Websites -- All DOE Office Websites (Extended Search)

Secrets of superconductivity revealed 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 superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) "Superconductivity continues to give new surprises. As its secrets are revealed, we learn more about the quantum world of electrons and can begin

89

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

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

Wang, Shannon Xuanyue

90

Boron: Modeling, Superconductivity  

Science Conference Proceedings (OSTI)

Oct 8, 2012 ... Boron, Boron Compounds, and Boron Nanomaterials: Structure, Properties, Processing and Applications: Boron: Modeling, Superconductivity

91

High Temperature Superconductivity Partners | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Temperature Superconductivity Partners High Temperature Superconductivity Partners Map showing DOE's partnersstakeholders in the High Temperature Superconductivity Program...

92

Basic principle of superconductivity  

E-Print Network (OSTI)

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

Tian De Cao

2007-08-23T23:59:59.000Z

93

Superconductivity Program Overview High-Temperature Superconductivity  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SuperconducTiviTy program haS Three FocuS areaS: 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 currents over long lengths Superconductivity Program Overview High-Temperature Superconductivity for Electric Systems Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585

94

Fast Ferroelectric L-Band Tuner for Superconducting Cavities  

Science Conference Proceedings (OSTI)

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.

Jay L. Hirshfield

2012-07-03T23:59:59.000Z

95

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

SciTech Connect

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.

De Silva, Payagalage Subashini Uddika [JLAB, Old Dominion U.; Delayen, Jean Roger [Old Dominion U.

2012-09-01T23:59:59.000Z

96

Status of the plasma generator of the superconducting proton linac  

SciTech Connect

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.

Kronberger, M.; Lettry, J.; Paoluzzi, M.; Pereira, H.; Arias, J. Sanchez; Schmitzer, C.; Scrivens, R. [European Organisation for Nuclear Research, CERN, 1211 Geneva 23 (Switzerland); Faircloth, D. [STFC, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom)

2012-02-15T23:59:59.000Z

97

RF & Microwave Systems Group The RF & Microwave Systems  

E-Print Network (OSTI)

for Technology Transfer. Tagging, Tracking, and Locating Systems TTL technologies are on the verge and development (R&D) geared toward supplying robust communications for extreme environments; global tagging, tracking, and locating (TTL) systems; and RF- and microwave- based measurement and processing systems

98

Superconductive radiofrequency window assembly  

DOE Patents (OSTI)

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.

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

1998-05-19T23:59:59.000Z

99

Superconducting radiofrequency window assembly  

DOE Patents (OSTI)

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.

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

1997-03-11T23:59:59.000Z

100

Simulation of synchrotron motion with rf noise  

Science Conference Proceedings (OSTI)

The theoretical formulation is described that is behind an algorithm for synchrotron phase-space tracking with rf noise and some preliminary simulation results of bunch diffusion under rf noise obtained by actual tracking.

Leemann, B.T.; Forest, E.; Chattopadhyay, S.

1986-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

MSTC - Microsystems Science, Technology, and Components - RF...  

NLE Websites -- All DOE Office Websites (Extended Search)

band RF input and supplies N identical outputs (N4 or 8). SiGe, GaAs, GaN RFICs. Passive RF detectors - Pyroelectric microdetectors that produce a DC output proportional to...

102

Superconducting Power Cables  

Science Conference Proceedings (OSTI)

Power cables constructed from superconducting materials are being realized in utility demonstrations within the United States. Cooled by liquid nitrogen, high temperature superconducting power cables can transfer large amounts of power through relatively small cross sections. The key to their high power capacity is the high current density inherent with superconductors; a superconducting wire can conduct several times as much current as copper or aluminum conductors of the same cross section. For the pas...

2006-11-30T23:59:59.000Z

103

Superconducting Power Cables  

Science Conference Proceedings (OSTI)

This report is a continuation of a Technology Watch series on superconducting power cables that summarize full-scale superconducting cable projects throughout the world ranging from full-scale test installations to utility demonstration projects. The report covers various aspects of each project from design to implementation. When available, updated status regarding operation and maintenance (O&M) also is presented. The report will serve as a knowledge resource on the status of superconducting cable tech...

2008-12-19T23:59:59.000Z

104

High-Power Rf Load  

DOE Patents (OSTI)

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.

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

1998-09-01T23:59:59.000Z

105

Superconductive interconnections for cryoelectronics  

Science Conference Proceedings (OSTI)

Factors affecting the use of superconducting interconnections for cryoelectronics will be examined. The fundamental questions to be answered are why interconnections are important for high performance computing

Kenneth Rose

1992-01-01T23:59:59.000Z

106

Superconducting VAR control  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

107

Superconductive imaging surface magnetometer  

DOE Patents (OSTI)

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.

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

1991-01-01T23:59:59.000Z

108

Modulation instability in RF MEMS devices  

Science Conference Proceedings (OSTI)

Modulation instability generated by mechanical frequencies in RF MEMS switches is predicted and its potential contribution to the RF signal degradation is discussed. In particular, evaluations have been performed for double clamped configurations in ... Keywords: Modulation instability, Nonlinear Schrodinger equation, Power handling, RF MEMS

Romolo Marcelli; Giancarlo Bartolucci; Giorgio Angelis; Andrea Lucibello; Emanuela Proietti

2012-04-01T23:59:59.000Z

109

Superconducting phase qubits  

Science Conference Proceedings (OSTI)

Experimental progress is reviewed for superconducting phase qubit research at the University of California, Santa Barbara. The phase qubit has a potential advantage of scalability, based on the low impedance of the device and the ability to microfabricate ... Keywords: 03.65.Yz, 03.67.Lx, 85.25.Cp, Decoherence, Quantum computation, Qubits, Superconductivity

John M. Martinis

2009-06-01T23:59:59.000Z

110

Superconducting thermoelectric generator  

DOE Patents (OSTI)

This invention is comprised of 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 higher thermal conductivity than that of the superconducting material. 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.

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

1992-12-31T23:59:59.000Z

111

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

Science Conference Proceedings (OSTI)

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.

Dowell, D.H.; /SLAC; Lewellen, J.W.; /Argonne; Nguyen, D.; /Los Alamos; Rimmer, R.; /Jefferson Lab

2006-03-13T23:59:59.000Z

112

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

SciTech Connect

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.

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

2005-03-19T23:59:59.000Z

113

Rf System for the NLCTA  

Science Conference Proceedings (OSTI)

This paper describes an X-Band RF system for the Next Linear Collider Test Accelerator. The RF system consists of a 90 MeV injector and a 540 MeV linac. The main components of the injector are two low-Q single-cavity prebunchers and two 0.9-m-long detuned accelerator sections. The linac system consists of six 1.8-m-long detuned and damped detuned accelerator sections powered in pairs. The rf power generation, compression, delivery, distribution and measurement systems consist of klystrons, SLEDII energy compression systems, rectangular waveguides, magic-T's, and directional couplers. The phase and amplitude for each prebuncher is adjusted via a magic-T type phase shifter/attenuator. Correct phasing between the two 0.9 m accelerator sections is obtained by properly aligning the sections and adjusting two squeeze type phase shifters. Bunch phase and bunch length can be monitored with special microwave cavities and measurement systems. The design, fabrication, microwave measurement, calibration, and operation of the sub-systems and their components are briefly presented.

Wang, J.W.; /SLAC; Adolphsen, C.; Eichner, J.; Fuller, R.W.; Gold, S.L.; Hanna, S.M.; Hoag, H.A.; Holmes, S.G.; Koontz, R.F.; Lavine, Theodore L.; Loewen, R.J.; Miller, R.H.; Nantista, C.D.; Pope, R.; Rifkin, J.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, Z.; Yeremian, A.; /SLAC

2011-08-26T23:59:59.000Z

114

Low jitter RF distribution system  

SciTech Connect

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.

Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

2012-09-18T23:59:59.000Z

115

The TESLA superconducting linear collider  

Science Conference Proceedings (OSTI)

This paper summarizes the present status of the studies for a superconducting Linear Collider (TESLA).

R. Brinkmann; the TESLA Collaboration

1997-01-01T23:59:59.000Z

116

High Gradient Operation with the CEBAF Upgrade RF Control System  

SciTech Connect

The CEBAF Accelerator at Jefferson Lab is presently a 6 GeV five pass electron accelerator consisting of two superconducting linacs joined by independent magnetic transport arcs. Energy will be upgraded to 12 GeV with the addition of 10 new high gradient cryomodules (17+ MV/m). The higher gradients pose significant challenges beyond what the present analog low level RF (LLRF) control systems can handle reliably; therefore, a new LLRF control system is needed. A prototype system has been developed incorporating a large FPGA and using digital down and up conversion to minimize the need for analog components. The new system is more flexible and less susceptible to drifts and component nonlinearities. Because resonance control is critical to reach high gradients quickly, the new cryomodules will include a piezoelectric tuner for each cavity, and the LLRF controls must incorporate both feedback and feed-forward methods to achieve optimal resonance control performance. This paper discusses development of the new RF system, system performance for phase and amplitude stability and resonance control under Lorentz detuning measured during recent tests on a prototype cryomodule.

J. Hovater; G. Davis; Hai Dong; Alicia Hofler; Lawrence King; John Musson; Tomasz Plawski

2006-08-16T23:59:59.000Z

117

Superconducting materials for large scale applications  

E-Print Network (OSTI)

IEEE Trans. Applied Superconductivity, vol. 12, pp.4. “Power Applications of Superconductivity,” in Handbookof Applied Superconductivity, B. Seeber, ed. , Bristol, UK:

Scanlan, Ronald M.; Malozemoff, Alexis P.; Larbalestier, David C.

2004-01-01T23:59:59.000Z

118

6.763 Applied Superconductivity, Fall 2001  

E-Print Network (OSTI)

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

Orlando, Terry P.

119

Introduction to Color Superconductivity  

E-Print Network (OSTI)

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

G. Nardulli

2006-10-23T23:59:59.000Z

120

Superconducting active impedance converter  

DOE Patents (OSTI)

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.

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

1993-11-16T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Single electron beam rf feedback free electron laser  

DOE Patents (OSTI)

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.

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

1981-02-11T23:59:59.000Z

122

Some aspects of superconducting accelerator design  

SciTech Connect

The performance of an accelerator can be characterized by the efficiency with which electrical energy, the minimumm energy needed to generate a given beam voltage. The current accelerator improvement program at SLAC aims at raising the beam voltage to 50 GV which will use 240 klystrons each capable of producing a pulse 5 ..mu..s in length at a peak power of 36 MW. The Linear Collider requires 50 MW klystrons to achieve 60 GV which will raise the concomittant power consumption to 32.3 MW. We show that with superconducting elements we can increase the rf and ac conversion efficiencies and achieve the necessary 50 GV using only 1/3 of the present power requirements, provided that we exclude CW operation. We will further demonstrate that this increase in efficiency is crucial and highly significant in the design of a proposed 1000 GV linear accelerator.

Farkas, Z.D.; St. Lorant, S.J.

1982-11-01T23:59:59.000Z

123

Overview of the RF Systems for LCLS  

SciTech Connect

The Linac Coherent Light Source (LCLS) at SLAC, when it becomes operational in 2009, will provide its user community with an X-ray source many orders of magnitude brighter than anything available in the world at that time [1]. The electron beam acceleration will be provided by existing and new RF systems capable of maintaining the amplitude and phase stability of each bunch to extremely tight tolerances. RF feedback control of the various RF systems will be fundamental in ensuring the beam arrives at the LCLS undulator at precisely the required energy and peak current phase. This paper details the requirements for RF stability for the various LCLS RF systems and also highlights proposals for how these injector and Linac RF systems can meet these tight constraints.

McIntosh, P.; Akre, R.; Boyce, R.; Emma, P.; Hill, A.; Rago, C.; /SLAC

2005-06-15T23:59:59.000Z

124

Overview of the RF Systems for LCLS  

E-Print Network (OSTI)

The Linac Coherent Light Source (LCLS) at SLAC, when it becomes operational in 2009, will provide its user community with an X-ray source many orders of magnitude brighter than anything available in the world at that time. The electron beam acceleration will be provided by existing and new RF systems capable of maintaining the amplitude and phase stability of each bunch to extremely tight tolerances. RF feedback control of the various RF systems will be fundamental in ensuring the beam arrives at the LCLS undulator at precisely the required energy and phase. This paper details the requirements for RF stability for the various LCLS RF systems and also highlights proposals for how these injector and Linac RF systems can meet these constraints.

McIntosh, Peter; Boyce, Richard; Emma, Paul; Hill, Alan; Rago, Carl

2005-01-01T23:59:59.000Z

125

Decay Study of {sup 257}Rf  

Science Conference Proceedings (OSTI)

The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti, n){sup 257}Rf. Reaction products were separated by the Argonne Fragment Mass Analyzer. Radioactive decay and spontaneous fission of {sup 257}Rf and its decay products were investigated. An isomeric state in {sup 257}Rf, with a half-life of 160{sub -31}{sup 42} {mu}S, was discovered by detecting internal conversion electrons followed by alpha decays. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal-conversion electrons which were succeeded by alpha decay, with a half-life of 4.1{sub -1.3}{sup +2.4} s, was observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf, or from another isomer in {sup 257}Rf.

Qian, J.; Heinz, A.; Winkler, R. [Yale University, New Haven, CT 06511 (United States); Janssens, R. V. F.; Khoo, T. L.; Seweryniak, D.; Peterson, D.; Back, B. B.; Carpenter, M. P.; Greene, J. P.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Pardo, R. C.; Robinson, A.; Scott, R.; Vondrasek, R.; Wang, X.; Zhu, S. [Argonne National Laboratory, Argonne, IL 60439 (United States)] (and others)

2009-03-04T23:59:59.000Z

126

Superconducting thermoelectric generator  

DOE Patents (OSTI)

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.

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

1998-05-05T23:59:59.000Z

127

Experimental work on superconductivity  

Science Conference Proceedings (OSTI)

The high thermal conductivity in the superconductive state at low reduced critical temperatures has been used for the detection of metal imperfections, including those caused by radiation damage. A statistically disordered single crystal of Ta with 30% ...

K. Mendelssohn

1962-01-01T23:59:59.000Z

128

Superconducting thermoelectric generator  

DOE Patents (OSTI)

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.

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

1998-01-01T23:59:59.000Z

129

Superconducting thermoelectric generator  

DOE Patents (OSTI)

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.

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

1996-01-01T23:59:59.000Z

130

Alexei Abrikosov and Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Alexei Abrikosov and Superconductivity Alexei Abrikosov and Superconductivity Resources with Additional Information · Publications at ANL Alexei A. Abrikosov of the U.S. Department of Energy's Argonne National Laboratory (ANL) is a recipient of the 2003 Nobel Prize in Physics for his research in the area of superconductivity. Alexei Abrikosov Courtesy Argonne National Laboratory "Abrikosov's research [at ANL] centers on condensed-matter physics (the structure and behavior of solids and liquids), and concentrates on superconductivity, the ability of some materials to carry electrical current without resistance. He was the first to propose the concept of "type-II superconductors" in 1952 and constructed the theory of their magnetic properties, known as the Abrikosov vortex lattice.

131

High voltage RF feedthrough bushing  

DOE Patents (OSTI)

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.

Grotz, Glenn F. (Huntington Station, NY)

1984-01-01T23:59:59.000Z

132

Superconducting Power Cables  

Science Conference Proceedings (OSTI)

This report is the fourth installment of a Technology Watch series on Superconducting Power Cables that summarize full-scale superconducting cable projects throughout the world. The series provides an overview of technical fundamentals and status updates on ongoing development efforts ranging from full-scale test installations to grid-deployed demonstration projects. This installment of the series covers ongoing full-scale utility installations and proposed demonstration projects worldwide. Information a...

2009-12-23T23:59:59.000Z

133

New Superconducting Materials  

Science Conference Proceedings (OSTI)

Superconductors with higher superconducting transition temperatures, higher critical currents, and better mechanical properties would be valuable. This report presents criteria to guide the search for higher transition temperature materials. To determine if candidate materials are suitably metallic, the study carried out detailed electronic structure calculations. These calculations identified boron-containing hydrides as particularly promising as a new class of possible superconducting materials that ma...

1994-11-04T23:59:59.000Z

134

A Survey of the Urban RF Environment  

Science Conference Proceedings (OSTI)

The prevalence of sources of radio-frequency (RF) electromagnetic fields is expanding at a rapid pace.  As new wireless technologies are deployed (e.g., smart meters), questions are often raised as to what extent people are exposed to their RF emissions, and what if any effects on health and safety the RF could possibly cause. To obtain a frame of reference for the contributions of new sources to our environment, this study was designed to quantify the levels of RF fields that already exist in ...

2012-12-31T23:59:59.000Z

135

Characteristics of multiantenna rf ion source  

Science Conference Proceedings (OSTI)

We have developed a new multiantenna rf ion source for neutral beam injection and studied the effects of different antennas connected in parallel

T. Shoji; Y. Oka; NBI Group

2006-01-01T23:59:59.000Z

136

Passive RF Components - Microsystems Science, Technology, and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Passive RF Components Microsystems Home Custom Microsystems Solutions Microsystems R&D Services Capabilities and Technologies Facilities Trusted Microsystems General Info About Us...

137

Superconducting transmission line particle detector  

DOE Patents (OSTI)

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.

Gray, K.E.

1988-07-28T23:59:59.000Z

138

Superconducting transmission line particle detector  

DOE Patents (OSTI)

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.

Gray, Kenneth E. (Naperville, IL)

1989-01-01T23:59:59.000Z

139

Superconducting radiofrequency window assembly  

DOE Patents (OSTI)

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.

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

1997-01-01T23:59:59.000Z

140

Superconductive radiofrequency window assembly  

DOE Patents (OSTI)

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.

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

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

High temperature interfacial superconductivity  

DOE Patents (OSTI)

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.

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

2012-06-19T23:59:59.000Z

142

Recent Studies of RF Breakdown Physics in Normal Conducting Cavities  

SciTech Connect

The operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The behavior of the rf breakdown depends on multiple parameters, including the input rf power, rf circuit, cavity shape and material. Here we discuss recent experimental data and theoretical studies of rf breakdown physics.

Dolgashev, Valery; /SLAC

2012-06-11T23:59:59.000Z

143

DOE Superconductivity Program Stakeholders | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Stakeholders Map showing the stakeholders involved in High Temperature Superconductivity work with the DOE. DOE Superconductivity Program Stakeholders More Documents &...

144

Fast Ferroelectric L-Band Tuner for Superconducting Cavities  

Science Conference Proceedings (OSTI)

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.

Jay L. Hirshfield

2011-03-01T23:59:59.000Z

145

Superconducting solenoids for the MICE channel  

DOE Green Energy (OSTI)

This report describes the channel of superconductingsolenoids for the proposed international Muon Ionization CoolingExperiment (MICE). MICE consists of two cells of a SFOFO cooling channelthat is similar to that studied in the level 2 study of a neutrinofactory[1]. MICE also consists of two detector solenoids at either end ofthe cooling channel section. The superconducting solenoids for MICEperform three functions. The coupling solenoids, which are largesolenoids around 201.25 MHz RF cavities, couple the muon beam between thefocusing sections as it passes along the cooling channel. The focusingsolenoids are around the liquid hydrogen absorber that reduces themomentum of the muons in all directions. These solenoids generate agradient field along the axis as they reduce the beta of the muon beambefore it enters the absorber. Each detector solenoid system consists offive coils that match the muon beam coming to or from an absorber to a4.0 T uniform solenoidal field section that that contains the particledetectors at the ends of the experiment. There are detector solenoids atthe beginning and at the end of the experiment. This report describes theparameters of the eighteen superconducting coils that make up the MICEmagnetic channel.

Green, M.A.; Barr, G.; Baynham, D.E.; Rockford, J.H.; Fabbricatore, P.; Farinin, S.; Palmer, R.B.; Rey, J.M.

2003-05-01T23:59:59.000Z

146

Options for an 11 GeV RF Beam Separator for the Jefferson Lab CEBAF Upgrade  

Science Conference Proceedings (OSTI)

The CEBAF accelerator at Jefferson Lab has had, since first demonstration in 1996, the ability to deliver a 5-pass electron beam to experimental halls (A, B, and C) simultaneously. This capability was provided by a set of three, room temperature 499 MHz rf separators in the 5th pass beamline. The separator was two-rod, TEM mode type resonator, which has a high shunt impedance. The maximum rf power to deflect the 6 GeV beams was about 3.4kW. The 12 GeV baseline design does not preserve the capability of separating the 5th pass, 11 GeV beam for the 3 existing halls. Several options for restoring this capability, including extension of the present room temperature system or a new superconducting design in combination with magnetic systems, are under investigation and are presented.

Jean Delayen, Michael Spata, Haipeng Wang

2009-05-01T23:59:59.000Z

147

Carbon-Fibre-Reinforced Laminates for the Tuning Structure of the LHC RF Cavities  

E-Print Network (OSTI)

A carbon-fibre-reinforced tube is proposed for the tuning structure of the superconducting RF cavities of the Large Hadron Collider (LHC). It has a high axial stiffness and provides thermal insulation between the cold RF cavity and the tuning actuator at room temperature. The tube is subjected to a high number of mechanical load cycles, high temperature gradients, thermal cycling, and ionizing radiation. Laminate theory is applied to a simplified model of the tube for a failure analysis. Long duration fatigue tests under nominal mechanical and thermal loads were performed on two tubes. The tubes were examined before and after the fatigue tests by geometric measurements, microscopy, and ultrasonic inspection. No damage such as fibre breakage, delamination, or matrix micro cracking could be detected.

Pflanz, G; Tischhauser, Johann

1997-01-01T23:59:59.000Z

148

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ENERGY STAR Referral (RF-330SS) Sunpentown: ENERGY STAR Referral (RF-330SS) May 10, 2013 DOE referred the matter of Sunpentown-brand refrigerator, model RF-330SS, manufactured by...

149

Samsung: ENERGY STAR Referral (RF26VAB) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Samsung: ENERGY STAR Referral (RF26VAB) Samsung: ENERGY STAR Referral (RF26VAB) March 16, 2010 DOE referred the matter of Samsung refrigerator-freezer model RF26VAB to the U.S....

150

An NMR investigation of superconductivity and antiferromagnetism in CaFe2As2 under pressure  

Science Conference Proceedings (OSTI)

We report {sup 75}As NMR measurements in CaFe{sub 2}As{sub 2}, made under applied pressures up to 0.83 CPa produced by a standard clamp pressure cell. Our data reveal phase segregation of paramagnetic (PM) and antiferromagnetic (AFM) phases over a range of pressures, with the AFM phase more than 90% dominant at low temperatures. In situ RF susceptibility measurements indicate the presence of superconductivity. {sup 75}As spin-lattice relaxation experiments indicate that the {sup 75}As nuclei sample the superconductivity while in the magnetically-ordered environment.

Baek, Seung H [Los Alamos National Laboratory; Lee, Han O [Los Alamos National Laboratory; Bauer, E D [Los Alamos National Laboratory; Ronning, F [Los Alamos National Laboratory; Park, T [Los Alamos National Laboratory; Thompson, J D [Los Alamos National Laboratory; Brown, S E [UCLA; Curro, N J [UC DAVIS

2009-01-01T23:59:59.000Z

151

Relativistic mechanism of superconductivity  

E-Print Network (OSTI)

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

H. Y. Cui

2002-12-17T23:59:59.000Z

152

Fluorinated Precursors of Superconducting Ceramics ...  

Fluorinated precursors for superconducting ceramics typically increase the critical current in the ... Applications and Industries. High-temperature ...

153

Argonne TDC: Superconductive Components, Inc.  

Unlocking the Potential of High-Temperature Superconductors . Superconductive Components, Inc. Columbus, Ohio. For bulk applications of high-temperature ...

154

Argonne TDC: Superconductive Components, Inc.  

High-Performance Tailored Materials for Levitation Permanent Magnet Technologies Making materials to help advance flywheel energy storage. Superconductive Components ...

155

Linear Gain for the Microbunching Instability in an RF Compressor  

E-Print Network (OSTI)

Instability in an RF Compressor M. Venturini Lawrencefor investigating this instability in rf compressors. We useapplied to magnetic compressors [2, 3] and derive some

Venturini, M.

2010-01-01T23:59:59.000Z

156

Possibility of color magnetic superconductivity  

E-Print Network (OSTI)

Two aspects of quark matter at high density are addressed: one is color superconductivity and the other is ferromagnetism. We are mainly concerned with the latter and its relation to color superconductivity, which we call "color magnetic superconductivity". The relation of ferromagnetism and chiral symmetry restoration is also discussed.

Toshitaka Tatsumi; Tomoyuki Maruyama; Eiji Nakano

2003-12-26T23:59:59.000Z

157

Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

3 - 6/13/06 3 - 6/13/06 Superconducting Magnet Division S&T Committee Program Review June 22-23, 2006 Conference Room A, Bldg. 725, BNL DRAFT AGENDA Thursday, June 22 0830 Executive Session to address the charge S. Aronson (25 min) 0855 Welcome S. Aronson (5 min) 0900 Superconducting Magnet Division Status & M. Harrison (45 + 15 min) Issues - mission statement, core competencies, themes, program, problems, etc. 1000 Themes - Nb3Sn, HTS, Direct wind, Accelerator integration, P. Wanderer (20 + 10 min) rapid cycling Core Competencies 1030 Superconducting Materials A. Ghosh (20 + 5 min) 1055 Break 1110 Magnetic Design R. Gupta (20 + 5 min) 1135 Magnet Construction M. Anerella (20 + 5 min) 1200 Magnet Testing G. Ganetis (20 + 5 min)

158

LANL: Superconductivity Technology Center  

NLE Websites -- All DOE Office Websites (Extended Search)

Sitemap | Lab Home | Phone Sitemap | Lab Home | Phone ABOUT LANL ContactsPhonebookPolicy CenterOrganizationMapsJobs Emergency NEWS LIBRARY JOBS Search Materials Physics & Applications: STC STC Home OUR FOCUS HTS Physics HTS Materials Development HTS Materials Processing Power Applications Electronic Materials FUTURE APPLICATIONS Biomedical Developments Magnetic Levitation Train MHD Ship CONTACTS Center Leader Ken Marken Program Administrator Brenda Espinoza Center Office Location: TA-03, Bdg. 0032, Rm. 141 Exploring technology at STC Superconductivity Technology Center (STC) The Superconductivity Technology Center (STC) coordinates a multidisciplinary program for research, development, and technology transfer in the area of high-temperature superconductivity. Our focus is on effective collaborations with American industry, universities, and other national laboratories to develop electric power and electronic device applications of high-temperature superconductors (HTS).

159

Orbit Spaces in Superconductivity  

E-Print Network (OSTI)

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

Vittorino Talamini

2006-07-30T23:59:59.000Z

160

Superconducting active impedance converter  

DOE Patents (OSTI)

This invention is comprised of 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.

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

1992-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

E-Print Network (OSTI)

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

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

162

Models of Holographic superconductivity  

E-Print Network (OSTI)

We construct general models for holographic superconductivity parametrized by three couplings which are functions of a real scalar field and show that under general assumptions they describe superconducting phase transitions. While some features are universal and model independent, important aspects of the quantum critical behavior strongly depend on the choice of couplings, such as the order of the phase transition and critical exponents of second-order phase transitions. In particular, we study a one-parameter model where the phase transition changes from second to first order above some critical value of the parameter and a model with tunable critical exponents.

Francesco Aprile; Jorge G. Russo

2009-12-02T23:59:59.000Z

163

Superconductivity | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Highlights Research Highlights Superconductivity Neutron diffraction reveals semiconducting phase and contributes to new understanding of iron-based superconductors Contact: Huibo Cao New VULCAN tests of Japanese cable for US ITER's central magnet system (2012) Contact: Ke An ARCS maps collaborative magnetic spin behavior in iron telluride (2011) Published Work: "Unconventional Temperature Enhanced Magnetism in Fe1:1Te" Contact: Igor Zaliznyak Doug Scalapino discusses "common thread" linking unconventional superconducting materials (2011) Contact: Douglas Scalapino Materials Engineering Research at SNS Helps International Collaboration on Fusion Energy Scientists and engineers at ORNL are working with the ITER Organization and the Japanese Atomic Energy Agency to resolve issues with a critical

164

Matching network for RF plasma source  

DOE Patents (OSTI)

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.

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

2007-11-20T23:59:59.000Z

165

Review of the APS SR RF systems.  

DOE Green Energy (OSTI)

The Advanced Photon Source (APS) is a 7-GeV full energy storage ring (SR) for generating synchrotron radiation with an injector. The storage ring cavities consist of four groups of four single cells powered by up to four 1-MW klystrons for up to 300-mA operation. A review of the operation of the rf system as well as rf-related beam dynamics is presented. This review includes rf power distribution, low-level feedback, control law, beam loading, beam instabilities, higher-order modes, and beam-induced multipactoring.

Song, J.J.; Cours, A.; Grelick, A.; Harkay, K.; Horan, D.; Kang, Y.W.; Kustom, R.L.; Nassiri, A.; Pile, G.; Smith, T.L.

1998-03-31T23:59:59.000Z

166

Free-standing superconductive articles  

DOE Patents (OSTI)

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, the ceramic superconductive material layer and the protective material layer, removing the protective material layer from the composite structure whereby a substrate-free, free-standing ceramic superconductive film remains.

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

1991-12-31T23:59:59.000Z

167

Dimensional Metrology for Nanofabrication  

Science Conference Proceedings (OSTI)

... to model and simulate the line edge roughness power spectrum in ... 25 nm structures which are the foundation of next generation electronics and ...

2012-10-05T23:59:59.000Z

168

Nanofabrication Research Group Homepage  

Science Conference Proceedings (OSTI)

... the accumulated emission from a large number of gas phase atoms ... local environmental properties of individual nanoparticles in liquid environments ...

2012-10-02T23:59:59.000Z

169

Nanofabrication, Nanomanufacturing, and Nanoprocessing ...  

Science Conference Proceedings (OSTI)

... Directed Self-Assembly; Electron Beam Lithography (EBL); Focused Ion Beam Milling (FIB); Inspection; Interference Lithography; ...

2013-01-02T23:59:59.000Z

170

Langmuir vacuum and superconductivity  

SciTech Connect

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.

Veklenko, B. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2012-06-15T23:59:59.000Z

171

Superconductivity for Electric Systems  

E-Print Network (OSTI)

and Energy Reliability ­ Superconductivity for Electric Systems #12;3 Control Milestones and Status Control Milestone Due Date Status Section 1.1: Wire Development. · Short sample RABiTS using slot-die MOD CeO2 cap manufacturing process. Highlights: 1) HTS Program CPS Control Milestone Met - Short sample RABiTS using slot

172

Superconductivity and electron tunneling  

Science Conference Proceedings (OSTI)

Experiments on the tunneling of electrons through a thin dielectric layer separating two superconducting metals are reported. Data are presented for the pairs AI-Pb, Sn-Pb, and In-Sn. Particular attention is paid to the form of the tunneling current ...

S. Shapiro; P. H. Smith; J. Nicol; J. L. Miles; P. F. Strong

1962-01-01T23:59:59.000Z

173

Superconducting thermoelectric generator  

DOE Patents (OSTI)

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.

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

1994-01-01T23:59:59.000Z

174

SUPERCONDUCTING VANADIUM BASE ALLOY  

DOE Patents (OSTI)

A new vanadium-base alloy which possesses remarkable superconducting properties is presented. The alloy consists of approximately one atomic percent of palladium, the balance being vanadium. The alloy is stated to be useful in a cryotron in digital computer circuits.

Cleary, H.J.

1958-10-21T23:59:59.000Z

175

Normal zone propagation in superconducting focusing solenoids and related quench protection issues  

SciTech Connect

Superconducting solenoids are increasingly used as focusing lenses in transport channels of proton linear RF accelerators. If these accelerators employ superconducting RF cavities, each focusing lens is usually comprised of three coils connected in series: a main coil, which provides the needed focusing strength, and two bucking coils, that help to reduce magnetic field outside the lens. When a normal zone develops in any of the coils in a focusing lens, it propagates with a direction and a rate which depends on the coil and the specific part of the coil in which the quench first occurred. As a result of this propagation process (quenching), the temperature and/or voltage of parts of the lens can exceed safe limits, thus compromising lens reliability. On the other hand, the negative impact of quench events can be significantly mitigated if an external resistor is used to absorb a part of the energy stored in the magnetic field. This paper presents the main results of a solenoid quench protection study based on computational modeling of normal zone propagation in solenoid lenses being built for a superconducting linear RF accelerator under development at Fermilab.

Terechkine, I.; /Fermilab

2007-06-01T23:59:59.000Z

176

RF Micro Devices | Open Energy Information  

Open Energy Info (EERE)

National Center for Photovoltaics Partnership Year 2009 LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now RF Micro Devices is a company located in...

177

SLAC Linac RF Performance for LCLS *  

E-Print Network (OSTI)

The Linac Coherent Light Source (LCLS) project at SLAC uses a dense 15 GeV electron beam passing through a long undulator to generate extremely bright x-rays at 1.5 angstroms. The project requires electron bunches with a nominal peak current of 3.5kA and bunch lengths of 0.020mm (70fs). The bunch compression techniques used to achieve the high brightness impose challenging tolerances on the accelerator RF phase and amplitude. The results of measurements on the existing SLAC linac RF phase and amplitude stability are summarised and improvements needed to meet the LCLS tolerances are discussed. 1 LCLS RF REQUIREMENTS LCLS requires the SLAC linac to perform with tolerances on RF phase and amplitude stability which are beyond all previous requirements. The LCLS is divided into four linacs L0, L1, L2, and L3 [1]. The phase and amplitude tolerances for the four linacs operated at S-

unknown authors

2000-01-01T23:59:59.000Z

178

Deeply scaled CMOS for RF power applications  

E-Print Network (OSTI)

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

Scholvin, Jörg, 1976-

2006-01-01T23:59:59.000Z

179

Vortex formation during rf heating of plasma  

SciTech Connect

Experiments on a test plasma show that the linear theory of waveguide coupling to slow plasma waves begins to break down if the rf power flux exceeds approx. 30 W/cm/sup 2/. Probe measurements reveal that within 30 ..mu..s an undulation appears in the surface plasma near the mouth of the twin waveguide. This surface readjustment is part of a vortex, or off-center convective cell, driven by asymmetric rf heating of the plasma column.

Motley, R.W.

1980-05-01T23:59:59.000Z

180

High Power RF Sources for Accelerators  

SciTech Connect

This presentation describes RF sources developed and under development at Calabazas Creek Research, Inc. for driving high power accelerators and colliders. The RF sources range from L-Band to W-Band and power levels from 10s of kilowatts CW to 200 MW pulsed. The configurations include standard klystrons, multiple beam klystrons, sheet beam devices, and gyroklystrons. The basic parameters are presented with a basic description of operation and applications.

Ives, Lawrence; Read, Michael; Neilson, Jeff; Borchard, Philipp; Mizuhara, Max [Calabazas Creek Research, Inc., 690 Port Drive, San Mateo, CA 94404 (United States); Lawson, Wesley [Insitute for Research in Applied Physics, University of Maryland, College Park, MD 20742 (United States)

2006-11-27T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

AFRD - Superconducting Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Magnets Superconducting Magnets Home Organization Diversity Safety Links Gallery/History Updated July 2008 Ever-stronger magnets (which must be cost-effective as well) are a key to building tomorrow's high-energy accelerators and upgrading today's. Our role— not only a leading R&D group but also the administrators of the multi-institutional National Conductor Development Program— to create both evolutionary improvements and paradigm shifts in the application of accelerator magnets, providing innovative technology that enables new science. Improvements in conductor, innovative structures to solve the challenges of high fields and brittle superconductors, and integration of computerized design and analysis tools are key. The performance requirements of modern accelerators continue to press the

182

Equilibrium Distributions and Superconductivity  

E-Print Network (OSTI)

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

Ashot Vagharshakyan

2011-06-07T23:59:59.000Z

183

Superconducting magnet wire  

DOE Patents (OSTI)

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..

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

1986-01-01T23:59:59.000Z

184

Superconducting magnet of Aurora  

Science Conference Proceedings (OSTI)

The AURORAsuperconducting magnet system is composed of a cylindrical single?body magnet and a refrigeration system for superconducting coils. The magnet generates B z =1 T on the central orbit at the 150 MeV electron beam injection energy and B z =4.3 T at the 650 MeV storage energy. The diameter of the central orbit is 1 m. Iron poles and yokes are used for shielding the magnetic field

T. Takayama; SHI Accelerator Research Group

1989-01-01T23:59:59.000Z

185

Crystalline Color Superconductivity  

E-Print Network (OSTI)

We give an introduction crystalline color superconductivity, arguing that it is likely to occur wherever quark matter in which color-flavor locking does not occur is found. We survey the properties of this form of quark matter, and argue that its presence in a compact star may result in pulsar glitches, and thus in observable consequences. However, elucidation of this proposal requires an understanding of the crystal structure, which is not yet in hand.

Krishna Rajagopal

2001-09-14T23:59:59.000Z

186

Solitons in SO(5) Superconductivity  

E-Print Network (OSTI)

A model unifying superconductivity and antiferromagnetism using an underlying approximate SO(5) symmetry has injected energy into the field of high-temperature superconductivity. This model might lead to a variety of interesting solitons. In this paper, the idea that superconducting vortices may have antiferromagnetic cores is presented, along with the results of some preliminary numerical work. An outlook for future work, including speculations about other possible exotic solitons, is presented. 1

R. Mackenzie; Québec Hc J; J. M. Cline

1999-01-01T23:59:59.000Z

187

Superconducting Cable Construction and Testing  

Science Conference Proceedings (OSTI)

Superconducting cables, carrying three to five times more power than conventional cables, can meet increasing power demands in urban areas via retrofit applications. These high capacity cables will allow utilities to greatly enhance capacity, thereby giving the grid more flexibility and reliability. This report describes the development, construction, and testing of a superconducting cable system. Background In the late eighties, a new class of ceramic oxides was discovered with superconducting propertie...

2000-11-10T23:59:59.000Z

188

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Topological Insulators Print 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 resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be 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 electrical resistance in the surface states all the way to zero.

189

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Topological Insulators Print 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 resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be 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 electrical resistance in the surface states all the way to zero.

190

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Topological Insulators Print 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 resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be 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 electrical resistance in the surface states all the way to zero.

191

Flavor Superconductivity & Superfluidity  

E-Print Network (OSTI)

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

Matthias Kaminski

2010-02-25T23:59:59.000Z

192

Magnetically leviated superconducting bearing  

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

193

Superconducting magnetic energy storage  

DOE Green Energy (OSTI)

Long-time varying-daily, weekly, and seasonal-power demands require the electric utility industry to have installed generating capacity in excess of the average load. Energy storage can reduce the requirement for less efficient excess generating capacity used to meet peak load demands. Short-time fluctuations in electric power can occur as negatively damped oscillations in complex power systems with generators connected by long transmission lines. Superconducting inductors with their associated converter systems are under development for both load leveling and transmission line stabilization in electric utility systems. Superconducting magnetic energy storage (SMES) is based upon the phenomenon of the nearly lossless behavior of superconductors. Application is, in principal, efficient since the electromagnetic energy can be transferred to and from the storage coils without any intermediate conversion to other energy forms. Results from a reference design for a 10-GWh SMES unit for load leveling are presented. The conceptual engineering design of a 30-MJ, 10-MW energy storage coil is discussed with regard to system stabilization, and tests of a small scale, 100-KJ SMES system are presented. Some results of experiments are provided from a related technology based program which uses superconducting inductive energy storage to drive fusion plasmas.

Rogers, J.D.; Boenig, H.J.; Hassenzahl, W.V.; Schermer, R.I.

1978-01-01T23:59:59.000Z

194

Superconductivity and Superfluidity  

E-Print Network (OSTI)

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

B. V. Vasiliev

2010-08-16T23:59:59.000Z

195

Competition between singlet and triplet superconductivity  

E-Print Network (OSTI)

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

Tian De Cao; Tie Bang Wang

2009-05-15T23:59:59.000Z

196

Hall effect in superconducting films  

E-Print Network (OSTI)

Near the superconducting phase transition, fluctuations significantly modify the electronic transport properties. Here we study the fluctuation corrections to the Hall conductivity in disordered films, extending previous ...

Michaeli, Karen

197

Superconducting VAR control. [Patent application  

DOE Patents (OSTI)

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.

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

1980-12-05T23:59:59.000Z

198

High Pressure Studies of Superconductivity.  

E-Print Network (OSTI)

??Superconductivity has been studied extensively since it was first discovered over 100 years ago. High pressure studies, in particular, have been vital in furthering our… (more)

Hillier, Narelle Jayne

2013-01-01T23:59:59.000Z

199

High-Temperature Superconductivity Cable Demonstration Projects...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High-Temperature Superconductivity Cable Demonstration Projects High-Temperature Superconductivity Cable Demonstration Projects A National Effort to Introduce New Technology into...

200

Superconductivity Program Overview | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Program Overview Superconductivity Program Overview High-Temperature Superconductivity (HTS) has the potential for achieving a more fundamental change to electric power...

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Thermal activation of superconducting Josephson junctions  

E-Print Network (OSTI)

Superconducting quantum circuits (SQCs) are being explored as model systems for scalable quantum computing architectures. Josephson junctions are extensively used in superconducting quantum interference devices (SQUIDs) ...

Devalapalli, Aditya P. (Aditya Prakash)

2007-01-01T23:59:59.000Z

202

Prospects for Advanced RF Theory and Modeling  

SciTech Connect

This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed.

Batchelor, D.B.

1999-04-12T23:59:59.000Z

203

Power superconducting power transmission cable  

DOE Patents (OSTI)

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.

Ashworth, Stephen P. (Cambridge, GB)

2003-01-01T23:59:59.000Z

204

Superconductivity Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Superconductivity SHARE Superconductivity Highlights 1-6 of 6 Results Doug Scalapino discusses "common thread" linking unconventional superconducting materials December 01, 2012 - Douglas Scalapino was the inaugural speaker for a new joint lecture series sponsored by the Spallation Neutron Source and the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory. New VULCAN tests of Japanese cable for US ITER's central magnet system February 01, 2012 - Neutron testing of the Japanese-made superconducting cable for the central solenoid (CS) magnetic system for US ITER begins next Tuesday, says Ke An, lead instrument scientist for the VULCAN Engineering Materials Diffractometer at the Spallation Neutron Source. ARCS maps collaborative magnetic spin behavior in iron telluride

205

DOE Superconductivity Program Stakeholders  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Air Force Research Laboratory Air Force Research Laboratory Air Liquide Air Products and Chemicals Inc. American Electric Power American Superconductor Argonne National Laboratory BOC Group Brookhaven National Laboratory Composite Technology Development Consolidated Edison Cryo-Industries of America Inc. Delta Star Inc. Directed Vapor Technologies Department of Defense Department of Homeland Security Electric Power Research Institute Entergy Florida State University Long Island Power Authority Los Alamos National Laboratory Metal Oxide Technologies Inc. Mipox International Corp. National Grid National Institute for Standards & Tech. National Renewable Energy Laboratory Nissan Electric Co. Ltd. Nexans nkt Cables Group Oak Ridge National Laboratory Oxford Superconducting Technology Pacific Gas and Electric

206

Superconducting dipole electromagnet  

DOE Patents (OSTI)

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

Purcell, John R. (San Diego, CA)

1977-07-26T23:59:59.000Z

207

Precursor of Color Superconductivity  

E-Print Network (OSTI)

We investigate possible precursory phenomena of color superconductivity at finite temperature $T$ with an effective theory of QCD. It is found that the fluctuation of the diquark pair field exists with a prominent strength even well above the critical temperature $T_c$. We show that such a fluctuaiton forms a collective mode, the corresponding pole of which approaches the origin as $T$ is lowered to $T_c$ in the complex energy plane. We discuss the possible relevance of the precursor to the observables to be detected in heavy-ion collisions.

M. Kitazawa; T. Koide; T. Kunihiro; Y. Nemoto

2002-12-06T23:59:59.000Z

208

Superconducting magnet cooling system  

DOE Patents (OSTI)

A device is provided for cooling a conductor to the superconducting state. The conductor is positioned within an inner conduit through which is flowing a supercooled liquid coolant in physical contact with the conductor. The inner conduit is positioned within an outer conduit so that an annular open space is formed therebetween. Through the annular space is flowing coolant in the boiling liquid state. Heat generated by the conductor is transferred by convection within the supercooled liquid coolant to the inner wall of the inner conduit and then is removed by the boiling liquid coolant, making the heat removal from the conductor relatively independent of conductor length.

Vander Arend, Peter C. (Center Valley, PA); Fowler, William B. (St. Charles, IL)

1977-01-01T23:59:59.000Z

209

RF design of X-band RF deflector for femtosecond diagnostics of LCLS electron beam  

Science Conference Proceedings (OSTI)

We designed a successful constant impedance traveling wave X-band rf deflector for electron beam diagnostics at the 14 GeV SLAC Linac Coherent Light Source (LCLS). This is the first practical deflector built with a waveguide coupler. The 1-meter rf deflector produces 24 MeV peak transverse kick when powered with 20 MW of 11.424 GHz rf. The design is based on our experience with high gradient X-band accelerating structures. Several deflectors of this design have been built at SLAC and are currently in use. Here we describe the design and distinguishing features of this device.

Dolgashev, Valery A.; Wang Juwen [SLAC National Accelerator Laboratory, Menlo Park, CA, 94025 (United States)

2012-12-21T23:59:59.000Z

210

Tubular RF cage field confinement cavity - Energy Innovation ...  

An RF cavity is provided with a plurality of tubes that are formed into a tubular cage in a predefined shape to define the RF cavity. A selected number of tubes and a ...

211

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

E-Print Network (OSTI)

EFFICIENCY LOOP” FOR THE ALS STORAGE RING RF SYSTEM* S.at the Advanced Light Source (ALS) in order to decrease thethe cavities. 1 INTRODUCTION ALS Storage Ring RF system is

Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

2002-01-01T23:59:59.000Z

212

Transient beam loading in the ALS harmonic RF system  

E-Print Network (OSTI)

TRANSIENT BEAM LOADING IN THE ALS HARMONIC RF SYSTEM * J.as the Advanced Light Source (ALS), with moderately low beamharmonic RF system on the ALS storage ring consisting of 5

2000-01-01T23:59:59.000Z

213

Cw rf operation of the FMIT RFQ  

SciTech Connect

The 80-MHz RFQ for the Fusion Materials Irradiation Test Facility prototype accelerator has been rf conditioned for cw operation to the design field level of 17.5 MV/m (1.68 x Kilpatrick limit). Experimental results and operating experience will be discussed.

Fazio, M.V.; Brandeberry, F.E.

1985-01-01T23:59:59.000Z

214

RF Breakdown of Metallic Surfaces in Hydrogen  

DOE Green Energy (OSTI)

In earlier reports, microscopic images of the surfaces of metallic electrodes used in high-pressure gas-filled 805 MHz RF cavity experiments were used to investigate the mechanism of RF breakdown of tungsten, molybdenum, and beryllium electrode surfaces. Plots of remnants were consistent with the breakdown events being due to field emission, due to the quantum mechanical tunnelling of electrons through a barrier as described by Fowler and Nordheim. In the work described here, these studies have been extended to include tin, aluminium, and copper. Contamination of the surfaces, discovered after the experiments concluded, have cast some doubt on the proper qualities to assign to the metallic surfaces. However, two significant results are noted. First, the maximum stable RF gradient of contaminated copper electrodes is higher than for a clean surface. Second, the addition of as little as 0.01% of SF6 to the hydrogen gas increased the maximum stable gradient, which implies that models of RF breakdown in hydrogen gas will be important to the study of metallic breakdown.

BastaniNejad, M.; Elmustafa, A.A.; /Old Dominion U.; Yonehara, K.; Chung, M.; Jansson, A.; Hu, M.; Moretti, A.; Popovic, M.; /Fermilab; Alsharo'a, M.; Neubauer, M.; Sah, R.; /Muons Inc., Batavia

2009-05-01T23:59:59.000Z

215

RF Design of the LCLS Gun  

Science Conference Proceedings (OSTI)

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.

Limborg-Deprey, C

2010-12-13T23:59:59.000Z

216

BeginPackage "rfPack`" Modified 28 Jul 1999  

E-Print Network (OSTI)

voltage vRF, stable phase angle £ in units of 2¥ , and wavelength ¤ ." bucketHF::usage ¡ "bucketHF ¢ ,h compaction ¢ , an RF system with harmonic number h, peak voltage vRF, and stable phase angle £ in units of 2 with harmonic number h, peak voltage vRF, and stable phase angle £ in units of 2¥ , for particles of energy E

Keil, Eberhard

217

Color Superconductivity in Asymmetric Matter  

E-Print Network (OSTI)

The influence of different chemical potential for different flavors on color superconductivity is analyzed. It is found that there is a first order transition as the asymmetry grows. This transition proceeds through the formation of bubbles of low density, flavor asymmetric normal phase inside a high density, superconducting phase with a gap {\\it larger} than the one found in the symmetric case. For small fixed asymmetries the system is normal at low densities and superconducting only above some critical density. For larger asymmetries the two massless quarks system stays in the mixed state for arbitrarily high densities.

Paulo F. Bedaque

1999-10-06T23:59:59.000Z

218

Superconducting structure with layers of niobium nitride and aluminum nitride  

DOE Patents (OSTI)

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.

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

1989-07-04T23:59:59.000Z

219

Superconductivity, Superfluidity and Holography  

E-Print Network (OSTI)

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

Alberto Salvio

2013-01-02T23:59:59.000Z

220

Superconducting coil protection  

SciTech Connect

The protection system is based on a two-phase construction program. Phase I is the development of a reliable hardwired relay control system with a digital loop utilizing firmware and a microprocessor controller. Phase II is an expansion of the digital loop to include many heretofore unmonitored coil variables. These new monitored variables will be utilized to establish early quench detection and to formulate confirmation techniques of the quench detection mechanism. Established quench detection methods are discussed and a new approach to quench detection is presented. The new circuit is insensitive to external pulsed magnetic fields and the associated induced voltages. Reliability aspects of the coil protection system are discussed with respect to shutdowns of superconducting coil systems. Redundance and digital system methods are presented as related topics. (auth)

Woods, E.L.

1975-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Superconducting combined function magnets  

SciTech Connect

Superconducting accelerators and storage rings, presently under construction or in the design phase, are based on separate dipole and quadrupole magnets. It is here suggested that a hybrid lattice configuration consisting of dipoles and combined function gradient magnets would: (1) reduce the number of magnet units and their total cost; and (2) increase the filling factor and thus the energy at a given field. Coil cross sections are presented for the example of the Brookhaven Colliding Beam Accelerator. An asymmetric two-layer cable gradient magnet would have transfer functions of 10.42 G/A and 0.628 G cm/sup -1//A versus 15.77 G/A and 2.03 G cm/sup -1//A of the present separate dipoles and quadrupoles.

Hahn, H.; Fernow, R.C.

1983-01-01T23:59:59.000Z

222

Superconducting energy storage  

DOE Green Energy (OSTI)

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.

Giese, R.F.

1993-10-01T23:59:59.000Z

223

Superconducting magnetic coil  

DOE Patents (OSTI)

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.

Aized, D.; Schwall, R.E.

1999-06-22T23:59:59.000Z

224

Superconducting magnetic energy storage  

SciTech Connect

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.

Hassenzahl, W.

1988-08-01T23:59:59.000Z

225

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

Office of Science (SC) Website

such as electron cooling of hadron colliders, electron-ion colliders, high-power Free-Electron Lasers, high-brightness synchrotron radiation user facilities and much more....

226

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

NLE Websites -- All DOE Office Websites (Extended Search)

Harmonic Buncher Tandem Accelerator Super Buncher Linac-1 Linac-2 Linac-3 Re- Buncher SM-1 SM-2 HES SC1 SC2 LHe & LN 2 Inter-University Accelerator Centre, New Delhi Pelletron...

227

DESIGN AND PRELIMINARY TEST OF THE 1500 MHZ NSLS-II PASSIVE SUPERCONDUCTING RF CAVITY  

SciTech Connect

NSLS-II is a new ultra-bright 3 GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. Ion clearing gaps are required to suppress ion effects on the beam. The natural bunch length of 3mm is planned to be lengthened by means of a third harmonic cavity in order to increase the Touschek limited lifetime. Earlier work described the design alternatives and the geometry selected for a copper prototype. We subsequently have iterated the design to lower the R/Q of the cavity and to increase the diameter of the beam pipe ferrite HOM dampers to reduce the wakefield heating. A niobium cavity and full cryomodule including LN2 shield, magnetic shield and insulating vacuum vessel have been fabricated and installed. A passive SRF 3rd harmonic cavity consisting of two tightly coupled cells has been designed and fabricated for NSLS-II. Initial cold tests of this cavity are very promising. These tests have verified that the cavity frequency and mode separation between the 0 and {pi}-modes can be set at manufacture. Further, the frequency separation can be maintained over wide tuning ranges necessary for operation. Future work includes HOM damper and motorized tuner development.

Rose, J.; Gash, W.; Kosciuk, B.; Ravindranath, V.; Sikora, B.; Sharma, S.; Towne, N.; Grimm, T.L.; Boulware, C.H.; Krizmanich, C.; Kuhlman, B.; Miller, N.; Siegel, B.; Winowski, M.

2011-03-28T23:59:59.000Z

228

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

Office of Science (SC) Website

Energy Systems, New York Developed in: 2004-2007 Result of NP research: Electron cooling R&D for RHIC Application currently being supported by: DOD, DOE Impactbenefit to spin-off...

229

Focusing solenoid for the front end of a linear RF accelerator  

SciTech Connect

A prototype of a superconducting focusing solenoid for use in an RF linac has been built and tested at Fermi National Accelerator Laboratory (FNAL). The solenoid is comprised of the main coil, two bucking coils, two dipole corrector windings, and a low carbon steel flux return. At the excitation current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 5 G on the axis at a distance of 150 mm from the center. The length of the solenoid is 150 mm; the length of a cryovessel for the solenoid with a 20 mm diameter 'warm' bore is 270 mm. This paper presents the main design features of the focusing solenoid and discusses results from tests of the solenoid.

Terechkine, I.; Kashikhin, V.V.; Page, T.; Tartaglia, M.; Tompkins, J.; /Fermilab

2007-06-01T23:59:59.000Z

230

High Tc Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) Extensive research efforts to study the novel electronic properties of high-Tc superconductors and their related materials by angle-resolved photoemission spectroscopy at a recently commissioned Beam Line 5-4 (led by Z.-X. Shen) continue to be successful, producing many important results. These results, which are highlighted by five articles recently published in Physical Review Letters and one in Science, brought our understanding steps closer to solving the mystery of the high-Tc superconductivity. With the development of the latest generation of ultra-high resolution electron spectrometers in the past few years, the technique of angle resolved photoemission spectroscopy (ARPES) has recently experienced a renaissance. Nowhere is this revolution more evident than in the study of the high-temperature superconductors, which more than a decade after their discovery, continue to defy theoretical explanation. Recent ARPES experiments performed at Beam Line 5-4 have led to critical new discoveries about the fundamental nature of these mysterious superconductors and are now changing the way that the physics community views these materials. An excellent benchmark for the huge leap in detector resolution and technology is the recent work on Sr2RuO4. Although it belongs to a slightly different family than the high- temperature superconductors, its exotic superconducting mechanism (Tc = 1K) and complex electronic structure make it itself a fascinating material. In the past, due to poor resolutions, ARPES studies on this material were in disagreement with theory and other experimental techniques.

231

Brett Parker | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Brett Parker Brett Parker Recent Presentations "BNL Direct Wind Magnets," (pdf) presentation dedicated to the memory of Pat Thompson given at the 22nd Magnet Technology Conference (MT22), September 11 - 16, 2011, Marseille, France A Review of BNL Direct-Wind Superconducting IR Magnet Experience, (pdf) presented at the 30th Advanced ICFA Beam Dynamics Workshop on High Luminosity e+e- Collisions, October 13 - 16, 2003, Stanford, California The Serpentine Coil Design for BEPC-II Superconducting IR Magnets, (pdf) presented at the "Mini-Workshop on BEPC-II IR Design", January 12 - 16, 2004, Beijing, P.R. China Ma nufacture of a Superconducting Octupole Magnet for the ALPHA Experiment at CERN using the Direct Wind Machine Presentations Prior to 2004 Superconducting Final Focus Magnet Issues (pdf), presented at

232

Partial Deconfinement in Color Superconductivity  

E-Print Network (OSTI)

We analyze the fate of the unbroken SU(2) color gauge interactions for 2 light flavors color superconductivity at non zero temperature. Using a simple model we compute the deconfining/confining critical temperature and show that is smaller than the critical temperature for the onset of the superconductive state itself. The breaking of Lorentz invariance, induced already at zero temperature by the quark chemical potential, is shown to heavily affect the value of the critical temperature and all of the relevant features related to the deconfining transition. Modifying the Polyakov loop model to describe the SU(2) immersed in the diquark medium we argue that the deconfinement transition is second order. Having constructed part of the equation of state for the 2 color superconducting phase at low temperatures our results are relevant for the physics of compact objects featuring a two flavor color superconductive state.

F. Sannino; N. Marchal; W. Schäfer

2002-02-26T23:59:59.000Z

233

QUENCHES IN LARGE SUPERCONDUCTING MAGNETS  

E-Print Network (OSTI)

stored energy (J); jo is the superconducting matrix currentstored energy Eo(J) XBL 777-1557 Superconductor matrixmatrix current density as a function of sto~ed magnetic energy

Eberhard, P.H.

2010-01-01T23:59:59.000Z

234

The challenge of unconventional superconductivity.  

SciTech Connect

During the past few decades, several new classes of superconductors have been discovered that do not appear to be related to traditional superconductors. The source of the superconductivity of these materials is likely different from the electron-ion interactions that are at the heart of conventional superconductivity. Developing a rigorous theory for any of these classes of materials has proven to be a difficult challenge and will remain one of the major problems in physics in the decades to come.

Norman, M. R. (Materials Science Division)

2011-04-08T23:59:59.000Z

235

Hermetically sealed superconducting magnet motor  

DOE Patents (OSTI)

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.

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

1996-07-02T23:59:59.000Z

236

Hermetically sealed superconducting magnet motor  

DOE Patents (OSTI)

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.

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

1996-01-01T23:59:59.000Z

237

Process for producing clad superconductive materials  

DOE Patents (OSTI)

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.

Cass, R.B.; Ott, K.C.; Peterson, D.E.

1991-03-19T23:59:59.000Z

238

Process for producing clad superconductive materials  

DOE Patents (OSTI)

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.

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

1992-01-01T23:59:59.000Z

239

RUGGED CERAMIC WINDOW FOR RF APPLICATIONS  

Science Conference Proceedings (OSTI)

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.

MIKE NEUBAUER

2012-11-01T23:59:59.000Z

240

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

E-Print Network (OSTI)

C. Superconductivity . . . . . . . . . . . . . . . . . . .1. Heavy Fermion Superconductivity . . . . . . .Introductioon to Superconductivity, ch.1, (Dover, New York [

Gonzales, Eileen

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

RF Gun Photocathode Research at SLAC  

Science Conference Proceedings (OSTI)

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.

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

2012-05-16T23:59:59.000Z

242

bylaws of the superconducting materials committee of the minerals ...  

Science Conference Proceedings (OSTI)

of superconductivity through organized symposia and technical aspects of meetings ... macroscopic descriptions of superconductivity; physical, chemical, and.

243

Highly-textured thallium-barium-calcium-copper-oxide polycrystalline superconducting films on silver substrates  

Science Conference Proceedings (OSTI)

Thick (8 to 10 {mu}m) Ba--Ca--Cu--O films have been rf magnetron sputtered onto Ag alloy (Consil 995) substrates. The films were given a post-deposition anneal in an over pressure of Tl in order to form the superconducting phases. Annealing protocols were done which result in predominantly the 1212 and 2212 phases. The substrate orientation was varied to determine its effect on film orientation. Material properties of the films were characterized by x-ray diffraction (XRD), ion beam backscattering spectroscopy, energy dispersive x-ray analysis (EDAX), and scanning electron microscopy (SEM). Electrical characterization of the films was done using dynamic impedance (DI) at 10 kHz and rf surface resistance (R{sub s}) at 18 GHz in a TE{sub 011} fundamental mode cavity. 19 refs., 7 figs.

Arendt, P.; Elliott, N.; Cooke, D.W.; Dye, R.; Gray, E.; Hubbard, K.; Martin, J.; Reeves, G.; Brown, D.; Klapetzky, A.

1990-01-01T23:59:59.000Z

244

The role of superconductivity and cryogenics in the neutrinofactory  

DOE Green Energy (OSTI)

The proposed neutrino factory will produce a defined beam of neutrinos from the decay of muons in a storage ring[1,2,3]. The storage ring will be oriented so that the neutrinos can be detected at one or more detectors several thousand kilometers from the storage ring. This report presents an overview of the proposed neutrino factory and its subsystems that use cryogenics. Superconducting magnets will be used in the following ways in the neutrino factory; (1) the outsert solenoid for the 20 T pion capture system, (2) the decay channel where pions decay to muons, (3) the muon phase rotation system, (4) the muon cooling system, (5) focusing during the first stage of muon acceleration, (6) bending and focusing magnets in the re-circulating linac accelerator and (7) bending and focusing magnets in the muon storage ring where the neutrino beams are generated. Low temperature superconducting RF cavities will be used to accelerate the muons from about 200 MeV to 20 GeV. The muon cooling system uses liquid hydrogen absorbers at 20 K to reduce the emittance of the muon beam before it is accelerated to full energy.

Green, M.A.; Black, E.L.; Gupta, R.C.; Iarocci, M.A.; Lebedev,V.; Miller, J.R.; Palmer, R.B.; Padamsee, H.S.; Parker, B.L.; Prestemon,S.; Weggel, R.J.

2001-05-06T23:59:59.000Z

245

RF tests of an 805 MHz pillbox cavity at Lab G of Fermilab  

SciTech Connect

We report recent high power RF tests on an 805 MHz RF pillbox cavity with demountable windows for beam apertures at Lab G of Fermilab, a dedicated facility for testing of MUCOOL (muon cooling) components. The cavity is installed inside a superconducting solenoidal magnet. A 12 MW peak RF power klystron is used for the tests. The cavity has been processed both with and without magnetic field. Without magnetic field, a gradient of 34 MV/m was reached rather quickly with very low sparking rate. In a 2.5 T solenoidal field, a 16 MV/m gradient was achieved, and it had to take many weeks of conditioning. Strong multipacting effects associated with high radiation levels were measured during the processing with the magnetic field. More recently Be windows with TiN-coated surface have been installed and tested at conditions of with and without the external magnetic field. A conservative 16 MV/m gradient without magnetic field was reached quickly as planned. Less multipacting was observed during the conditioning, it indicated that the TiN-coated surface on the windows had indeed helped to reduce the secondary electron emissions significantly. A modest gradient of 16.5 MV/m was finally achieved with magnet on in solenoidal mode and the field up to 4 T. Preliminary inspection on Be windows surface found no damage at all, in comparison with Cu windows where substantial surface damage was found. Preliminary understanding of conditioning cavity in a strong magnetic field has been developed. More through window and cavity surface inspection is under way.

Li, Derun; Corlett, J.; MacGill, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian , Z.; Wu, V.; Rimmer, R.; Norem, J.; Torun, Y.

2003-05-01T23:59:59.000Z

246

High-frequency absorption of the dynamic mixed state in the surface superconductivity region  

SciTech Connect

We analyze the absorption of a high-frequency electromagnetic field in the type II superconductor Pb{sub 0.8}In{sub 0.2} in magnetic fields H{sub c2} < H < H{sub c3}. The absorption component proportional to the rate of variation of the external magnetic field is detected. We assume that this absorption component is associated with the dynamic mixed state of the superconducting shell containing 2D magnetic flux vortices (Kulik vortices). The motion of these vortices under the action of the critical current ensures the required difference between the external and internal magnetic inductions of the superconducting shell upon a change in the external magnetic field. This model correctly describes the observed behavior of absorption of rf electromagnetic radiation.

Berezin, V. A., E-mail: berezin@iptm.ru; Tulin, V. A., E-mail: tulin@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)

2013-03-15T23:59:59.000Z

247

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

SciTech Connect

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.

Ben-Zvi,I.

2008-11-17T23:59:59.000Z

248

Superconducting magnetic energy storage  

SciTech Connect

The U.S. electric utility industry transmits power to customers at a rate equivalent to only 60% of generating capacity because, on an annual basis, the demand for power is not constant. Load leveling and peak shaving units of various types are being used to increase the utilization of the base load nuclear and fossil power plants. The Los Alamos Scientific Laboratory (LASL) is developing superconducting magnetic energy storage (SMES) systems which will store and deliver electrical energy for the purpose of load leveling, peak shaving, and the stabilization of electric utility networks. This technology may prove to be an effective means of storing energy for the electric utilities because (1) it has a high efficiency (approximately 90%), (2) it may improve system stability through the fast response of the converter, and (3) there should be fewer siting restrictions than for other load leveling systems. A general SMES system and a reference design for a 10-GWh unit for load leveling are described; and the results of some recent converter tests are presented.

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

1977-01-01T23:59:59.000Z

249

Superconducting Cable Termination  

SciTech Connect

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.

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

2005-08-30T23:59:59.000Z

250

Improved superconducting magnet wire  

DOE Patents (OSTI)

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.

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

1983-08-16T23:59:59.000Z

251

Initial RF measurements of the CW normal-conducting RF injector  

Science Conference Proceedings (OSTI)

The LANL 2.5-cell, normal-conducting radio-frequency (NCRF) injector has been fabricated. We present initial results of low-power RF measurements (cavity Q, cavity field map, coupling beta, etc.) of the NCRF injector. The measured cavity Q and relative fields are found to be in good agreement with the design calculations and earlier measurements of Glidcop properties. However, the coupling beta of the ridge-loaded waveguides is found to be significantly higher than the design point. The impact of these low-power measurement results on the planned high-power RF and electron beam tests will be discussed.

Krawcyk, Frank L [Los Alamos National Laboratory; Moody, Nathan A [Los Alamos National Laboratory; Martinez, Felix A [Los Alamos National Laboratory; Nguyen, Dinh C [Los Alamos National Laboratory; Bolme, Gerald [Los Alamos National Laboratory; Young, Karen [Los Alamos National Laboratory; Toung, Lloyd [AES

2008-01-01T23:59:59.000Z

252

Nonperturbative QCD vacuum and Colour Superconductivity  

E-Print Network (OSTI)

We discuss the possibility of existence of colour superconducting state in real QCD vacuum with nonzero gluon condensate. We argue, that nonperturbative gluonic fields might play a crucial role in colour superconductivity scenario.

N. O. Agasian; B. O. Kerbikov; V. I. Shevchenko

1999-02-12T23:59:59.000Z

253

Recent Developments in High Temperature Superconductivity  

E-Print Network (OSTI)

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

Hor, P. H.

1988-09-01T23:59:59.000Z

254

Two key questions about color superconductivity  

E-Print Network (OSTI)

We pose two key questions about color superconductivity: What are the effects of the large strange quark mass, and what are the observable consequences of color superconductivity? Motivated by the first question, we study ...

Kundu, Joydip, 1977-

2004-01-01T23:59:59.000Z

255

Electrothermal simulation of superconducting nanowire avalanche photodetectors  

E-Print Network (OSTI)

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 ...

Marsili, Francesco

256

Superconductivity in the system of p electrons  

SciTech Connect

The problem of superconductivity in an electron system with partly filled sp shell is studied. The scattering amplitudes are determined and the equations of superconductivity are derived from the assumption that the Hubbard energy is the largest energy parameter.

Zaitsev, R. O., E-mail: Zaitsev_rogdai@mail.ru [Moscow State Institute of Physics and Technology (Russian Federation)

2012-10-15T23:59:59.000Z

257

Superconducting Low Voltage Direct Current (LVDC) Networks  

Science Conference Proceedings (OSTI)

A low voltage dc superconducting distribution network is a challenging future opportunity for power distribution. This report presents a scheme for a superconducting, parallel- connected, multiterminal dc transmission system.

1994-04-27T23:59:59.000Z

258

A unified theory of superconductivity  

E-Print Network (OSTI)

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

Xiuqing Huang

2008-04-10T23:59:59.000Z

259

Fast superconducting magnetic field switch  

DOE Patents (OSTI)

The superconducting magnetic switch or fast kicker magnet is employed with an 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 than 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. Magnetic switches and particularly fast kicker magnets are used in the accelerator industry to quickly deflect particle beams into and out of various transport lines, storage rings, dumps, and specifically to differentially route individual bunches of particles from a train of bunches which are injected or ejected from a given ring.

Goren, Y.; Mahale, N.K.

1995-12-31T23:59:59.000Z

260

Fast superconducting magnetic field switch  

DOE Patents (OSTI)

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.

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

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

BCS-Bose Crossover in Color Superconductivity  

E-Print Network (OSTI)

It is shown that the onset of the color superconducting phase occurs in the BCS-BE crossover region.

B. O. Kerbikov

2002-04-17T23:59:59.000Z

262

Color Superconductivity: Symmetries and Effective Lagrangians  

E-Print Network (OSTI)

I briefly review the symmetries and the associated low energy effective Lagrangian for two light flavor Color Superconductivity (2SC).

Francesco Sannino

2001-07-24T23:59:59.000Z

263

Symmetric superconducting states in thin films  

Science Conference Proceedings (OSTI)

Keywords: Ginzburg-Landau theory for superconductivity, Meissner effect, boundary value problems, calculus of variations, implicit difference scheme, maximum principle

Sheng Wang; Yisong Yang

1992-06-01T23:59:59.000Z

264

Magnetism and Superconductivity in Iron Pnictides  

Science Conference Proceedings (OSTI)

The discovery of high temperature superconductivity in iron pnictides and chalcogenides has resulted in surprising new insights into high temperature superconductivity and its relationship with magnetism. Here we provide an overview of some of what is known about these materials and in particular about the interplay of magnetism and superconductivity in them. Similarities and contrasts with cuprate superconductors are emphasized and the superconducting pairing is discussed within the framework of spin fluctuation induced pairing.

Singh, David J [ORNL

2012-01-01T23:59:59.000Z

265

Superconducting Cuprates on Catalytic Substrates - Energy ...  

Electricity Transmission Superconducting Cuprates on Catalytic Substrates Brookhaven National Laboratory. Contact BNL About This Technology Technology Marketing ...

266

Compact High-Temperature Superconducting Cable Wins ' ...  

Science Conference Proceedings (OSTI)

Compact High-Temperature Superconducting Cable Wins 'R&D 100' Award. From NIST Tech Beat: June 22, 2011. ...

2011-07-06T23:59:59.000Z

267

Superconductive articles including cerium oxide layer  

DOE Patents (OSTI)

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.

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

1991-12-31T23:59:59.000Z

268

Superconducting Multilayer Interconnect - lbl.gov  

Technique to fabricate multilayer interconnects and multiturn flux transformers for use with direct current superconducting quantum interference ...

269

Ferromagnetism and Superconductivity in Quark Matter - Color magnetic superconductivity -  

E-Print Network (OSTI)

A coexistent phase of spin polarization and color superconductivity in high-density QCD is studied at zero temperature. The axial-vector self-energy stemming from the Fock exchange term of the one-gluon-exchange interaction has a central role to cause spin polarization. As a significant feature, the Fermi surface is deformed by the axial-vector self-energy and then rotation symmetry is spontaneously broken down. The gap function results in being anisotropic in the momentum space in accordance with the deformation. It is found that spin polarization barely conflicts with color superconductivity, and almost coexists with it.

Toshitaka Tatsumi; Tomoyuki Maruyama; Eiji Nakano

2003-12-25T23:59:59.000Z

270

Superconducting wire with improved strain characteristics  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

271

Superconducting wire with improved strain characteristics  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

272

Superconducting wire with improved strain characteristics  

DOE Patents (OSTI)

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.

Luhman, T.; Klamut, C.J.; Suenaga, M.; Welch, D.

1979-12-19T23:59:59.000Z

273

CLIC RF High Power Production Testing Program  

SciTech Connect

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

Syratchev, I.; Riddone, G.; /CERN; Tantawi, S.G.; /SLAC

2011-11-02T23:59:59.000Z

274

Accelerator and rf system development for NLC  

Science Conference Proceedings (OSTI)

An experimental station for an X-band Next Linear Collider has been constructed at SLAC. This station consists of a klystron and modulator, a low-loss waveguide system for rf power distribution, a SLED II pulse-compression and peak-power multiplication system, acceleration sections and beam-line components (gun, prebuncher, preaccelerator, focussing elements and spectrometer). An extensive program of experiments to evaluate the performance of all components is underway. The station is described in detail in this paper, and results to date are presented.

Vlieks, A.E.; Callin, R.; Deruyter, H. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)] [and others

1993-04-01T23:59:59.000Z

275

Electronic structure of superconductivity refined  

NLE Websites -- All DOE Office Websites (Extended Search)

Electronic structure of superconductivity refined 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 physics and new materials. 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 physics and new materials.

276

Ramesh Gupta | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Ramesh Gupta Ramesh Gupta Ramesh Gupta has always been a leader in the world of superconducting magnets, which are essential to great modern accelerators such as the Relativistic Heavy Ion Collider at BNL, and the Large Hadron Collider at CERN, Switzerland. For the past decade, Lab researchers have been exploring the use of new materials that become superconducting at higher temperatures. Gupta, head of the High Temperature Superconductor (HTS) Research and Development Group in the Superconducting Magnet Division, is among those exploring avenues for HTS magnets that are energy efficient and have magnetic fields that are a million times stronger than the Earth's. These new magnets could revolutionize use in future accelerators, play a key role in energy efficiency and storage, and make possible new

277

Strain tolerant microfilamentary superconducting wire  

DOE Patents (OSTI)

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.

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)

1993-02-23T23:59:59.000Z

278

Active high-power RF switch and pulse compression system  

DOE Patents (OSTI)

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.

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

1998-01-01T23:59:59.000Z

279

Available Technologies: High Efficiency Spiral RF-Induction ...  

The spiral antennas efficient use of source geometry also ... Neutron and high energy gamma ... A typical RF-induction plasma generator with a ...

280

Influence of Substrate Temperature and RF Power on the Formation ...  

Science Conference Proceedings (OSTI)

Presentation Title, Influence of Substrate Temperature and RF Power on the Formation of ZnO Nanorods for Solar Driven Hydrogen Production. Author(s) ...

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

High power RF test of an 805 MHz RF cavity for a muon cooling channel  

SciTech Connect

We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

2002-05-30T23:59:59.000Z

282

Dual control active superconductive devices  

Science Conference Proceedings (OSTI)

A dual control active superconducting device is described comprising; (a) a first device having a first main conduction channel formed of a film of superconductor on a substrate, an active weak link region interposed in the first main conduction channel, the active weak link region composed of a plurality of links formed of a thin film of superconductor separated by non-superconductive voids, the thickness and lateral dimensions of the links selected such that magnetic flux can propagate across the weak link region when it is superconducting, and a first control line having a portion adjacent to the active weak link region of the first main conduction channel such that current in the first control line will impose a magnetic flux on the weak link region; (b) a second superconducting device having a second main conduction channel formed of a film of superconductor on a substrate, an active weak link region interposed in the second main conduction channel, the active weak link region composed of at least one link formed of a thin film of superconductor separated by non-superconductive voids, the thickness and lateral dimensions of the links selected such that magnetic flux can propagate across the weak link region when it is superconducting, and a second control line having a portion adjacent to the active weak link region such that current in the second control line will impose a magnetic flux on the weak link region in the second main conduction channel; (c) an internal control line electrically connected to receive the current passed through the first main conduction channel and having a portion adjacent to the active weak link region of the second main conduction channel such that a current in the internal control line will impose a magnetic flux on the weak link region; and (d) electrical connectors connected to provide input current to the first and second main conduction channels and to conduct the output current.

Martens, J.S.; Beyer, J.B.; Nordman, J.E.; Hohenwarter, G.K.G.

1993-07-20T23:59:59.000Z

283

A Physical Picture of Superconductivity  

E-Print Network (OSTI)

A universal mechanism of superconductivity applicable to “low temperature” and “high temperature ” superconductors is proposed in this paper. With this model of mechanism experimental facts of superconductors can be qualitatively explained. A function is introduced to describe the average separation distance between vibrating lattice atoms, which is crucial for the transition from normal to superconductive state. However, the most attractive and exciting conclusion that can be derived from this physical picture, is that given atoms of other element be successfully sandwiched between ferromagnetic atoms one by one, a superconductor constructed this way is most likely to have a very high transition temperature.

W. Z. Shangguan; T. C. Au-yeung

2000-01-01T23:59:59.000Z

284

Freely oriented portable superconducting magnet  

SciTech Connect

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.

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

2010-01-12T23:59:59.000Z

285

Low-power/low-voltage RF microsystems for wireless sensors networks  

Science Conference Proceedings (OSTI)

This paper presents radio-frequency (RF) microsystems (MSTs) composed by low-power devices for use in wireless sensors networks (WSNs). The RF CMOS transceiver is the main electronic system and its power consumption is a critical issue. Two RF CMOS transceivers ... Keywords: RF CMOS transceiver, RF microsystems, Wireless sensors networks

J. P. Carmo; J. H. Correia

2009-12-01T23:59:59.000Z

286

Recent advances in RF power generation  

SciTech Connect

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

Tallerico, P.J.

1990-01-01T23:59:59.000Z

287

Extremely high frequency RF effects on electronics.  

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

288

Fermilab Tevatron high level rf accelerating systems  

SciTech Connect

Eight tuned rf cavities have been installed and operated in the F0 straight section of the Tevatron. Their mechanical placement along the beam line enables them to be operated for colliding beams as two independent groups of four cavities, group 1-4 accelerating antiprotons and group 5-8 accelerating protons. The only difference is that the spacing between cavities 4 and 5 was increased to stay clear of the F0 colliding point. The cavities can easily be rephased by switching cables in a low-level distribution system (fan-out) so that the full accelerating capability of all eight cavities can be used during fixed target operations. Likewise, the cables from capacitive probes on each cavity gap can be switched to proper lengths and summed in a fan-back system to give an rf signal representing the amplitude and phase as ''seen by the beam,'' separately for protons and antiprotons. Such signals have been used to phase lock the Tevatron to the Main Ring for synchronous transfer.

Kerns, Q.; Kerns, C.; Miller, H.; Tawser, S.; Reid, J.; Webber, R.; Wildman, D.

1985-06-01T23:59:59.000Z

289

Free-standing oxide superconducting articles  

DOE Patents (OSTI)

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.

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

1993-12-14T23:59:59.000Z

290

Meissner superconductivity in itinerant ferromagnets  

E-Print Network (OSTI)

Recent results about the coexistence of ferromagnetism and unconventional superconductivity with spin-triplet Cooper pairing are reviewed on the basis of the quasi-phenomenological Ginzburg-Landau theory. The superconductivity in the mixed phase of coexistence of ferromagnetism and unconventional superconductivity is triggered by the spontaneous magnetization. The mixed phase is stable whereas the other superconducting phases that usually exist in unconventional superconductors are either unstable or metastable at relatively low temperatures in a quite narrow domain of the phase diagram and the stability properties are determined by the particular values of Landau parameters. The phase transitions from the normal phase to the phase of coexistence is of first order while the phase transition from the ferromagnetic phase to the coexistence phase can be either of first or second order depending on the concrete substance. The Cooper pair and crystal anisotropy are relevant to a more precise outline of the phase diagram shape and reduce the degeneration of the ground states of the system. The results are discussed in view of application to itinerant ferromagnetic compounds as UGe2, ZrZn2, URhGe. 1

D. V. Shopova; D. I. Uzunov

2005-01-01T23:59:59.000Z

291

Superconducting flux flow digital circuits  

DOE Patents (OSTI)

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.

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

1995-02-14T23:59:59.000Z

292

Superconducting flux flow digital circuits  

DOE Patents (OSTI)

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.

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

1995-01-01T23:59:59.000Z

293

Booster Synchrotron RF System Upgrade for SPEAR3  

Science Conference Proceedings (OSTI)

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.

Park, Sanghyun; /SLAC; Corbett, Jeff; /SLAC

2012-07-06T23:59:59.000Z

294

Self-homodyne RF-optical microdisk receiver  

E-Print Network (OSTI)

modulation with optical transfer function (Po VRF 2 ) Self-homodyne RF-photonic receiver f ip Nonlinear and nonlinear modulation Transmittedoptical power t Wavelength t t Linear (Po VRF) Nonlinear (Po VRF 2) VRF ),,,,,( , 0 2 0 2 2 tPQGf dV Pd N EinoV VRF RF == = Microdisk optical mixer (laser= res) GV : voltage gain Q

Levi, Anthony F. J.

295

ITO Thin Films by RF Sputtering for Ethanol Sensing  

Science Conference Proceedings (OSTI)

The sensor for detection of ethanol vapours using RF sputter deposited ITO thin film on glass and Si substrates is reported. The principle of operation is the change of resistance of ITO film on exposure to ethanol vapours. The films were annealed at ... Keywords: Indium Tin Oxide, RF sputtering, ethanol sensor

Sudhir Chandra; H. J. Pandya; A. L. Vyas

2010-07-01T23:59:59.000Z

296

RF cavity using liquid dielectric for tuning and cooling  

SciTech Connect

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.

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

2012-04-17T23:59:59.000Z

297

A high-power L-band RF window  

E-Print Network (OSTI)

June. 2001. [3] "700 MHz Window R&D at LBNL", R. Rimmer et.Testing of PEP-II RF Cavity Windows", M. Neubauer et. al. ,A HIGH-POWER L-BAND RF WINDOW* R.A. Rimmer † , G. Koehler,

2001-01-01T23:59:59.000Z

298

RF-MEMS capacitive switches with high reliability  

DOE Patents (OSTI)

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.

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

2013-09-03T23:59:59.000Z

299

RF Power Degradation of GaN High Electron Mobility Transistors  

E-Print Network (OSTI)

We have developed a versatile methodology to systematically investigate the RF reliability of GaN High-Electron Mobility Transistors. Our technique utilizes RF and DC figures of merit to diagnose the degradation of RF ...

Joh, Jungwoo

300

Progress on the RF Coupling Coil Module Design for the MICE Channel  

E-Print Network (OSTI)

Spallation Neutron Source (SNS) type ceramic RF windows arecouplers together with the SNS-type ceramic RF window. Ahigh power tested now at the SNS RF test lab. Cavity length

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Design Parameters and Commissioning of Vertical Inserts Used for Testing the XFEL Superconducting Cavities  

E-Print Network (OSTI)

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.

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

2013-06-26T23:59:59.000Z

302

Proposal for high pressure RF cavity test in the MTA  

DOE Green Energy (OSTI)

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

Yonehara, K.; /Fermilab

2010-09-01T23:59:59.000Z

303

Cold Test Measurements on the GTF Prototype RF Gun  

Science Conference Proceedings (OSTI)

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.

Gierman, S.M.

2010-12-03T23:59:59.000Z

304

Bifurcation analysis for phase transitions in superconducting rings with nonuniform thickness  

Science Conference Proceedings (OSTI)

Keywords: Ginzburg-Landau functional, Little-Parks experiment, superconducting rings, superconductivity

Jorge Berger; Jacob Rubinstein

1998-02-01T23:59:59.000Z

305

e Lens Solenoid | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Lens Solenoid Electron Lens Solenoid To increase the proton beam luminosity in RHIC, an electron lens (e-lens) magnet system with two superconducting solenoids is being built at Brookhaven National Laboratory. Initial Design of 200 mm, 6T Superconducting Solenoid for e-lens (pdf), R. Gupta, 3/30/10 Iterated Design of 200 mm, 6T Superconducting Solenoid for e-lens (pdf), R. Gupta, 4/6/10 Corrector Designs for Superconducting Solenoid for e-lens (pdf), R. Gupta, 4/14/10 eLens Layout (pdf), P. Kovach, 5/25/10 eLens Main Solenoid (pdf), A. Marone, 5/25/10 Optimization in Corrector Design for Superconducting Solenoid for e-Lens (pdf), R. Gupta, 6/15/10 Main Solenoid Axial Force Retention (pdf), A. Marone 8/24/10 Superconducting Solenoid for e-lens with Fringe Field Coil (pdf), R.

306

Tunable high-q superconducting notch filter  

DOE Patents (OSTI)

A superconducting notch filter is made of three substrates disposed in a cryogenic environment. A superconducting material is disposed on one substrate in a pattern of a circle and an annular ring connected together. The second substrate has a corresponding pattern to form a parallel plate capacitor and the second substrate has the circle and annular ring connected by a superconducting spiral that forms an inductor. The third substrate has a superconducting spiral that is placed parallel to the first superconducting spiral to form a transformer. Relative motion of the first substrate with respect to the second is effected from outside the cryogenic environment to vary the capacitance and hence the frequency of the resonant circuit formed by the superconducting devices.

Pang, C.S.; Falco, C.M.; Kampwirth, R.T.; Schuller, I.K.

1979-11-29T23:59:59.000Z

307

Nanofabrication using focused ion beam  

E-Print Network (OSTI)

Deposition 47 3.2.3 Photolithography 48 3.2.4 Al Dissolution, Advanced Scanning Electron Microscope Specimen Preparation and Other Methods 50 3.2.4.1 Al Dissolution 50 3.2.4.2 Advanced Scanning Electron Microscope Specimen Preparation 51 3... . Measurements performed included in-situ resistometric measurements, which provided milled depth information by monitoring the resistance change of a metal track while ion milling it. The reproducibly of this method was confirmed by repeating experiments...

Latif, Adnan

308

The Molecular Foundry - Nanofabrication - Publications  

NLE Websites -- All DOE Office Websites (Extended Search)

and Pattern Stabilization in A Solution-Processed Subphthalocyanine Film," ACS Nano, 4, 5, 2627 (2010). pdf X. Liang, V. Giacometti, A. Ismach, B. D. Harteneck, D. L....

309

The Molecular Foundry - Nanofabrication - Publications  

NLE Websites -- All DOE Office Websites (Extended Search)

10 nm half-pitch by atomic layer deposition enabled spacer double patterning," Nanotechnology 24 105303 (2013). DOI:10.10880957-44842410105303 pdf A. Polyakov, C. Senft,...

310

Composite for superconducting metal oxide  

DOE Patents (OSTI)

A principal objective of the invention is to provide a new superconducting composite which has a greatly improved ductility and fracture resistance to assist in the fabrication and processing of superconductors and to provide long service life. A principal objective of the present invention is to provide a composite superconductor comprising a continuous superconductor phase and a minor amount of silver present as a discontinuous phase.

Singh, Jitendra P.; Shi, Donglu; Capone, D.W. II; Dusek, J.T.

1988-12-23T23:59:59.000Z

311

Processing method for superconducting ceramics  

DOE Patents (OSTI)

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.

Bloom, I.D.; Poeppel, R.B.; Flandermeyer, B.K.

1990-05-07T23:59:59.000Z

312

Ten questions and answers about superconductivity  

E-Print Network (OSTI)

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

Tian De Cao

2010-06-29T23:59:59.000Z

313

Superconducting thin films on potassium tantalate substrates  

DOE Patents (OSTI)

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.

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

1992-01-01T23:59:59.000Z

314

Dual control active superconductive devices  

DOE Patents (OSTI)

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.

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

1993-07-20T23:59:59.000Z

315

Plasma rotation and rf heating in DIII-D  

SciTech Connect

In a variety of discharge conditions on DIII-D it is observed that rf electron heating reduces the toroidal rotation speed and core ion temperature. The rf heating can be with either fast wave or electron cyclotron heating and this effect is insensitive to the details of the launched toroidal wavenumber spectrum. To date all target discharges have rotation first established with co-directed neutral beam injection. A possible cause is enhanced ion momentum and thermal diffusivity due to electron heating effectively creating greater anomalous viscosity. Another is that a counter directed toroidal force is applied to the bulk plasma via rf driven radial current.

deGrassie, J.S.; Baker, D.R.; Burrell, K.H. [General Atomics, San Diego, CA (United States)] [and others

1999-05-01T23:59:59.000Z

316

Superconductivity with Stripes | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2000 | 1998 | Subscribe to APS Science Highlights rss feed Superconductivity with Stripes October 18, 2013 Bookmark and Share The interplay between stripe order,...

317

Superconductivity Technology Center - Los Alamos National Lab ...  

Researchers at the facility conduct research and development on processes for fabrication of high temperature superconducting tapes, measurement of the physical and ...

318

Center for Emergent Superconductivity 2013 Fall Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Center for Emergent Superconductivity (CES) 2013 Fall Workshop Homepage Registration pulldown Talks pulldown CES Workshop Talks CES Jr. Research Talks Programs pulldown Contact Us...

319

Center for Emergent Superconductivity 2013 Fall Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

main gate, please inform the guard you are attending the Center for Emergent Superconductivity 2013 Fall Workshop workshop. You may be requested to check in at the security...

320

High Temperature Interfacial Superconductivity - Energy Innovation ...  

Cuprate superconductors exhibit relatively high transition temperatures, but their unit cells are complex and large. Localizing a superconducting layer to a small ...

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Publications | Ramesh Gupta | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

for muon collider" (pdf), R. Gupta, et al., 2010 Applied Superconductivity Conference, Washington, DC, August 2010. Slides from the talk (pdf) "Second Generation HTS Quadrupole...

322

ORNL superconducting wire yields unprecedented performance |...  

NLE Websites -- All DOE Office Websites (Extended Search)

ORNL | News | News Releases | 2013 SHARE Media Contact: Morgan McCorkle Communications 865.574.7308 ORNL superconducting wire yields unprecedented performance This figure shows the...

323

Two key questions about color superconductivity.  

E-Print Network (OSTI)

??We pose two key questions about color superconductivity: What are the effects of the large strange quark mass, and what are the observable consequences of… (more)

Kundu, Joydip, 1977-

2004-01-01T23:59:59.000Z

324

Digital Cable Goes Quantum: NIST Debuts Superconducting ...  

Science Conference Proceedings (OSTI)

... The setup resembles a miniature version of a cable-television transmission line, but with some powerful added features, including superconducting ...

2012-06-08T23:59:59.000Z

325

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

SciTech Connect

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.

Guo, Jiquan; /SLAC

2009-03-20T23:59:59.000Z

326

A Superconducting transformer system for high current cable testing  

E-Print Network (OSTI)

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

Godeke, A.

2010-01-01T23:59:59.000Z

327

Magnetism and superconductivity observed to exist in harmony  

NLE Websites -- All DOE Office Websites (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,...

328

Commissioning of the superconducting ECR ion source VENUS  

E-Print Network (OSTI)

COMMISSIONING OF THE SUPERCONDUCTING ECR ION SOURCE VENUS *paper describes the ongoing commissioning. Initial resultscoils [2]. During commissioning of the superconducting

Leitner, Daniela; Abbott, Steve R.; Dwinell, Roger D.; Leitner, Matthaeus; Taylor, Clyde; Lyneis, Claude M.

2003-01-01T23:59:59.000Z

329

Quantum transport and field-induced superconductivity in carbon nanotubes.  

E-Print Network (OSTI)

?? For my thesis, I conducted experiments to investigate superconductivity and superconducting proximity effect in carbon nanotubes. The measurements are carried out on carbon nanotube… (more)

Yang, Yanfei

2010-01-01T23:59:59.000Z

330

Handbook for Gas Filled RF Cavity Aficionados'  

DOE Green Energy (OSTI)

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

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

2009-05-01T23:59:59.000Z

331

RF Micro Devices Inc RFMD | Open Energy Information  

Open Energy Info (EERE)

RF Micro Devices Inc RFMD RF Micro Devices Inc RFMD Jump to: navigation, search Name RF Micro Devices, Inc. (RFMD) Place 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. Coordinates 44.576059°, -72.294016° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.576059,"lon":-72.294016,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

332

Efficiency enhancement techniques for RF and millimeter wave power amplifiers  

E-Print Network (OSTI)

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

Ogunnika, Olumuyiwa Temitope, 1978-

2012-01-01T23:59:59.000Z

333

An improved RF cavity search for halo axions  

E-Print Network (OSTI)

The axion is a hypothetical elementary particle and cold dark matter candidate. In this RF cavity experiment, halo axions entering a resonant cavity immersed in a static magnetic field convert into microwave photons, with ...

Yu, D. B. (Daniel Byungyoon), 1976-

2004-01-01T23:59:59.000Z

334

High Frequency High Power RF Generation using a Relativistic...  

NLE Websites -- All DOE Office Websites (Extended Search)

FREQUENCY HIGH POWER RF GENERATION USING A RELATIVISTIC ELECTRON BEAM C. Jing , S. Antipov, P. Schoessow, and A. Kanareykin, Euclid Techlabs LLC, Solon, OH-44139 J.G. Power, M....

335

A Test and Diagnosis Methodology for RF Transceivers  

Science Conference Proceedings (OSTI)

This paper proposes an RF test and diagnosis methodology based on digital DFT structure and builtin DSP function of a SoC Chip. Constellation variation plots are proposed to identify the faulty component. Furthermore, linear interpolation is used to ...

Hung-kai Chen; Chauchin Su

2007-10-01T23:59:59.000Z

336

Test estructural i predictiu per a circuits RF CMOS.  

E-Print Network (OSTI)

??En aquesta tesi s'ha desenvolupat una tècnica de test que permet testar un LNA i un mesclador, situats en el capçal RF d'un receptor CMOS,… (more)

Suenaga Portugués, Kay

2008-01-01T23:59:59.000Z

337

Hom dampers for ALS storage ring RF cavities  

E-Print Network (OSTI)

of the HOM dampers on ALS rf cavities was an immediatesuccess. Now, the ALS storage ring can operate with the 312The cross-section of the ALS third harmonic cavity with two

2003-01-01T23:59:59.000Z

338

Electrodeless lighting RF power source development. Final report  

SciTech Connect

An efficient, solid state RF power source has been developed on this NICE project for exciting low power electrodeless lamp bulbs. This project takes full advantage of concurrent advances in electrodeless lamp technology. Electrodeless lamp lighting systems utilizing the sulfur based bulb type developed by Fusion Lighting, Inc., is an emerging technology which is based on generating light in a confined plasma created and sustained by RF excitation. The bulb for such a lamp is filled with a particular element and inert gas at low pressure when cold. RF power from the RF source creates a plasma within the bulb which reaches temperatures approaching those of high pressure discharge lamp plasmas. At these temperatures the plasma radiates substantial visible light with a spectrum similar to sunlight.

NONE

1996-08-30T23:59:59.000Z

339

BN/Graphene/BN Transistors for RF Applications  

E-Print Network (OSTI)

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

Taychatanapat, Thiti

340

Recent Progress of RF Cavity Study at Mucool Test Area  

DOE Green Energy (OSTI)

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.

Yonehara, Katsuya; /Fermilab

2011-12-02T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Channel engineering of SOI MOSFETs for RF applications  

E-Print Network (OSTI)

Channel engineering of SOI MOSFETs is explored by altering ion implantation without adding any new fabrication steps to the standard CMOS process. The effects of implantation on characteristics important for RF applications, ...

Keast, Craig L.

342

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

DOE Patents (OSTI)

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.

McEwan, T.E.

1997-05-13T23:59:59.000Z

343

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

DOE Patents (OSTI)

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.

McEwan, Thomas E. (Livermore, CA)

1997-01-01T23:59:59.000Z

344

RF and Beam Diagnostic Instrumentation at the Advanced Photon Source (APS) Linear Accelerator (Linac)  

E-Print Network (OSTI)

RF and Beam Diagnostic Instrumentation at the Advanced Photon Source (APS) Linear Accelerator (Linac)

Grelick, A E; Arnold, N; White, M

1996-01-01T23:59:59.000Z

345

Rf power systems for the national synchrotron light source  

SciTech Connect

The booster synchrotron and the two storage rings at the NSLS are provided with rf power systems of 3 kW, 50 kW, and 500 kW nominal output power, all at 53 MHz. This power is supplied by grounded grid tetrode amplifiers designed for television broadcast service. These amplifiers and associated power supplies, control and interlock systems, rf controls, and computer interface are described.

Dickinson, T.; Rheaume, R.H.

1981-01-01T23:59:59.000Z

346

The superconductivity of some intermetallic compounds  

Science Conference Proceedings (OSTI)

The W-Os, Re-W, Re-Mo, Re-Hf, and Mo-Hf binary systems were investigated for superconductivity down to 1°K. Several new superconducting regions were found with the most significant occurring in the primary and terminal solid-solution alloys. The ...

R. D. Blaugher; A. Taylor; J. K. Hulm

1962-01-01T23:59:59.000Z

347

Design Concepts for a Superconducting Cable  

Science Conference Proceedings (OSTI)

Superconducting cables carry higher currents and, depending upon the design, can experience substantially lower transmission losses than conventional cables. This report discusses previous approaches to designing superconducting cables, describes the technical issues that must be considered when designing a high-temperature superconductor (HTS) cable, and presents several design concepts for an HTS cable.

1994-09-28T23:59:59.000Z

348

Correlational analysis of superconducting mixed copper oxides  

Science Conference Proceedings (OSTI)

A unifying structural scheme of all layered superconducting cuprates is proposed. The paper is a review based on a three level correlational analysis of the behaviour of one compound, of a homologous series and a third interseries analysis, revealing ... Keywords: correlational analysis, homologous series, layered cuprates, superconductivity

Cristina Zarioiu; V. G. Lascu; Lidia Petrova; Anca Novac

2008-06-01T23:59:59.000Z

349

Three-cell traveling wave superconducting test structure  

Science Conference Proceedings (OSTI)

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.

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

2011-03-01T23:59:59.000Z

350

Stripes and superconductivity in cuprate superconductors  

E-Print Network (OSTI)

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

J. M. Tranquada

2005-01-01T23:59:59.000Z

351

STRIPES AND SUPERCONDUCTIVITY IN CUPRATE SUPERCONDUCTORS  

SciTech Connect

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

TRANQUADA, J.M.

2005-08-22T23:59:59.000Z

352

Applications of superconductivity in electric power systems  

DOE Green Energy (OSTI)

Major applications of superconductivity to power systems are considered. The state of the art of materials and refrigeration developments that are necessary for these applications is reviewed. Specific applications including superconducting cables for power transmission and superconducting magnetics for MHD generators, for energy storage, and for magnetically-confined fusion power generation are discussed in terms of their advantages and the progress being made toward introducing the various devices into real situations. It is concluded that the feasibility of superconducting devices is assured, and that, although their performance, reliability, and cost effectiveness for use in power generation, transmission, and storage remain to be proven, it is reasonable to expect that superconductivity can make it in the real world. (LCL)

Keller, W.E.

1976-01-01T23:59:59.000Z

353

Free-standing oxide superconducting articles  

DOE Patents (OSTI)

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).

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

1993-01-01T23:59:59.000Z

354

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

SciTech Connect

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.

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.

2008-07-07T23:59:59.000Z

355

Microelectronic superconducting crossover and coil  

DOE Patents (OSTI)

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.

Wellstood, Frederick C. (Berkeley, CA); Kingston, John J. (Oakland, CA); Clarke, John (Berkeley, CA)

1994-01-01T23:59:59.000Z

356

Microelectronic superconducting crossover and coil  

DOE Patents (OSTI)

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.

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

1994-03-01T23:59:59.000Z

357

Superconducting coil and method of stress management in a superconducting coil  

DOE Patents (OSTI)

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).

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

1999-01-01T23:59:59.000Z

358

RF-Plasma Source Commissioning in Indian Negative Ion Facility  

Science Conference Proceedings (OSTI)

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.

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

2011-09-26T23:59:59.000Z

359

Reassessment of Superconducting Magnetic Energy Storage (SMES) Transmission System Benefits  

Science Conference Proceedings (OSTI)

This report reassesses the benefits of superconducting magnetic energy storage (SMES) for enhancing transmission system performance.

2002-03-21T23:59:59.000Z

360

Method for making mirrored surfaces comprising superconducting material  

DOE Patents (OSTI)

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.

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

1989-12-12T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

High Temperature Superconducting Underground Cable  

SciTech Connect

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

Farrell, Roger, A.

2010-02-28T23:59:59.000Z

362

Fabrication of superconducting nanowire single proton detectors  

E-Print Network (OSTI)

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

Yang, Joel K. (Joel Kwang wei)

2005-01-01T23:59:59.000Z

363

Microsoft PowerPoint - rf_5year_review  

NLE Websites -- All DOE Office Websites (Extended Search)

RF Research Program RF Research Program DOE Review of C-Mod Five-Year Proposal May 13-14, 2003 MIT PSFC Presented by Steve J.Wukitch Outline: 1. Overview of the RF Program 2. Five-year plan Overview of the RF Program AT: validate steady state operation with target parameters β N = 3, I non = 100%, I BS ~ 70%, H 89 ~ 2.5, for t pulse > t L/R . BPX: demonstrate the viability of high performance plasmas, B T = 8T, I p = 2 MA, P = 6 MW, H 89 ≥ 2, Z eff < 1.5. B T = 5.4T, I p = 1.4 MA, P = 6 MW, H 89 = 2 (ITER demo) Exclusively use RF power for auxiliary heating and current drive. variable variable fixed Phase 2 x 4 Strap 4 Strap 2 x 2 Strap Antenna 4 MW 40-80 MHz J-port 2 x 4 MW 2 x 2 MW Power 40-80 MHz ~ 80 MHz Frequency E & J-port D & E-port 2005-2008 2002-2005 4.6 GHz 4.6 GHz Frequency 16 x 250 kW

364

RF Power Upgrade for CEBAF at Jefferson Laboratory  

Science Conference Proceedings (OSTI)

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.

Andrew Kimber,Richard Nelson

2011-03-01T23:59:59.000Z

365

A 12 GHz RF Power Source for the CLIC Study  

SciTech Connect

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.

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

2012-07-03T23:59:59.000Z

366

rf improvements for Spallation Neutron Source H ion source  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering 38 mA H beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride AlN plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. 2010 American Institute of Physics.

Kang, Yoon W [ORNL; Fuja, Raymond E [ORNL; Goulding, Richard Howell [ORNL; Hardek, Thomas W [ORNL; Lee, Sung-Woo [ORNL; McCarthy, Mike [ORNL; Piller, Chip [ORNL; Shin, Ki [ORNL; Stockli, Martin P [ORNL; Welton, Robert F [ORNL

2010-01-01T23:59:59.000Z

367

An improved oxygen diffusion model to explain the effect of low-temperature baking on high field losses in niobium superconducting cavities  

SciTech Connect

Radio-frequency (RF) superconducting cavities made of high purity niobium are widely used to accelerate charged particle beams in particle accelerators. The major limitation to achieve RF field values approaching the theoretical limit for niobium is represented by ''anomalous'' losses which degrade the quality factor of the cavities starting at peak surface magnetic fields of about 100 mT, in absence of field emission. These high field losses are often referred to as ''Q-drop''. It has been observed that the Q-drop is drastically reduced by baking the cavities at 120 C for about 48 h under ultrahigh vacuum. An improved oxygen diffusion model for the niobium-oxide system is proposed to explain the benefit of the low-temperature baking on the Q-drop in niobium superconducting rf cavities. The model shows that baking at 120 C for 48 h allows oxygen to diffuse away from the surface, and therefore increasing the lower critical field towards the value for pure niobium.

Gianluigi Ciovati

2005-09-15T23:59:59.000Z

368

CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURE NORMAL-STATE HEAT CAPACITY OF TUNGSTEN  

E-Print Network (OSTI)

y CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURECritical Field for Superconductivity and Low-Temperaturemagnetic field for superconductivity In tungsten from 5.5 to

Triplett, B.B.

2008-01-01T23:59:59.000Z

369

Some aspects of color superconductivity: an introduction  

E-Print Network (OSTI)

A pedagogical introduction to color superconductivity in the weak coupling limit is given. The focus is on the basic tools of thermal field theory necessary to compute observables of color superconductivity. The rich symmetry structure and symmetry breaking patterns are analyzed on the basis of the Anderson-Higgs mechanism. Some techniques can also be applied for computing neutrino processes in compact stars. As an example, we show how to obtain the neutrino emissivity for Urca processes in neutron stars by computing the polarization tensor of the W-boson. We also illustrate how a spin-1 color superconducting phase generates an anisotropic neutrino emissions in compact stars.

Qun Wang

2009-12-13T23:59:59.000Z

370

Superconductivity  

Science Conference Proceedings (OSTI)

Add to Cart, Image, Click on Title to view details, Member (Student) Price, Non- member Price. Available at wiley.com, Advanced Materials for Energy Conversion ...

371

Cooling Strings of Superconducting Devices below 2 K the Helium II Bayonet Heat Exchanger  

E-Print Network (OSTI)

High-energy particle accelerators and colliders contain long strings of superconducting devices - acceleration RF cavities and magnets - operating at high field, which may require cooling in helium II below 2 K. In order to maintain adequate operating conditions, the applied or generated heat loads must be extracted and transported with minimum temperature difference. Conventional cooling schemes based on conductive or convective heat transport in pressurized helium II very soon reach their intrinsic limits of thermal impedance over extended lengths. We present the concept of helium II bayonet heat exchanger, which has been developed at CERN for the magnet cooling scheme of the Large Hadron Collider (LHC), and describe its specific advantages as a slim, quasi-isothermal heat sink. Experimental results obtained on several test set-ups, and a prototype magnet string have permitted to validate its performance and sizing rules, for transporting linear heat loads in the W.m-1 range over distances of several tens o...

Lebrun, P; Tavian, L; Van Weelderen, R

1998-01-01T23:59:59.000Z

372

A computer program for HVDC converter station RF noise calculations  

SciTech Connect

HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

1994-04-01T23:59:59.000Z

373

RHIC Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Project RHIC Project The Superconducting Magnet Division supplied 1740 magnetic elements, in 888 cryostats, for the RHIC facility at BNL. Of these, 780 magnetic elements were manufactured by Northrop-Grumman (Bethpage, NY) and 360 were made by Everson Electric (Bethlehem, PA). The magnets made in industry used designs developed at BNL. The first cooldown of the magnets for the RHIC engineering run was in 1999. Since then, the magnets have operated very reliably. arc dipole coil and yoke Arc dipole coil and yoke, with magnetic flux lines The magnets provide modest field (3.45 Teslas in the arc dipoles) in a cost-effective design. Key features in the principal bending and focusing magnets include the use of NbTi Rutherford cable, a single-layer coil, and cold iron as both yoke and collar. The magnets operate in forced-flow

374

Superconducting Magnet Division | Brookhaven National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Magnet Division Superconducting Magnet Division Home Production & Testing LHC Dipole Acceptance APUL Schedule (pdf) Projects Main Projects HTS Magnet Program High Field Magnet R&D Linear Collider Final Focus e Lens Solenoid Correctors for J-PARC Correctors for SuperKEKB IR Magnets LARP APUL Past Projects BEPC-II IR Quadrupoles Bio-Med Variable Field MRI GSI Rapid Cycling Magnets Helical Magnets HERA upgrade LHC IR Dipoles RHIC Publications Search Publications Selected Cryogenic Data Notebook Proceedings of the 1968 Summer Study on Superconducting Devices and Accelerators Meetings & Workshops Safety Environmental, Safety & Health ES&H Documents Lockout-Tagout Personnel Staff Pages Ramesh Gupta Brett Parker Peter Wanderer Pe ter Wanderer, head of Brookhaven's Superconducting Magnet Division,

375

New Science with the APS Superconducting Undulator  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed New Science with the APS Superconducting Undulator JULY 24, 2013 Bookmark and Share The Nature...

376

MAGNETIC DESIGN OF A SUPERCONDUCTING AGS SNAKE*  

NLE Websites -- All DOE Office Websites (Extended Search)

a partial helical snake for polarized proton acceleration in the AGS. It will be a 3 Tesla superconducting magnet having a magnetic length of 1.9 meter. AGS needs only one...

377

Helical Magnets Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC, the basic construction unit is a superconducting dipole magnet producing a four tesla dipole field that rotates through 360 degrees in a length of 2.4 meters. The magnets...

378

Bipolaron Model of Superconductivity in Chalcogenide Glasses  

E-Print Network (OSTI)

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

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

2010-10-25T23:59:59.000Z

379

Magnetism and superconductivity of heavy fermion matter  

E-Print Network (OSTI)

The interplay of magnetism and unconventional superconductivity (d singlet wave or p triplet wave) in strongly correlated electronic system (SCES) is discussed with recent examples found in heavy fermion compounds. A short presentation is given on the formation of the heavy quasiparticle with the two sources of a local and intersite enhancement for the effective mass. Two cases of the coexistence or repulsion of antiferromagnetism and superconductivity are given with CeIn3 and CeCoIn5. A spectacular example is the emergence of superconductivity in relatively strong itinerant ferromagnets UGe2 and URhGe. The impact of heavy fermion matter among other SCES as organic conductor or high TC oxide is briefly pointed out. Key words: heavy fermion, superconductivity, antiferromagnetism, ferromagnetism

J. Flouquet A; G. Knebel A; D. Braithwaite A; D. Aoki B; J. P. Brison C; F. Hardy A; A. Huxley A; S. Raymond A; B. Salce A; I. Sheikin D

2005-01-01T23:59:59.000Z

380

Publications | Ramesh Gupta | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Symposium on Superconductivity (ISS2012) in Tokyo, Japan, December 3-5, 2012. HTS Magnet R&D at BNL (pdf), LTHFSW2012 at Napa, CA, November 5-7, 2012 High Field Solenoid Program...

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Near-zero modes in superconducting graphene  

E-Print Network (OSTI)

Vortices in the simplest superconducting state of graphene contain very-low-energy excitations whose existence is connected to an index theorem that applies strictly to an approximate form of the relevant Bogoliubov–de ...

Ghaemi, Pouyan

382

Superconductivity for electric power systems: Program overview  

SciTech Connect

Largely due to government and private industry partnerships, electric power applications based upon high-temperature superconductivity are now being designed and tested only seven years after the discovery of the high-temperature superconductors. These applications offer many benefits to the national electric system including: increased energy efficiency, reduced equipment size, reduced emissions, increased stability/reliability, deferred expansion, and flexible electricity dispatch/load management. All of these benefits have a common outcome: lower electricity costs and improved environmental quality. The U.S. Department of Energy (DOE) sponsors research and development through its Superconductivity Program for Electric Power Systems. This program will help develop the technology needed for U.S. industries to commercialize high-temperature superconductive electric power applications. DOE envisions that by 2010 the U.S. electric power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition.

Not Available

1995-02-01T23:59:59.000Z

383

Cooling arrangement for a superconducting coil  

DOE Patents (OSTI)

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.

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

1998-06-30T23:59:59.000Z

384

Electromagnetic Modelling of Superconducting Sensor Designs  

E-Print Network (OSTI)

DEPARTMENT OF MATERIALS SCIENCE AND METALLURGY Electromagnetic Modelling of Superconducting Sensor Designs Guido Gerra Clare Hall, University of Cambridge 1 Preface The present dissertation has been submitted... and for all the moments they have shared with me. 4 Abstract The problem of design optimisation of thin film direct current Superconducting QUantum Interference Device (SQUID) magnetometers made of YBCO (YBa2Cu3O7-x) was considered. The inductances...

Gerra, Guido

385

Passive energy dump for superconducting coil protection  

DOE Patents (OSTI)

The patent describes a passive resistance type energy dump for the protection of the coils of a superconducting magnet. Insertion heaters are immersed in a rigid container filled with a fusible alloy. The energy dump is connected across the coils of the superconducting magnet wherein individual heater elements are connected singly to the windings or otherwise according to the energy dumping requirements upon transition of the magnet to a normal state.

Luton, J.N. Jr.

1973-01-16T23:59:59.000Z

386

Architecture for high critical current superconducting tapes  

DOE Patents (OSTI)

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.

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

2002-01-01T23:59:59.000Z

387

Superconductive microstrip exhibiting negative differential resistivity  

DOE Patents (OSTI)

A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor- depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current- induced resistive state.

Huebener, R.P.; Gallus, D.E.

1975-10-28T23:59:59.000Z

388

Armored spring-core superconducting cable and method of construction  

DOE Patents (OSTI)

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).

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

2002-01-01T23:59:59.000Z

389

Solution of thin film magnetization problems in type-II superconductivity  

Science Conference Proceedings (OSTI)

Keywords: critical current, numerical solution, superconductivity, thin film, variational inequality

Leonid Prigozhin

1998-07-01T23:59:59.000Z

390

Dynamics of Longitudinal Phase-Space Modulations in an rf Compressor for Electron Beams  

E-Print Network (OSTI)

gain along the rf compressor for perturbation wavelengths (drift followed by a 3 m rf compressor. The beam injected atat the exit of the compressor over a range of perturbation

Venturini, M.

2010-01-01T23:59:59.000Z

391

Dynamics of an electron in an rf gap  

Science Conference Proceedings (OSTI)

The purpose of this calculation is to understand the limitation on the energy transfer efficiency of an electron beam to the rf output cavity of a klystron or a lasertron. An output cavity with drift tubes is modeled in this calculation by a region of constant amplitude rf field with exponentially decreasing entrance and exit fringing fields. The exit velocity of an electron traversing such a gap is examined as a function of entrance phase for various values of the ratio of the peak rf cavity voltage to electron entrance voltage. Depending on this ratio, the dynamics of the electron motion can become quite complex. For a gap with fringe fields it is found that, even if the gap voltage and phase are optimized, the maximum energy that can be extracted from a short bunch is always significantly less than 100%. The case in which the electron is created with zero velocity in the gap, and subsequently leaves the gap having extracted energy from the rf field, is also treated. 4 refs., 10 figs.

Farkas, Z.D.; Wilson, P.B.

1989-03-01T23:59:59.000Z

392

RF Cherenkov picosecond timing technique for high energy physics applications  

Science Conference Proceedings (OSTI)

The Cherenkov time-of-propagation (TOP) detector and Cherenkov time-of-flight (TOF) detector in a ?head-on? geometry based on the recently proposed time measuring technique with radio frequency (RF) phototube are considered. Results of the Monte Carlo simulations are presented.

Margaryan, Amur; Hashimoto, Osamu; Majewski, Stanislaw; Tang, Liguang

2008-09-01T23:59:59.000Z

393

The RF, Communications and Intelligent Systems (RFCIS) Group  

E-Print Network (OSTI)

Federal Laboratory Consortium for Technology Transfer. Tagging, Tracking, and Locating Systems TTL and development (R&D) geared toward supplying robust communications for extreme environments; global tagging, tracking, and locating (TTL) systems; and RF- and microwave-based measurement and processing systems

394

RF coupler for high-power CW FEL photoinjector  

SciTech Connect

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. The design presently under way is a 100-mA 2.5-cell {pi}-mode, 700-MHz, normal conducting demonstration CW RF photoinjector. This photoinjector will be capable of accelerating 3 nC per bunch with an emittance at the wiggler less than 10 mm-mrad. The paper presents results for the RF coupling from ridged wave guides to hte photoinjector RF cavity. The LEDA and SNS couplers inspired this 'dog-bone' design. Electromagnetic modeling of the coupler-cavity system has been performed using both 2-D and 3-D frequency-domain calculations, and a novel time-domain approach with MicroWave Studio. These simulations were used to adjust the coupling coefficient and calculate the power-loss distribution on the coupling slot. The cooling of this slot is a rather challenging thermal management project.

Kurennoy, S. (Sergey); Young, L. M. (Lloyd M.)

2003-01-01T23:59:59.000Z

395

Stochastic fluctuations of dust particle charge in RF discharges  

Science Conference Proceedings (OSTI)

In addition to RF oscillations, intrinsic stochastic fluctuations due to the discreteness of electrons and ions could be important to the charging of a dust particle in RF discharges. These fluctuations are studied in the present work for three cases [M. Bacharis et al., Plasma Sources Sci. Technol. 19, 025002 (2010)] relevant to RF discharges employing a recently proposed model [B. Shotorban, Phys. Rev. E 83, 066403 (2011)] valid for stochastic charging at nonstationary states. The cases are concerned with a time varying electron number density relevant to sheaths, a time varying electric field relevant to the bulk plasma, and a time-dependent bi-Maxwellian distribution of electrons in a low pressure discharge. Two dust particles with different sizes are individually studied in each case. The radius of one is ten times larger than the radius of the other. In all of the cases, for the larger dust particle, the root-mean-squre of charge stochastic fluctuations is about an order of magnitude smaller than the amplitude of RF charge oscillations, while for the smaller dust particle, they are comparable in magnitude.

Shotorban, B. [Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)

2012-05-15T23:59:59.000Z

396

Tubular Radio Frequency (RF) Cage Field Confinement Cavity (IN-05-107)  

Scientists at Argonne National Laboratory have created innovations in the design and fabrication of radio frequency (RF) cavities that improve ...

397

Design of RF Feed System for Standing-Wave Accelerator Structures  

Science Conference Proceedings (OSTI)

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.

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

2012-05-25T23:59:59.000Z

398

Photon emission near superconducting bodies  

Science Conference Proceedings (OSTI)

We study the photon emission due to a magnetic spin-flip transition of a two-level atom in the vicinity of a dielectric body such as a normal conducting metal or a superconductor. For temperatures below the transition temperature T{sub c} of a superconductor, the corresponding spin-flip lifetime is boosted by several orders of magnitude as compared to the case of a normal conducting body. Numerical results of an exact formulation are also compared to a previously derived approximative analytical expression for the spin-flip lifetime, and we find excellent agreement. We present results on how the spin-flip lifetime depends on the temperature T of a superconducting body as well as its thickness H. Finally, we study how nonmagnetic impurities as well as possible Eliashberg strong-coupling effects influence the spin-flip rate. It is found that nonmagnetic impurities as well as strong-coupling effects have no dramatic impact on the spin-flip lifetime.

Skagerstam, Bo-Sture K.; Rekdal, Per Kristian [Department of Physics, The Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

2007-11-15T23:59:59.000Z

399

Some elementary theoretical considerations concerning superconductivity of superimposed metallic films  

Science Conference Proceedings (OSTI)

A microscopic theory of superconductivity of superimposed metallic films is proposed, based on the fact that thee lectron pair correlation function penetrates into a normal metal where the electron-electron interaction would not by itself produce a superconducting ...

L. N. Cooper

1962-01-01T23:59:59.000Z

400

High Temperature Superconductivity in Cuprates: a model  

E-Print Network (OSTI)

A model is proposed such that quasi-particles (electrons or holes) residing in the CuO2 planes of cuprates may interact leading to metallic or superconducting behaviors. The metallic phase is obtained when the quasi-particles are treated as having classical kinetic energies and the superconducting phase occurs when the quasi-particles are taken as extremely relativistic objects. The interaction between both kinds of particles is provided by a force dependent-on-velocity. In the case of the superconducting behavior, the motion of apical oxygen ions provides the glue to establish the Cooper pair. The model furnishes explicit relations for the Fermi velocity, the perpendicular and the in-plane coherence lengths, the zero-temperature energy gap, the critical current density, the critical parallel and perpendicular magnetic fields. All these mentioned quantities are expressed in terms of fundamental physical constants as: charge and mass of the electron, light velocity in vacuum, Planck constant, electric permittivity of the vacuum. Numerical evaluation of these quantities show that their values are close those found for the superconducting YBaCuO, leading to think the model as being a possible scenario to explain superconductivity in cuprates.

P. R. Silva

2010-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Superconductivity in bulk ultrafine-grained metals prepared by high ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Ultrafine Grained Materials VIII. Presentation Title, Superconductivity in bulk ...

402

RECENT ADVANCES IN THE TECHNOLOGY OF SUPERCONDUCTING ACCELERATOR MAGNETS  

E-Print Network (OSTI)

Accelerator Magnets,· Brookhaven National Laboratory,in Superconducting Magnets,- Brookhaven National Laboratory,Accelerator Magnet Wire," Brookhaven National Laboratory,

Taylor, C.E.

2010-01-01T23:59:59.000Z

403

Iron-based Materials May Unlock Superconductivity's Secrets  

Science Conference Proceedings (OSTI)

... wide use in next-generation systems for storing, distributing and using electricity. ... whose appearance shatters the fragile superconductive state. ...

2011-04-26T23:59:59.000Z

404

Proceedings of 2009 KEPRI-EPRI Joint Superconductivity Conference  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute (EPRI) and Korea Electric Power Research Institute (KEPRI) held the 2009 KEPRI-EPRI Joint Superconductivity Conference on November 1618, 2009 in Daejeon, Korea at KEPRIs facilities. The conference was the ninth in EPRIs series of annual superconductivity conferences. KEPRI, which is the research center of Korea Electric Power Corporation, cosponsored the event with EPRIs Superconductivity Program. The Korea Institute of Applied Superconductivity and Cryogenics was th...

2010-02-25T23:59:59.000Z

405

Study on the energy criterion of cuprate superconductivity  

E-Print Network (OSTI)

In this paper, we use the variation of spontaneous magnetization to describe the influence of electron holes in cuprate superconductors, and use competitive energy relations to explore the superconductivity rule and energy criterion, on this basis, we can deduce a clear physical image of superconducting phase diagram and superconducting mechanism.

Gu Jiapu

2007-07-07T23:59:59.000Z

406

rf power system for thrust measurements of a helicon plasma source  

SciTech Connect

A rf power system has been developed, which allows the use of rf plasma devices in an electric propulsion test facility without excessive noise pollution in thruster diagnostics. Of particular importance are thrust stand measurements, which were previously impossible due to noise. Three major changes were made to the rf power system: first, the cable connection was changed from a balanced transmission line to an unbalanced coaxial line. Second, the rf power cabinet was placed remotely in order to reduce vibration-induced noise in the thrust stand. Finally, a relationship between transmission line length and rf was developed, which allows good transmission of rf power from the matching network to the helicon antenna. The modified system was tested on a thrust measurement stand and showed that rf power has no statistically significant contribution to the thrust stand measurement.

Kieckhafer, Alexander W.; Walker, Mitchell L. R. [Department of Aerospace Engineering, High-Power Electric Propulsion Laboratory, College of Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2010-07-15T23:59:59.000Z

407

J-PARC Correctors | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnet Construction Magnet Construction The final turn of the J-PARC extracted proton beam is a superconducting combined function magnet line. The combined function magnets are dipole cable magnets, typical of cold mass collared magnets, but have been designed to include a large component of quadrupole field. This provides both bending and focussing of the proton beam prior to target impact, where neutrinos will be produced. The BNL Superconducting Magnet Division is using its direct wind facility to produce superconducting corrector magnets to be used in conjunction with the combined function magnets. combined function magnet The first direct wind magnet set designed and fabricated is a combined function magnet with an additional skew dipole. This magnet is intended to be used within the cable collared combined function dipole used for the

408

Superconducting magnetic shielding apparatus and method  

DOE Patents (OSTI)

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.

Clem, J.R.

1982-07-09T23:59:59.000Z

409

Superconducting magnetic shielding apparatus and method  

DOE Patents (OSTI)

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.

Clem, J.R.; Clem, J.R.

1983-10-11T23:59:59.000Z

410

Superconducting magnetic shielding apparatus and method  

DOE Patents (OSTI)

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.

Clem, John R. (Ames, IA); Clem, John R. (Ames, IA)

1983-01-01T23:59:59.000Z

411

Improved Superconducting Wire for Wind Generators: Superconducting Wires for Direct-Drive Wind Generators  

SciTech Connect

REACT Project: Brookhaven National Laboratory will develop a low-cost superconducting wire that could be used in high-power wind generators. Superconducting wire currently transports 600 times more electric current than a similarly sized copper wire, but is significantly more expensive. Brookhaven National Laboratory will develop a high-performance superconducting wire that can handle significantly more electrical current, and will demonstrate an advanced manufacturing process that has the potential to yield a several-fold reduction in wire costs while using a using negligible amount of rare earth material. This design has the potential to make a wind turbine generator lighter, more powerful, and more efficient, particularly for offshore applications.

2012-01-01T23:59:59.000Z

412

Free electron laser using Rf coupled accelerating and decelerating structures  

DOE Patents (OSTI)

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.

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

1984-01-01T23:59:59.000Z

413

National rf technology research and development program plan  

Science Conference Proceedings (OSTI)

This plan was prepared by the Oak Ridge National Laboratory at the request of the Office of Fusion Energy, Division of Development and Technology, to define the technology development needs and priorities. The US rf research and development community, with a wide representation from universities, laboratories and industries, participated in many discussions, meetings and in a three-day workshop in developing the needs and priorities definition. This very active and effective involvement of the rf leaders from all of these groups was an essential feature of the activity and results in the plan representing a broad consensus from the magnetic fusion energy development community. In addition, a number of scientists from Japan and Europe participated by providing data.

Not Available

1983-05-01T23:59:59.000Z

414

Design of RF systems for the RTD mission VASIMR  

SciTech Connect

The first flight test of the variable specific impulse magnetoplasma rocket (VASIMR) is tentatively scheduled for the Radiation and Technology Demonstration (RTD) in 2003. This mission to map the radiation environment out to several earth radii will employ both a Hall thruster and a VASIMR during its six months duration, beginning from low earth orbit. The mission will be powered by a solar array providing 12 kW of direct current electricity at 50 V. The VASIMR utilizes radiofrequency (RF) power both to generate a high-density plasma in a helicon source and to accelerate the plasma ions to high velocity by ion cyclotron resonance heating (ICRH). The VASIMR concept is being developed by the National Aeronautics and Space Administration (NASA) in collaboration with national laboratories and universities. Prototype plasma sources, RF amplifiers, and antennas are being developed in the experimental facilities of the Advanced Space Propulsion Laboratory (ASPL). (c) 1999 American Institute of Physics.

Baity, F. W. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Barber, G. C. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Carter, M. D. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Goulding, R. H. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Sparks, D. O. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Chang-Diaz, F. R. [Advanced Space Propulsion Laboratory, NASA, Johnson Space Center, Houston, Texas 77059 (United States); McCaskill, G. E. [Advanced Space Propulsion Laboratory, NASA, Johnson Space Center, Houston, Texas 77059 (United States); Squire, J. P. [Advanced Space Propulsion Laboratory, NASA, Johnson Space Center, Houston, Texas 77059 (United States)

1999-09-20T23:59:59.000Z

415

Design of RF Systems for the RTD Mission VASIMR  

SciTech Connect

The first flight test of the variable specific impulse magnetoplasma rocket (VASIMR) is tentatively scheduled for the Radiation and Technology Demonstration (RTD) in 2003. This mission to map the radiation environment out to several earth radii will employ both a Hall thruster and a VASIMR during its six months duration, beginning from low earth orbit. The mission will be powered by a solar array providing 12 kW of direct current electricity at 50 V. The VASIMR utilizes radiofrequency (RF) power both to generate a high-density plasma in a helicon source and to accelerate the plasma ions to high velocity by ion cyclotron resonance heating (ICRH). The VASIMR concept is being developed by the National Aeronautics and Space Administration (NASA) in collaboration with national laboratories and universities. Prototype plasma sources, RF amplifiers, and antennas are being developed in the experimental facilities of the Advanced Space Propulsion Laboratory (ASPL).

Baity, F.W.; Barber, G.C.; Carter, M.D.; Chang-Diaz, F.R.; Goulding, R.H.; McCaskill, G.E.; Sparks, D.O.; Squire, J.P.

1999-04-12T23:59:59.000Z

416

Resonant ring for testing of accelerator RF windows  

SciTech Connect

A klystron-driven resonant ring has been designed and assembled at the Los Alamos National Laboratory for use in the Accelerator Production of Tritium Project (APT). The ring was built to test rf windows for the 700 MHz section of the APT accelerator. The ring has been designed to apply an effective power of approximately 1 MW on test windows. Details of ring design, operation and performance will be presented.

Gerken, E.; Rees, D.; Roybal, W.; Cummings, K. [Los Alamos National Lab., NM (United States); Gahl, J.M. [Univ. of New Mexico, Albuquerque, NM (United States)

1997-09-01T23:59:59.000Z

417

Criterion of stability of the superconducting state  

E-Print Network (OSTI)

In this paper, we propose to draw attention to the stability criterion of the superconductor current state. We use for this purpose the rough systems mathematical apparatus allowing us to relate the desired criterion with the dielectric permittivity of the matter and to identify the type of all possible phonons trajectories in its superconducting state. The state of superconductivity in the matter can be explained only by the phonons behavior peculiarity. And on the basis of the above-mentioned assumption, the corresponding mathematical model is constructed.

Iogann Tolbatov

2009-10-23T23:59:59.000Z

418

Safety and reliability in superconducting MHD magnets  

DOE Green Energy (OSTI)

This compilation adapts studies on safety and reliability in fusion magnets to similar problems in superconducting MHD magnets. MHD base load magnet requirements have been identified from recent Francis Bitter National Laboratory reports and that of other contracts. Information relevant to this subject in recent base load magnet design reports for AVCO - Everett Research Laboratories and Magnetic Corporation of America is included together with some viewpoints from a BNL workshop on structural analysis needed for superconducting coils in magnetic fusion energy. A summary of design codes used in large bubble chamber magnet design is also included.

Laverick, C.; Powell, J.; Hsieh, S.; Reich, M.; Botts, T.; Prodell, A.

1979-07-01T23:59:59.000Z

419

On Color Superconductivity in External Magnetic Field  

E-Print Network (OSTI)

We study color superconductivity in external magnetic field. We discuss the reason why the mixing angles in color-flavor locked (CFL) and two-flavor superconductivity (2SC) phases are different despite the fact that the CFL gap goes to the 2SC gap for $m_s \\to \\infty$. Although flavor symmetry is explicitly broken in external magnetic field, we show that all values of gaps in their coset spaces of possible solutions in the CFL phase are equivalent in external magnetic field.

E. V. Gorbar

2000-01-20T23:59:59.000Z

420

Superconducting phases of f-electron compounds  

E-Print Network (OSTI)

Superconductivity was discovered almost a century ago. Yet, unexpected and fascinating new variants of this same old theme are being found at an increasing pace. This is due to great technical advances in materials preparation and an increasingly more systematic screening of new compounds. Prior to the late 1970s all known superconductors could be accounted for in terms of a condensate of Cooper pairs, where the Cooper pairs form due to electron-phonon interactions. With the discovery of the superfluid phases of 3He this understanding began to change in two ways (Osheroff et al., 1972; Vollhardt and Wölfle, 1990). First, 3He provided an example of non-electron-phonon mediated pairing. Second, it provided an example of a superfluid condensate that breaks additional symmetries. The discovery of heavy-fermion superconductivity as a prime candidate for complex order parameter symmetries and non-electron-phonon mediated pairing in f-electron compounds nearly three decades ago was long recognized as an important turning point in the history of superconductivity. However, progress in heavy fermion superconductivity until not long ago seemed to have been slow. In recent years especially the superconductivity in the cuprates, ruthenates, cobaltates, pyrochlores and ironpnictides received great attention. However, a spectacular series of discoveries and developments in f-electron superconductors took place at the same time. While in the first twelve years following the discovery of heavyfermion superconductivity in CeCu2Si2 only five more heavy fermion superconductors could be identified, over twenty five additional systems have been found in the past fifteen years (see Fig. 1). By now over thirty systems are known, about half of which were discovered in the past five years alone. This illustrates the speed of development the field of f-electron superconductivity has picked up despite its long tradition. As a result there is growing appreciation that superconducting phases of f-electron compounds frequently exist at the border of competing and coexisting forms of electronic order. For the majority of systems, including the original heavy-fermion superconductors, an inarXiv:0905.2625v1

Christian Pfleiderer

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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421

Apparatus for characterizing conductivity of superconducting materials  

DOE Patents (OSTI)

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.

Doss, J.D.

1993-12-07T23:59:59.000Z

422

RF Choke for Standing Wave Structures and Flanges  

DOE Green Energy (OSTI)

SLAC participates in the U.S. High Gradient collaboration whose charter includes basic studies of rf breakdown properties in accelerating structures. These studies include experiments with different materials and construction methods for single cell standing wave accelerating structures. The most commonly used method of joining cells of such structures is the high temperature bonding and/or brazing in hydrogen and/or vacuum. These high temperature processes may not be suitable for some of the new materials that are under consideration. We propose to build structures from cells with an rf choke, taking the cell-to-cell junction out of the electromagnetic field region. These cells may be clamped together in a vacuum enclosure, the choke joint ensuring continuity of rf currents. Next, we propose a structure with a choke joint in a high gradient cell and a view port which may allow us microscopic, in-situ observation of the metal surface during high power tests. And third, we describe the design of a TM01 choke flange for these structures.

Yeremian, Anahid; /SLAC; Dolgashev, Valery; /SLAC; Tantawi, Sami; /SLAC

2012-07-03T23:59:59.000Z

423

Color symmetric superconductivity in a phenomenological QCD model  

E-Print Network (OSTI)

In this paper, we construct a theory of the NJL-type where superconductivity is present, and yet the super-conducting state remains, in the average, color symmetric. This shows that the present approach to color superconductivity is consistent with color singlet-ness. Indeed, quarks are free in the deconfined phase, but the deconfined phase itself is believed to be a color singlet. The usual description of the color superconducting state violates color singlet-ness. On the other hand, the color superconducting state here proposed, is color symmetric in the sense that an arbitrary color rotation leads to an equivalent state, with precisely the same physical properties.

Henrik Bohr; Constança Providência; João da Providência

2009-09-19T23:59:59.000Z

424

Pseudogap and Superconducting Gap in High-Temperature Superconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogap and Superconducting Gap in Pseudogap and Superconducting Gap in High-Temperature Superconductors Two decades after the discovery of first high temperature superconductors, the microscopic mechanism of high-Tc superconductivity remains elusive. In conventional superconductors, it has been well established that electrons form so-called "Cooper pairs" to give rise to superconductivity. The pair binding manifests itself as an energy gap in many spectroscopic measurements. This energy gap, known as superconducting gap, appears at the superconducting transition temperature Tc where the resistance also vanishes. For high temperature superconductors, the story is more complicated. Over a wide region of compositions and temperatures, there exists an energy gap well above Tc. This energy gap is called pseudogap [1], because there is no direct correlation to the superconducting transition. The origin of this pseudogap and its relation to the superconducting gap are believed to hold the key for understanding the mechanism of high-Tc superconductivity - one of the outstanding problems in condensed matter physics. In this regard, researchers Kiyohisa Tanaka and Wei-Sheng Lee, along with their co-workers in Prof. Zhi-Xun Shen's group at Stanford University, have recently made an important discovery about the coexistence of two distinct energy gaps that have opposite doping dependence. Their observation not only provides a natural explanation for the contradictory results about the superconducting gap deduced from different experimental techniques, but also has profound implications on the mechanism of high-Tc superconductivity.

425

A Cryogenic RF Material Testing Facility at SLAC  

SciTech Connect

The authors have developed an X-band SRF testing system using a high-Q copper cavity with an interchangeable flat bottom for the testing of different materials. By measuring the Q of the cavity, the system is capable to characterize the quenching magnetic field of the superconducting samples at different power level and temperature, as well as the surface resistivity. This paper presents the most recent development of the system and testing results.

Guo, Jiquan; Martin, David; Tantawi, Sami; Yoneda, Charles; /SLAC

2012-06-22T23:59:59.000Z

426

Termination for superconducting power transmission systems  

DOE Patents (OSTI)

This patent relates to a cold, electrical gradient, terminal section for a superconducting cable for alternating current power transmission. A cold electrical gradient section filled with a gaseous coolant acting as an insulator is provided in series with a separate thermal gradient section. (auth)

Forsyth, E.B.; Jensen, J.E.

1975-08-26T23:59:59.000Z

427

High temperature superconducting fault current limiter  

DOE Patents (OSTI)

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.

Hull, J.R.

1997-02-04T23:59:59.000Z

428

Positive and inverse isotope effect on superconductivity  

E-Print Network (OSTI)

This article improves the BCS theory to include the inverse isotope effect on superconductivity. An affective model can be deduced from the model including electron-phonon interactions, and the phonon-induced attraction is simply and clearly explained on the electron Green function. The focus of this work is on how the positive or inverse isotope effect occurs in superconductors.

Tian De Cao

2009-09-04T23:59:59.000Z

429

Color superconductivity and the strange quark  

E-Print Network (OSTI)

At ultra-high density, matter is expected to form a degenerate Fermi gas of quarks in which there is a condensate of Cooper pairs of quarks near the Fermi surface: color superconductivity. In these proceedings I review some of the underlying physics, and discuss outstanding questions about the phase structure of ultra-dense quark matter.

Mark G Alford

2005-12-01T23:59:59.000Z

430

Active superconducting devices formed of thin films  

DOE Patents (OSTI)

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.

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

1991-05-28T23:59:59.000Z

431

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

Science Conference Proceedings (OSTI)

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.

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

2011-03-03T23:59:59.000Z

432

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

DOE Patents (OSTI)

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.

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

2013-01-15T23:59:59.000Z

433

Production and decay properties of the 1.9-s isomeric state in {sup 261}Rf  

SciTech Connect

The 1.9-s isomeric state ({sup 261}Rf{sup b}) in {sup 261}Rf was directly populated in the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction. Alpha and spontaneous fission (SF) decays of {sup 261}Rf{sup b}, as well as the 68-s state {sup 261}Rf{sup a}, was investigated with a rotating wheel apparatus under low background conditions attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. An identification of {sup 261}Rf{sup b} was based on {alpha}-{alpha} correlations linking {alpha} decays of {sup 261}Rf{sup b} and its daughter {sup 257}No. The {alpha}-particle energy of {sup 261}Rf{sup b} was measured to be 8.52 {+-} 0.05 MeV. The half-life was determined to be 1.9 {+-} 0.4 s based on both 8.52-MeV {alpha} and SF decays. The {alpha} and SF branches are 0.27 {+-} 0.06 and 0.73 {+-} 0.06, respectively. The cross section for the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction is {sigma}({sup 261}Rf{sup b}) = 11 {+-} 2 nb at 95.1 MeV, which gives a cross-section ratio of {sigma}({sup 261}Rf{sup a})/{sigma}({sup 261}Rf{sup b}) = 1.1 {+-} 0.2.

Haba, H.; Kaji, D.; Kikunaga, H.; Kudou, Y.; Morimoto, K.; Morita, K.; Ozeki, K.; Sumita, T.; Yoneda, A.; Kasamatsu, Y.; Komori, Y.; Ooe, K.; Shinohara, A. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2011-03-15T23:59:59.000Z

434

Surface Characterization of the LCLS RF Gun Cathode  

Science Conference Proceedings (OSTI)

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.

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

2012-06-25T23:59:59.000Z

435

Optical Emission of Dusty RF Discharges: Experiment and Simulation  

Science Conference Proceedings (OSTI)

The spectral emission of argon atoms in a dusty radio frequence (RF) discharge has been investigated experimentally and in simulations. It was observed that the spatially and temporally resolved emission of the argon atoms in the dusty discharge was increased compared to the dust-free case during sheath expansion. The corresponding simulations have revealed that the dust trapped in the sheath of the discharge leads to a small, but important, increase of the amount of high-energy electrons that in turn leads to an increased argon emission.

Melzer, A.; Lewerentz, L.; Schneider, R. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Huebner, S. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Department of Applied Physics, Technical University Eindhoven, NL-5600 MB Eindhoven (Netherlands); Matyash, K. [Max-Planck-Institute for Plasma Physics, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, V. R. [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

2011-11-29T23:59:59.000Z

436

Doped H(2)-Filled RF Cavities for Muon Beam Cooling  

DOE Green Energy (OSTI)

RF cavities pressurized with hydrogen gas may provide effective muon beam ionization cooling needed for muon colliders. Recent 805 MHz test cell studies reported below include the first use of SF{sub 6} dopant to reduce the effects of the electrons that will be produced by the ionization cooling process in hydrogen or helium. Measurements of maximum gradient in the Paschen region are compared to a simulation model for a 0.01% SF{sub 6} doping of hydrogen. The observed good agreement of the model with the measurements is a prerequisite to the investigation of other dopants.

Yonehara, K.; Chung, M.; Jansson, A.; Hu, M.; Moretti, A.; Popovic, M.; /Fermilab; Alsharo'a, M.; Johnson, R.P.; Neubauer, M.; Sah, R.; /Muons Inc., Batavia; Rose, D.V.; /Voss Sci., Albuquerque

2009-05-01T23:59:59.000Z

437

Capacitively coupled RF voltage probe having optimized flux linkage  

DOE Patents (OSTI)

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.

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

1999-02-02T23:59:59.000Z

438

Field Emission Cathode Gating for RF Electron Guns (IN-04-039)  

Scientists at Argonne National Laboratory have created an innovative way to enhance the performance of radio frequency (RF) electron guns: a method of ...

439

Torsional texturing of superconducting oxide composite articles  

DOE Patents (OSTI)

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.

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

2002-01-01T23:59:59.000Z

440

Intrinsic fluctuation effects and certain other aspects of superconducting weak links  

SciTech Connect

Thesis. Recent theoretical developments have led to evermore refined theories for the Josephson effects in a variety of superconducting weak link'' structures. One of the major refinements has been the inclusion of the effects of intrinsic thermal fluctuations upon Josephson-like behavior. Some other developments include the investigation of mechanisms for the origin of the Josephson effects in non-tunneling structures, and equivalent circuit representations. Experimental investigations were made which encompass both of these areas; with special emphaais placed upon fluctuation effects; in pariicular, the effect of fluctuations upon the driven dc Josephson effect has been studied in considerable detail. The weak links studied included niobium point contacts, tin whisker'' crystals, and tin thin film bridges, the latter fabricated via an optical photoresist technique. The experiments were conducted in a temperature regime which extended to within a few mK of T/sub c/, the regime in which fluctuation effects are enhanced (and thus tnore experimentally accessible). The data consisted of relatively high resolution (ln V) low noise 1- -V characteristics obtained with an apparatus which incorporated ( plus or minus 10 mu K) temperature control with wide-band rf transmission, in a highly shielded environment. Experiniental rf-induced step pi-ofiles (the driven ac Josephsorin effect) and zero voltage step profiles (the dc Josephson effect) were compared in detail with the relevant intrinsic fluctuation theories (due to Ambegaokar, Halperin, and Stephen) via a one parameter fit, using the respective no-fluctuation step amplitude as she (natural) fitting parameter. We were able to distinguish between external noise effects and intrinsic effects and effectively excluded external noise; thus we maintain a high degree of confidence that the effects reported are indeed intrinsic to the weak links themselves. The agreement between thcory arind experinient was found to be very good in both the driven and the dc effects over a wide range of experimertal parameters and the single-parameter fits yielded step heights which corresponded reasonably well to the dc critical currents. These results indicate that the conceptually simple theory in which thermal fluctuations are introduced as a rapidly fluctuating (Langevin) force and a tilted periodic potential is introduced by the coupling energy (dc effect) or by phase locking to incident radiation (driven ac effect) provides a rather good description of the intrinsic fluctuation phenomena in superconducting weak links of negligible capacitance. The broad applicability of the theoretical concepts is indicated by the consisterincy between the dc and driven effect results, and by-the wide range of parameters over which convincing agreement between theory and experiment was obtained. By making some observations in regimes where fluctuation effects were diminished. evidence was found that slight deviations that were observed in the fluctuation experments could be attributed to deviations from the no-fluctuation model used as the starting point in the fluctuation theories. Supplemental considerations related to junction modeling were also pursued to a certain degree and irin some cases, led to new results or confirmations of recently discovered results of other researchers. These observations included 1--V comparisons, rf step amplitude vs voltage dependences, rf step threshold frequencies, and the Dayem --Wyatt effect. (122 references, 84 figures) (auth)

Henkels, W.H.

1974-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

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

Science Conference Proceedings (OSTI)

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.

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

2011-07-25T23:59:59.000Z

442

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

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print 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 oxide materials (cuprates). This discovery casts new doubts on any direct link between the pseudogap phase and high-temperature superconductivity and adds fire to the debate over one of the great scientific mysteries of our time: What causes high-temperature superconductivity?

443

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

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print 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 oxide materials (cuprates). This discovery casts new doubts on any direct link between the pseudogap phase and high-temperature superconductivity and adds fire to the debate over one of the great scientific mysteries of our time: What causes high-temperature superconductivity?

444

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

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogaps, Polarons, and the 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 these manganites is remarkably similar to that found in high-temperature superconducting copper oxide materials (cuprates). This discovery casts new doubts on any direct link between the pseudogap phase and high-temperature superconductivity and adds fire to the debate over one of the great scientific mysteries of our time: What causes high-temperature superconductivity?

445

ORNL Publishes Study on Superconducting Wire Performance | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ORNL Publishes Study on Superconducting Wire Performance 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 findings are published in Nature Publishing Group's Scientific Reports. The full press release and link to the new report are available on ORNL's website. Dr. Goyal, a high temperature superconductivity (HTS) research at ORNL, won the Department's 2011 E.O. Lawrence Award in the inaugural category of

446

Color superconductivity with determinant interaction in strange quark matter  

E-Print Network (OSTI)

We investigate the effect of six fermion determinant interaction on color superconductivity as well as on chiral symmetry breaking. Coupled mass gap equations and the superconducting gap equation are derived through the minimisation of the thermodynamic potential. The effect of nonzero quark -- antiquark condensates on the superconducting gap is derived. This becomes particularly relevant for the case of 2-flavor superconducting matter with unpaired strange quarks in the diquark channel. While the effect of six fermion interaction leads to an enhancement of u-d superconductivity, due to nonvanishing strange quark--antiquark condensates, such an enhancement will be absent at higher densities for u-s or d-s superconductivity due to early (almost) vanishing of light quark-- antiquark condensates.

Amruta Mishra; Hiranmaya Mishra

2006-05-21T23:59:59.000Z

447

Plasma properties of RF magnetron sputtering system using Zn target  

Science Conference Proceedings (OSTI)

In the present work, we investigate the fundamental properties of magnetron sputtering plasma using Zn target and its deposited Zn thin film. The magnetron sputtering plasma was produced using radio frequency (RF) power supply and Argon (Ar) as ambient gas. A Langmuir probe was used to collect the current from the plasma and from the current intensity, we calculate the electron density and electron temperature. The properties of Zn sputtering plasma at various discharge conditions were studied. At the RF power ranging from 20 to 100 W and gas pressure 5 mTorr, we found that the electron temperature was almost unchanged between 2-2.5 eV. On the other hand, the electron temperature increased drastically from 6 Multiplication-Sign 10{sup 9} to 1 Multiplication-Sign 10{sup 10}cm{sup -3} when the discharge gas pressure increased from 5 to 10 mTorr. The electron microscope images show that the grain size of Zn thin film increase when the discharge power is increased. This may be due to the enhancement of plasma density and sputtered Zn density.

Nafarizal, N.; Andreas Albert, A. R.; Sharifah Amirah, A. S.; Salwa, O.; Riyaz Ahmad, M. A. [Microelectronic and Nanotechnology - Shamsuddin Research Centre (MiNT-SRC), Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

2012-06-29T23:59:59.000Z

448

Index of /research/alcator/facility/Procedures/RF  

NLE Websites -- All DOE Office Websites (Extended Search)

RF RF [ICO] Name Last modified Size Description [DIR] Parent Directory - [ ] 0D8C3B68.pdf 08-May-2003 07:16 60K [ ] 0D8C3B68 Driver Kaptons.PDF 08-May-2003 07:16 69K [ ] 2002-10-28 - FMIT-3 Tuning to 78 MHZ.pdf 08-May-2003 07:16 425K [ ] FMIT 1 Crowb-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 1 Trans-cess.doc..pdf 08-May-2003 07:16 38K [ ] FMIT 1 Transformer Entry.pdf 08-May-2003 07:16 46K [ ] FMIT 2 Crowba-et access.pdf 08-May-2003 07:16 38K [ ] FMIT 2 Trans-cess.doc..pdf 08-May-2003 07:16 38K [ ] FMIT 2 Transformer Entry.pdf 08-May-2003 07:16 46K [ ] FMIT 3 Crowb-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 3 Trans-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 4 Crowb-et Access.pdf 08-May-2003 07:16 38K

449

Superconductivity with stripes | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Science Computing, Environment & Life Sciences Energy Engineering & Systems Analysis Photon Sciences Physical Sciences & Engineering Energy Frontier Research Centers Science Highlights Postdoctoral Researchers The brightness and energy of X-ray beams are critical properties for research. The APS Upgrade will make our X-ray beams brighter, meaning more X-rays can be focused onto a smaller, laser-like spot, allowing researchers to gather more data in greater detail in less time. Superconductivity with stripes November 12, 2013 Tweet EmailPrint The physics of low-temperature superconductivity is fairly well understood, but the ultimate goal of achieving the phenomenon at much higher temperatures remains tantalizingly elusive. The most promising high-temperature superconductor candidates are generally considered to be

450

Energy Programs | Center for Emergent Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Center for Emergent Superconductivity (CES) Center for Emergent Superconductivity (CES) The mission of the CES is to advance the frontier of understanding and control of the materials, mechanisms, and critical currents of superconductors, including existing and new materials, and to communicate Center and other research results throughout national and international communities. More... Principal Investigators CES News Publications Recent CES Presentations EFRC Acknowledgements Reference Document (pdf) Guide to EFRC Science Review Documents (pdf) CES-EFRC Materials Catalog (restricted) CES-EFRC April 2009 Kickoff Meeting (restricted) CES-EFRC 2010 Winter Workshop (restricted) CES Fall Workshop: 2013 | 2012 | 2011 | 2010 April 2, 2012 Review (restricted) Story Archives Recent News atomic-scale microscopy Opposing Phenomena Possible Key to High-Efficiency Electricity Delivery

451

Energy Extraction for the LHC Superconducting Circuits  

E-Print Network (OSTI)

The superconducting magnets of the LHC will be powered in about 1700 electrical circuits. The energy stored in circuits, up to 1.3 GJ, can potentially cause severe damage of magnets, bus bars and current leads. In order to protect the superconducting elements after a resistive transition, the energy is dissipated into a dump resistor installed in series with the magnet chain that is switched into the circuit by opening current breakers. Experiments and simulation studies have been performed to identify the LHC circuits that need energy extraction. The required values of the extraction resistors have been computed. The outcome of the experimental results and the simulation studies are presented and the design of the different energy extraction systems that operate at 600 A and at 13 kA is described.

Dahlerup-Petersen, K; Schmidt, R; Sonnemann, F

2001-01-01T23:59:59.000Z

452

Superconductivity and the BCS-Bogoliubov Theory  

E-Print Network (OSTI)

First, we reformulate the BCS-Bogoliubov theory of superconductivity from the viewpoint of linear algebra. We define the BCS Hamiltonian on $\\mathbb{C}^{2^{2M}}$, where $M$ is a positive integer. We discuss selfadjointness and symmetry of the BCS Hamiltonian as well as spontaneous symmetry breaking. Beginning with the gap equation, we give the well-known expression for the BCS state and find the existence of an energy gap. We also show that the BCS state has a lower energy than the normal state. Second, we introduce a new superconducting state explicitly and show from the viewpoint of linear algebra that this new state has a lower energy than the BCS state. Third, beginning with our new gap equation, we show from the viewpoint of linear algebra that we arrive at the results similar to those in the BCS-Bogoliubov theory.

Shuji Watanabe

2010-06-07T23:59:59.000Z

453

Method of fabricating composite superconducting wire  

DOE Patents (OSTI)

An improvement in the method for preparing composite rods of superconducting alloy and normal metal from which multifilament composite superconducting wire is fabricated by bending longitudinally a strip of normal metal around a rod of superconductor alloy and welding the edges to form the composite rod. After the rods have preferably been provided with a hexagonal cross-sectional shape, a plurality of the rods are stacked into a normal metal extrusion can, sealed and worked to reduce the cross-sectional size and form multifilament wire. Diffusion barriers and high-electrical resistance barriers can easily be introduced into the wire by plating or otherwise coating the faces of the normal metal strip with appropriate materials.

Strauss, Bruce P. (Downers Grove, IL); Reardon, Paul J. (Princeton, NJ); Remsbottom, Robert H. (Middleton, WI)

1977-01-01T23:59:59.000Z

454

Overview of Superconductivity and Challenges in Applications  

E-Print Network (OSTI)

Considerable progress has been achieved during the last few decades in the various fields of applied superconductivity, while the related low temperature technology has reached a high level. Magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) are so far the most successful applications, with tens of thousands of units worldwide, but high potential can also be recognized in the energy sector, with high energy cables, transformers, motors, generators for wind turbines, fault current limiters and devices for magnetic energy storage. A large number of magnet and cable prototypes have been constructed, showing in all cases high reliability. Large projects involving the construction of magnets, solenoids as well as dipoles and quadrupoles are described in the present book. A very large project, the LHC, is currently in operation, demonstrating that superconductivity is a reliable technology, even in a device of unprecedented high complexity. A project of similar complexity is ITER, a fusion device...

Flükiger, Rene

2012-01-01T23:59:59.000Z

455

High-temperature superconducting current leads  

Science Conference Proceedings (OSTI)

Use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature can reduce refrigeration requirements to values significantly below those achievable with conventional leads. HTS leads are now near commercial realization. Argonne National Laboratory (ANL) has developed a sinter-forge process to fabricate current leads from bismuth-based superconductors. The current-carrying capacity of these leads is five times better than that of HTS leads made by a conventional fabrication process. ANL along with Superconductivity, Inc., has developed a 1500 ampere current lead for an existing superconducting magnetic energy storage (SMES) device. With Babcock & Wilcox Company, Argonne is creating 16-kiloampere leads for use in a 0.5 MWh SMES. In a third project Argonne performed characterization testing of a existing, proprietary conduction-cooled lead being developed by Zer Res Corp.

Niemann, R.C.

1995-03-01T23:59:59.000Z

456

High-Temperature Superconductivity Cable Demonstration Projects  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Temperature Temperature Superconductivity Cable Demonstration Projects Superconductivity Power Equipment 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 "A National Effort to Introduce New Technology into the Power Delivery Infrastructure" "In order to meet President Obama's ambitious energy goals, we must modernize the nation's electrical grid to improve the transmission, storage and reliability of clean energy across the country and help to move renewable energy from the places it can be produced to the places it can be used. The Department of Energy is working with industry partners to develop the

457

Use of superconductive technology for energy storage and power transmission for large power systems: power parks  

DOE Green Energy (OSTI)

A general review and technology assessment of superconducting magnets for energy storage and superconducting cables for power transmission are presented. It is concluded that the technology is now available for applying superconductivity in the power industry. (TFD)

Keller, W.E.

1977-01-01T23:59:59.000Z

458

Superconducting Power Equipment: Technology Watch 2012  

Science Conference Proceedings (OSTI)

The demand to transport large quantities of renewable energy from wind, solar, or hydro projects in remote locations to population load centers is increasing worldwide. Improved efficiency and greater power capacity that superconducting cables provide in this application continue to attract interest. In the United States, the Tres Amigas interconnect project, which reportedly will eventually use dc superconductors, is, in part, motivated by the need to transport wind power from west to east. ...

2012-12-20T23:59:59.000Z

459

Specifying and Testing Superconducting Power Equipment  

Science Conference Proceedings (OSTI)

EPRI held a workshop on September 21, 2007 in Hauppauge, New York to discuss what is needed to develop standards and specifications for testing superconducting power equipment. Stakeholders, including developers, equipment manufacturers, and electric utilities, participated in the discussions, which were arranged in a semi-formal setting to promote open dialogue. The U.S. Department of Energy provided assistance with meeting facilitation and recording.

2008-07-22T23:59:59.000Z

460

Holographic Superconductivity with Gauss-Bonnet gravity  

E-Print Network (OSTI)

I review recent work on holographic superconductivity with Einstein-Gauss-Bonnet gravity, and show how the critical temperature of the superconductor depends on both gravitational backreaction and the Gauss-Bonnet parameter, using both analytic and numerical arguments. I also review computations of the conductivity, finding the energy gap, and demonstrating that there is no universal gap ratio, $\\omega_g/T_c$, for these superconductors.

Ruth Gregory

2010-12-07T23:59:59.000Z

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461

Compact Superconducting Crabbing and Deflecting Cavities  

SciTech Connect

Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM{sub 110} cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

De Silva, Payagalage Subashini Uddika [JLAB, Old Dominion U.

2012-09-01T23:59:59.000Z

462

On a Model of Superconductivity and Biology  

E-Print Network (OSTI)

The paper deals with a semilinear integrodifferential equation that characterizes several dissipative models of Viscoelasticity, Biology and Superconductivity. The initial - boundary problem with Neumann conditions is analyzed. When the source term F is a linear function, then the explicit solution is obtained. When F is non linear, some results on existence, uniqueness and a priori estimates are deduced. As example of physical model the reaction - diffusion system of Fitzhugh Nagumo is considered.

Monica De Angelis

2012-03-02T23:59:59.000Z

463

High temperature superconductivity in metallic region near Mott transition  

E-Print Network (OSTI)

The spin-singlet superconductivity without phonons is examined in consideration of correlations on an extended Hubbard model. It is shown that the superconductivity requires not only the total correlation should be strong enough but also the density of state around Fermi energy should be large enough, which shows that the high temperature superconductivity could only be found in the metallic region near the Mott metal insulator transition (MIT). Other properties of superconductors are also discussed on these conclusions.

Tian De Cao

2009-06-11T23:59:59.000Z

464

Method for manufacturing a rotor having superconducting coils  

DOE Patents (OSTI)

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.

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

2001-01-01T23:59:59.000Z

465

Substrates suitable for deposition of superconducting thin films  

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

466

Strategic Intelligence Update: Superconductivity for Power Delivery Applications, April 2013  

Science Conference Proceedings (OSTI)

EPRI’s Strategic Intelligence Update: Superconductivity for Power Delivery Applications newsletter is part of its commitment to keep its members informed on the latest industry news and intelligence. Superconductivity is a rapidly evolving field, and this newsletter—along with EPRI’s annual Technology Watch reports—will closely follow developments in key technologies, R&D programs, demonstrations, deployments, and other superconductivity activities. The ...

2013-04-30T23:59:59.000Z

467

Superconductivity, superfluidity and zero-point oscillations  

E-Print Network (OSTI)

Currently it is thought that in order to explain the phenomenon of superconductivity is necessary to understand the mechanism of formation of electron pairs. However, the paired electrons cannot form a superconducting condensate. They perform disorderly zero-point oscillations and there are no attractive forces in their ensemble. To create a unified ensemble of particles, the pairs must order their zero-point fluctuations so that an attraction between the particles appears. For this reason, the ordering of zero-point oscillations in the electron gas is the cause of superconductivity and the parameters characterizing this order determine the properties of superconductors. The model of condensation of zero-point oscillations creates the possibility to obtain estimates for the critical parameters of elementary superconductors, which are also in the satisfactory agreement with measured data. On the another hand, the phenomenon of superfluidity in He-4 and He-3 can be similarly explained due to the ordering of zero-point fluctuations. Thus it is established that the both related phenomena are based on the same physical mechanism.

B. V. Vasiliev

2010-09-13T23:59:59.000Z

468

Magnetic profiles in ferromagnetic/superconducting superlattices.  

SciTech Connect

The interplay between ferromagnetism and superconductivity has been of longstanding fundamental research interest to scientists, as the competition between these generally mutually exclusive types of long-range order gives rise to a rich variety of physical phenomena. A method of studying these exciting effects is by investigating artificially layered systems, i.e. alternating deposition of superconducting and ferromagnetic thin films on a substrate, which enables a straight-forward combination of the two types of long-range order and allows the study of how they compete at the interface over nanometer length scales. While originally studies focused on low temperature superconductors interchanged with metallic ferromagnets, in recent years the scope has broadened to include superlattices of high T{sub c} superconductors and colossal magnetoresistance oxides. Creating films where both the superconducting as well as the ferromagnetic layers are complex oxide materials with similar crystal structures (Figure 1), allows the creation of epitaxial superlattices, with potentially atomically flat and ordered interfaces.

te Velthuis, S. G. E.; Hoffmann, A.; Santamaria, J.; Materials Science Division; Univ. Complutense de Madrid

2007-02-28T23:59:59.000Z

469

Rotatable superconducting cyclotron adapted for medical use  

DOE Patents (OSTI)

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.

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

1985-01-01T23:59:59.000Z

470

Vital Tool in Superconductivity Studies | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Short Title Neutron scattering continues as a vital tool in superconductivity studies January 01, 2011 In 2008, the totally unexpected discovery of a New class of superconductors,...

471

On superconductivity of high-spin transition metal compounds  

SciTech Connect

The possibility of Cooper instability in transition metal compounds is established based of the concept of the strong interaction in the same unit cell. The multicomponent scattering amplitude of excitations is calculated. The superconductivity equations are derived for compounds of 3d transition metals. It is shown that in the pole approximation, the superconductivity equations can be reduced to the multicomponent superconductivity equations with preset BCS constants. A method is developed for calculating one-orbital constants and constants with different orbitals as functions of the total spin. The concentration ranges of superconducting ordering are obtained for one-orbital equations.

Zaitsev, R. O., E-mail: Zaitsev_rogdai@mail.ru [Moscow Institute of Physics and Technology (State University) (Russian Federation)

2011-11-15T23:59:59.000Z

472

BSA 08-04: High Temperature Interfacial Superconductivity  

Cuprate superconductors exhibit relatively high transition temperatures, but their unit cells are complex and large. Localizing a superconducting layer to a small ...

473

"ONE HUNDRED YEARS OF SUPERCONDUCTIVITY", Dr. Michael Norman...  

NLE Websites -- All DOE Office Websites (Extended Search)

March 10, 2012, 9:30am Science On Saturday "ONE HUNDRED YEARS OF SUPERCONDUCTIVITY", Dr. Michael Norman, Materials Science Division, Argonne National Laboratory http:...

474

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for Electric Systems: 2008 Annual Peer Review Final Report The Office of Electricity Delivery and Energy Reliability's High Temperature Superconductivity (HTS) for...

475

Magnetism and Superconductivity in Ruthenates, Ruthenocuprates, and Other Layered Oxides.  

E-Print Network (OSTI)

??There exist several classes of materials that simultaneously exhibit superconductivity and anomalous magnetic order, where both effects are homogeneous throughout the material. No cohesive explanation… (more)

Smylie, Matthew Passmore

2010-01-01T23:59:59.000Z

476

EFFECTS OF DIMENSIONALITY, SAMPLE TOPOLOGY, AND DISORDER ON SUPERCONDUCTIVITY.  

E-Print Network (OSTI)

??The primary goal of this thesis work is to explore various phenomena related to the effects of dimensionality, sample topology, and disorder on superconductivity, motivated… (more)

Wang, Haohua

2006-01-01T23:59:59.000Z

477

Effects of geometric constraints and sample topology on superconductivity.  

E-Print Network (OSTI)

??The goal of this dissertation is to explore the effects of geometric constraints and sample topology on superconductivity. This work started with an effort to… (more)

Staley, Neal

2012-01-01T23:59:59.000Z

478

Studies in Magnetism and Superconductivity under Extreme Pressure.  

E-Print Network (OSTI)

??Abstract Studies of superconductivity, magnetism and structure under pressure have made important contributions to furthering our understanding of the physical properties of materials. High pressure… (more)

Bi, Wenli

2011-01-01T23:59:59.000Z

479

Type-I superconductivity and neutron star precession  

E-Print Network (OSTI)

Type-I proton superconducting cores of neutron stars break up in a magnetic field into alternating domains of superconducting and normal fluids. We examine two channels of superfluid-normal fluid friction where (i) rotational vortices are decoupled from the non-superconducting domains and the interaction is due to the strong force between protons and neutrons; (ii) the non-superconducting domains are dynamically coupled to the vortices and the vortex motion generates transverse electric fields within them, causing electronic current flow and Ohmic dissipation. The obtained dissipation coefficients are consistent with the Eulerian precession.

Armen Sedrakian

2004-08-25T23:59:59.000Z

480

Superconductivity Efforts at the US Department of Energy (DOE)  

Science Conference Proceedings (OSTI)

The DOE Office of Electricity Delivery and Energy Reliability Superconductivity Program's specific mission is to work in partnership with industry to develop HTS

Note: This page contains sample records for the topic "nanofabricated superconducting rf" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Developing a High-Temperature Superconducting Bulk Magnet for ...  

Science Conference Proceedings (OSTI)

In addition to these well-developed technologies, high-critical temperature superconductors that show superconductivity at liquid nitrogen are also prospective ...

482

Growth and Superconductivity of Pb and Pb-Bi Alloys in the Quantum Regime.  

E-Print Network (OSTI)

??Superconductivity is a collective quantum phenomenon that is inevitably suppressed in reduced dimensionality. Questions of how thin superconducting wires or films can be before they… (more)

Ozer, Mustafa Murat

2006-01-01T23:59:59.000Z

483

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

SciTech Connect

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.

Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Wooldridge, E. [EURATOM/CCFE Fusion Association, Culham Science Centre (United Kingdom)

2011-12-23T23:59:59.000Z

484

Study of lithium diffusion in RF sputtered Nickel/Vanadium mixed oxides thin films  

E-Print Network (OSTI)

Study of lithium diffusion in RF sputtered NickelÁ/Vanadium mixed oxides thin films F. Artuso a lithium insertion inside RF sputtered Ni/V mixed oxides thin films have been investigated employing, showed three steps clearly involved in the intercalation mechanism of lithium in the oxide films: (i

Artuso, Florinda

485

RF propagation in an HVAC duct system: impulse response characteristics of the channel  

E-Print Network (OSTI)

RF propagation in an HVAC duct system: impulse response characteristics of the channel Pavel V, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow at RF and microwave frequencies of com- mon interest. HVAC ducts can be used as a wireless communication

Stancil, Daniel D.

486

RF Breakdown Studies Using a 1.3 GHZ Test Cell  

DOE Green Energy (OSTI)

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. Recent studies have shown that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas without the need for long conditioning times, because the dense gas can dramatically reduce dark currents and multipacting. In this project we use this high pressure technique to suppress effects of residual vacuum and geometry found in evacuated cavities to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. A 1.3-GHz RF test cell with replaceable electrodes (e.g. Mo, Cu, Be, W, and Nb) and pressure barrier capable of operating both at high pressure and in vacuum has been designed and built, and preliminary testing has been completed. A series of detailed experiments is planned at the Argonne Wakefield Accelerator. At the same time, computer simulations of the RF Breakdown process will be carried out to help develop a consistent physics model of RF Breakdown. In order to study the effect of the radiofrequency on RF Breakdown, a second test cell will be designed, fabricated, and tested at a lower frequency, most likely 402.5 MHz.

Sah, R.; Johnson, R.P.; Neubauer, M.; /Muons Inc., Batavia; Conde, M.; Gai, W.; /Argonne; Moretti, A.; Popovic, M.; Yonehara, K.; /Fermilab; Byrd, J.; Li, D.; /LBL, Berkeley; BastaniNejad, M.; /Old Dominion U.

2009-05-01T23:59:59.000Z

487

RF Breakdown Studies Using a 1.3-GHz Text Cell  

DOE Green Energy (OSTI)

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. Recent studies have shown that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas without the need for long conditioning times, because the dense gas can dramatically reduce dark currents and multipacting. In this project we use this high pressure technique to suppress effects of residual vacuum and geometry found in evacuated cavities to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. A 1.3-GHz RF test cell with replaceable electrodes (e.g. Mo, Cu, Be, W, and Nb) and pressure barrier capable of operating both at high pressure and in vacuum has been designed and built, and preliminary testing has been completed. A series of detailed experiments is planned at the Argonne Wakefield Accelerator. At the same time, computer simulations of the RF Breakdown process will be carried out to help develop a consistent physics model of RF Breakdown. In order to study the effect of the radiofrequency on RF Breakdown, a second test cell will be designed, fabricated, and tested at a lower frequency, most likely 402.5 MHz.

Sah, R.; Johnson, R. P.; Neubauer, M.; Conde, M.; Gai, W.; Moretti, A.; Popovic, M.; Yonehara, K.; Byrd, J.; Li, D.; BastaniNejad, M.; Elmustafa, M.

2009-05-04T23:59:59.000Z

488

Active RF Pulse Compression Using An Electrically Controlled Semiconductor Switch  

SciTech Connect

First we review the theory of active pulse compression systems using resonant delay lines. Then we describe the design of an electrically controlled semiconductor active switch. The switch comprises an active window and an overmoded waveguide three-port network. The active window is based on a four-inch silicon wafer which has 960 PIN diodes. These are spatially combined in an overmoded waveguide. We describe the philosophy and design methodology for the three-port network and the active window. We then present the results of using this device to compress 11.4 GHz RF signals with high compression ratios. We show how the system can be used with amplifier like sources, in which one can change the phase of the source by manipulating the input to the source. We also show how the active switch can be used to compress a pulse from an oscillator like sources, which is not possible with passive pulse compression systems.

Guo, Jiquan; Tantawi, Sami; /SLAC

2007-01-10T23:59:59.000Z

489

GaAs Films Prepared by RF-Magnetron Sputtering  

DOE Green Energy (OSTI)

The authors reported on the optical absorption, adhesion, and microstructure of RF-magnetron sputtered films of hydrogenated amorphous and microcrystalline GaAs films for the 1 to 25 {micro}m infrared wavelength rate. Sputtering parameters which were varied include sputtering power, temperature and pressure, and hydrogen sputtering-gas concentration. TEM results show a sharp transition from purely amorphous GaAs to a mixture of microcrystalline GaAs in an amorphous matrix at 34 {+-} 2 C. By optimizing the sputtering parameters, the optical absorption coefficient can be decreased below 100 cm{sup -1} for wavelengths greater than about 1.25 {micro}m. These results represent the lowest reported values of optical absorption for sputtered films of GaAs directly measured by spectrophotometry for the near-infrared wavelength region.

L.H. Ouyang; D.L. Rode; T. Zulkifli; B. Abraham-Shrauner; N. Lewis; M.R. Freeman

2001-08-01T23:59:59.000Z

490

A new boson-fermion model of superconductivity  

E-Print Network (OSTI)

It is shown that the superconducting energy gap necessarily lead to the disappearance of some quasi-electrons, thus we suggest a new boson-fermion Hamiltonian to describe superconductivity. The new supercurrent equations are derived with this Hamiltonian. Some new results can be found besides the zero resistance effect, the Meissner effect and the magnetic flux quantum can be explained.

Tian De Cao

2010-10-17T23:59:59.000Z

491

Superconductivity at 35 K in Graphite-Sulfur Composites  

E-Print Network (OSTI)

We report magnetization measurements performed on graphite–sulfur composites which demonstrate a clear superconducting behavior below the critical temperature Tc0 = 35 K. The Meissner-Ochsenfeld effect, screening supercurrents, and magnetization hysteresis loops characteristic of type-II superconductors were measured. The results indicate that the superconductivity occurs in a small sample fraction, possibly related to the sample surface.

R. Ricardo Da Silva; J. H. S. Torres; Y. Kopelevich

2001-01-01T23:59:59.000Z

492

Superconducting magnetic energy storage for asynchronous electrical systems  

DOE Patents (OSTI)

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.

Boenig, H.J.

1984-05-16T23:59:59.000Z

493

Superconducting magnetic energy storage for asynchronous electrical systems  

DOE Patents (OSTI)

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.

Boenig, Heinrich J. (Los Alamos, NM)

1986-01-01T23:59:59.000Z

494

Pressure induced Superconductivity in the Charge Density Wave Compound Tritelluride  

Science Conference Proceedings (OSTI)

A series of high-pressure electrical resistivity measurements on single crystals of TbTe{sub 3} reveal a complex phase diagram involving the interplay of superconducting, antiferromagnetic and charge density wave order. The onset of superconductivity reaches a maximum of almost 4 K (onset) near {approx} 12.4 GPa.

Hamlin, J.J.; Zocco, D.A.; Sayles, T.A.; Maple, M.B.; /UC, Davis; Chu, J.-H.; Fisher, I.R.; /Stanford U., Geballe Lab.

2010-02-15T23:59:59.000Z

495

Proceedings of 8th Annual EPRI Superconductivity Conference  

Science Conference Proceedings (OSTI)

The Electric Power Research Institutes EPRIs Eighth Annual EPRI Superconductivity ConferencePower Delivery Applications for Superconductivitywas held November 1213, 2008 in Oak Ridge, Tennessee at the Doubletree Hotel Oak Ridge. The U.S. Department of Energy DOE and Oak Ridge National Laboratory co-sponsored the event with EPRIs Superconductivity Program. This report contains the papers presented at the conference.

2008-12-23T23:59:59.000Z

496

SLAC collider injector, RF-drive synchronization and trigger electronics, and 15-AMP thermionic-gun development  

SciTech Connect

The rf drive system for the Collider Injector Development (EL CID) including laser timing, subharmonic buncher drive and phasing, and accelerator rf drive is described. The rf synchronized master trigger generation scheme for the collider is outlined. Also, a 15 amp peak, 200 kV short pulse gun being developed at SLAC as a backup to the Sinclair laser gun is described.

Koontz, R.; Miller, R.; McKinney, T.; Wilmunder, A.

1981-02-01T23:59:59.000Z

497

STATEMENT OF CONSIDERATIONS REQUEST BY DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN PATENT RIGHTS UNDER DOE CONTRACT NO. DE-FC36-99GO10287; W(A)-99-008; CH-1002 The Petitioner, DuPont Superconductivity (hereinafter "DuPont"), has requested a waiver of domestic and foreign patent rights for all subject inventions arising from its participation under the above referenced contract entitled "High Temperature Superconducting Reciprocating Magnetic Separator". This contract relates to the construction of 1/4 commercial scale High Temperature Superconducting (hereinafter "HTS") Reciprocating Magnetic Separations Unit for the purification ofkaoline clay and titanium dioxide. It is anticipated that this project will be performed in three phases, over a period of