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in creator/contributor: "Coulter, J. Y."

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Enhanced Critical Currents in Bi-2223/Ag Sheathed Tapes by High Energy Proton Irradiation

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Date: July 1, 2001

Creator: Willis, J. O.; Coulter, J. Y. & AL, ET

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

HTS High Gradient Magnetic Separation system

We report on the assembly, characterization and operation of a high temperature superconducting (HTS) magnetic separator. The magnet is made of 624 m of Silver/BSCCO superconducting wire and has overall dimensions of 18 cm OD, 15.5 cm height and 5 cm ID. The HTS current leads are designed to operate with the warm end at 75 K and the cold end cooled by a two stage Gifford-McMahon cryocooler. The upper stage of the cryocooler cools the thermal shield and two heat pipe thermal intercepts. The lowe… more

Date: September 1, 1996

Creator: Daugherty, M. A.; Coulter, J. Y. & Hults, W. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Magnetic field and field orientation dependence of the critical current density in Bi-2212 round wires and other HTS conductors

The authors have performed measurements of the magnetic field dependence of the critical current density J{sub c} of Bi-2212/Ag round wire produced by isothermal melt processing. In contrast to the case for flat tape, there is very little dependence of J{sub c} on the direction of the magnetic field as it is rotated normal to the wire axis, which is the direction of the nominal current flow. However, when the angle of the magnetic field direction is rotated from normal to the wire axis to paral… more

Date: October 1, 1996

Creator: Willis, J. O.; Holesinger, T. G.; Coulter, J. Y. & Maley, M. P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Measurement Of Transverse Jc Profiles Of Coated Conductors Using A Magnetic Knife Of Permanent Magnets

The transverse J{sub c} distribution in YBCO coated conductors was measured nondestructively with high resolution using a 'magnetic knife' made of permanent magnets. The method utilizes the strong depression of J{sub c} in applied magnetic fields. A narrow region of low (including zero) magnetic field, in a surrounding higher field, is moved transversely across the sample in order to reveal the critical-current density distribution. The net resolution of this device is approximately 65 {mu}m, a… more

Date: January 1, 2008

Creator: Hanisch, J; Mueller, F. M.; Ashworth, S P; Coulter, J Y & Matias, Vlad

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Processing of YBCO/IBAD YSZ coated conductors on flexible substrates

Continuous coaters capable of producing 1.1 m long x 1 cm wide tapes of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) on biaxially oriented yttria-stabilized zirconia (YSZ) on flexible Ni-alloy substrates have been developed at this laboratory. Using a 1 {micro}V/cm criterion, the authors have achieved transport critical current (I{sub c}) values of 29 A (75 K, self field) between voltage taps spaced 1 m apart. The corresponding critical current density (J{sub c}) value for this tape is 290 … more

Date: December 1, 1998

Creator: Arendt, P. N.; Foltyn, S. R.; Dowden, P. C.; Groves, J. R.; DePaula, R. & Coulter, J. Y.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Anisotropy of the critical current density in Bi-2223/Ag tapes

The effect of thermomechanical processing on texture in Bi-2223 Ag-sheathed tapes as determined from the anisotropy of the critical current density J{sub c} in an applied magnetic field will be discussed. Model calculations for a distribution of grain orientations in the tape produce good fits to the data and allow characterization of the degree of long-range texture. There is a qualitative correlation of J{sub c} with global texture, but other factors, such as intergrain connectivity, are also… more

Date: May 1, 1994

Creator: Willis, J. O.; Coulter, J. Y.; Maley, M. P.; Daemen, L. L.; Rupich, M. W. & Riley, G. N. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Single-phase ac losses in prototype HTS conductors for superconducting power transmission lines

The authors report single-phase ac loss measurements on 8, 4, and 3-layer, multi-strand, HTS prototype conductors for power transmission lines. They use both calorimetric and electrical techniques. The agreement between the two techniques suggests that the interlayer current distribution in one-meter long conductors are representative of those in long conductors. The losses for the 8 and 4-layer conductors are in rough agreement, with the 8-layer losses being somewhat lower. The 3-layer conduct… more

Date: December 1, 1998

Creator: Daney, D. E.; Maley, M. P.; Boenig, H. J.; Willis, J. O.; Coulter, J. Y.; Gherardi, L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Anisotropic high temperature superconductors as variable resistors and switches

Several anisotropic high temperature superconductors show critical current densities which are strongly dependent on the direction of an applied external magnetic field. The resistance of a sample can change by several orders of magnitude by applying a magnetic field. The potential for using the field dependent variable resistor or switch for applications in power systems is evaluated. Test results with small samples are presented. The requirements for large scale applications are outlined. The… more

Date: December 1, 1994

Creator: Boenig, H. J.; Daugherty, M. A.; Fleshler, S.; Maley, M. P.; Mueller, F. M.; Prenger, F. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Magnetic hysteresis and relaxation in Ag-sheathed TlBaCaCuO (1223) and Bi(Pb)SrCaCuO (2223) superconducting tapes

Magnetic hysteresis (7--75 K in magnetic fields up to 5 T) and relaxation characteristics (5--50 K in magnetic fields up to 2 T) have been measured with the field perpendicular to the surface of Ag-sheathed TlBaCaCuO (1223 phase) and Bi(Pb)SrCaCuO (2223 phase) superconducting tapes. A study of the difference in the magnetic hysteresis between precursor powders and as-processed tapes was also carried out. The relaxation data were curve-fit using a rate equation for thermally activated flux motio… more

Date: January 1, 1992

Creator: Kung, P. J.; Maley, M. P.; Coulter, J. Y.; Willis, J. O.; Peterson, D. E.; McHenry, M. E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Magnetic hysteresis and relaxation in Ag-sheathed TlBaCaCuO (1223) and Bi(Pb)SrCaCuO (2223) superconducting tapes

Date: May 1, 1992

Creator: Kung, P. J.; Maley, M. P.; Coulter, J. Y.; Willis, J. O.; Peterson, D. E.; McHenry, M. E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High-temperature superconducting conductors and cables

This is the final report of a 3-year LDRD project at LANL. High-temperature superconductivity (HTS) promises more efficient and powerful electrical devices such as motors, generators, and power transmission cables; however this depends on developing HTS conductors that sustain high current densities J{sub c} in high magnetic fields at temperatures near liq. N2`s bp. Our early work concentrated on Cu oxides but at present, long wire and tape conductors can be best made from BSCCO compounds with … more

Date: September 1996

Creator: Peterson, D. E.; Maley, M. P.; Boulaevskii, L.; Willis, J. O.; Coulter, J. Y.; Ullmann, J. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Single and three-phase AC losses in HTS superconducting power transmission line prototype cables

AC losses in two, one-meter-long lengths of HTS prototype multi-strand conductors (PMC`s) are measured with a temperature-difference calorimeter. Both single-phase and three-phase losses are examined with ac currents up to 1,000 A rms. The calorimeter, designed specifically for these measurements, has a precision of 1 mW. PMC {number_sign}1 has two helically-wound, non-insulated layers of HTS tape (19 tapes per layer), each layer wrapped with opposite pitch. PMC {number_sign}2 is identical exce… more

Date: November 1, 1997

Creator: Daney, D. E.; Boenig, H. J.; Maley, M. P.; Coulter, J. Y. & Fleshler, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Transport and magnetization critical current densities in TlBa sub 2 Ca sub 2 Cu sub 3 O sub x tapes

The powder in tube process was used to produce silver-sheathed tapes of TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+x} (Tl-1223). The powder was produced by thalliating a precursor powder mixture to produce the Tl-2223 phase and then beating to drive off excess Tl and reach the Tl-1223 stoichiometry. The tapes were rolled and pressed, each step followed with a 3 h sintering. The 200 {mu}m thick tapes show little sign of texturing; however, the critical current shows a small ({approximately}50%) depend… more

Date: January 1, 1992

Creator: Willis, J. O.; Maley, M. P.; Kung, P. J.; Coulter, J. Y.; Peterson, D. E.; Wahlbeck, P. G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Transport and magnetization critical current densities in TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes

Date: October 1, 1992

Creator: Willis, J. O.; Maley, M. P.; Kung, P. J.; Coulter, J. Y.; Peterson, D. E.; Wahlbeck, P. G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Preparation of high quality YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thick films on flexible Ni-based alloy substrates with textured buffer layers

High current YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) thick films on flexible nickel substrates with textured buffer layers were deposited by using ion beam assisted deposition (IBAD). Pulsed laser deposited YBCO films were not only c-axis oriented with respect to the film surface but also strongly in-plane textured. The in-plane mosaic spread of YBCO films was {approximately} 10{degrees}. A critical current density of 8x10{sup 5} A/cm{sup 2} was obtained at 75 K and zero field for thin YBCO … more

Date: December 31, 1995

Creator: Wu, X. D.; Foltyn, S. R.; Arendt, P.; Townsend, J.; Campbell, I. H.; Tiwari, P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The influence of structural defects on intragranular critical currents of bulk MgB[sub 2].

Bulk MgB2 samples were prepared under different synthesis conditions and analyzed by scanning and transmission electron microscopy. The critical current densities were determined from the magnetization versus magnetic field curves of bulk and powder-dispersed-in-epoxy samples. Results show that through a slow cooling process, the oxygen dissolved in bulk MgB2 at high synthesis temperatures can segregate and form nanometer-sized coherent precipitates of Mg(B,O)2 in the MgB2 matrix. Magnetization… more

Date: January 1, 2002

Creator: Serquis, A. (Adriana); Liao, Xiaozhou; Civale, L. (Leonardo); Zhu, Y. T. (Yuntian Theodore); Coulter, J. Y. (James Y.); Peterson, D. E. (Dean E.) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Microstructural development and control in YBa[sub 2]Cu[sub 3]O[sub y]

A study of some defect structures in Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} (Y-123)coated conductors based on ion-beam -assisted-deposition (IBAD) of yttria-stabilized zirconia (YSZ) on nickel alloy substrates is presented. Defect structures can originate anywhere in the coated conductor architecture. Defects can be additive and propagate through the entire film structure to affect the growth, orientation, arid properties of the superconducting film. Interfacial Ieactions between Y- 123 and the und… more

Date: January 1, 2001

Creator: Holesinger, T. G. (Terry G.); Gibbons, B. J. (Brady J.); Foltyn, S. R. (Stephen R.); Arendt, P. N. (Paul N.); Groves, J. R. (James R.) & Coulter, J. Y. (James Y.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High-Tc Coated Conductors - Performance of Meter-Long YBCO/IBAD Flexible Tapes

One meter long tapes based on 50-100 {micro}m thick by 1 cm wide nickel alloy substrates have been coated in a continuous process with a textured yttria-stabilized zirconia layer by ion beam-assisted deposition, followed by a 1-2 {micro}m thick layer of YBCO by pulsed laser deposition. The best result to date is a tape with a critical current (I{sub c}) at 75 K of 96 A over an 87 cm measurement length. The overall critical current density and engineering current density are 1 MA/cm{sup 2} and 1… more

Date: September 13, 1998

Creator: Foltyn, S. R.; Arendt, P. N.; Dowden, P. C.; DePaula, R. F.; Groves, J. R.; Coulter, J. Y. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characterizing transport current defects in 1-cm-wide YBa[sub 2]Cu[sub 3]O[sub 7-delta] coated conductors.

We have used a low temperature magnetic imaging system to determine current pathways in 5 cm long 'good' and 'bad' regions of a 1-cm-wide YBa2Cu3O7-{delta} coated conductor. The good and bad regions were identified with 4 point probe measurements taken at 1 cm intervals along the tape length. The current density map from the good region showed the expected edge peaked structure, similar to that seen in previous work on high quality test samples grown on single crystal substrates. The structure … more

Date: January 1, 2001

Creator: Brown, G. W. (Geoffrey W.); Hawley, M. E. (Marilyn E.); Peterson, E. J. (Eric J.); Coulter, J. Y. (James Y.); Dowden, P. C. (Paul C.); Arendt, P. N. (Paul N.) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department