Performance tests of Bi-2223 pancake magnet

Kumakura, Hiroaki; Kitaguchi, Hitoshi; Togano, K.; Wada, Hitoshi; Ohkura, K.; Ueyama, M.; Hayashi, Kazuhiko; Sato, K.

doi:10.1016/s0011-2275(98)00040-x

Cited by 21 publications

(28 citation statements)

References 3 publications

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“…Therefore, analyzing ∂Ε/∂J (or ∂Τ/∂J) it is easy to find the stable and unstable operating thermo-electrodynamics states under the applied conditions. Accordingly, the boundary between them is defined by condition ∂Ε/∂J→∞ (18) For the first time, this condition was formulated in [14] for low-T c superconductors cooled by a coolant with the constant coefficient of heat transfer. This cooling mode is characteristic of the conduction-cooled or gas-cooled superconductors.…”

Section: Zero-dimensional Approximation Of Applied Current Instabilitymentioning

confidence: 99%

“…Under the equality (17) and condition (18), the boundary of the instability is determined by the so-called quench values of the electric field E q,0 , current I q,0 and temperature T q,0 . They are equal to ( )…”

Section: Zero-dimensional Approximation Of Applied Current Instabilitymentioning

confidence: 99%

“…In this case, the macroscopic electrodynamics of superconductor is a consequence of the non-*Address correspondence to this author at the National Research Center "Kurchatov Institute", NBIK-center, 123182 Moscow, Russia; Fax: 7 (499) 1965973; Tel: 7 (499) 1969600; E-mail: vromanovskii@netscape.net local dynamics of vortex lattice that is gradually coming to the motion [13]. The concept of the resistive states significantly expands the range of permissible stable operating mode of high-T c superconducting materials [14][15][16][17][18][19][20][21][22][23]. However, they are characterized by non-trivial temperature change of superconductor, which depends on the electrodynamics processes in superconductor.…”

Section: Introductionmentioning

confidence: 99%

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Thermal Mechanisms of Stable Macroscopic Penetration of Applied Currents in High Temperature Superconductors and their Instability Conditions

Romanovskii¹

2012

TOAPJ

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Macroscopic mechanisms of applied current penetration in high-T c superconductors are discussed to understand the basic physical trends, which are characteristic for the stable and unstable formation of the thermo-electrodynamics states of high-T c superconductors placed in DC external magnetic field. The performed analysis shows that the definition of the current stability conditions of high-T c superconductors must take into consideration the development of the interconnected thermal and electrodynamics states when the temperature of superconductor may stably rise before instability. As a result, the thermal degradation effect of the current-carrying capacity of superconductor exists. The boundary values of the electric field and the current above which the applied current is unstable are defined taking into account the size effect, cooling conditions, non-linear temperature dependences of the critical current density of superconductor. It is proved that the allowable stable values of electric field and current can be both below and above those determined by a priori chosen critical values of the electric field and current of the superconductor. The violation features of the stable current distribution in high-T c superconductors cooled by liquid coolant are studied. The necessary criteria allowing one to determine the influence of the properties of superconductor and coolant on the current instability onset are written.

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Section: Zero-dimensional Approximation Of Applied Current Instabilitymentioning

confidence: 99%

Section: Zero-dimensional Approximation Of Applied Current Instabilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermal Mechanisms of Stable Macroscopic Penetration of Applied Currents in High Temperature Superconductors and their Instability Conditions

Romanovskii¹

2012

TOAPJ

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“…Tufnol was chosen primarily because of its electrically insulating properties and ease of use but also due to its adequate fracture stress and similar thermal contraction to epoxy. Copper and other metallic based materials have been used with the advantages of higher thermal conductivity and high strength which can be important in large magnets [7,15,16]. Ceramic formers are used in W + R magnets due to their refractory properties [6,32].…”

Section: Magnet Windingsmentioning

confidence: 99%

“…Laboratory-scale magnets have been produced using both the 'react-and-wind' (R + W) and 'wind-and-react' (W + R) processes. Using R + W, 1 T has been generated [15] from eight R + W double-wound pancakes at 4.2 K. At 20 K, 1.1 T was achieved from 17 R + W double-wound pancakes [16]. Using W + R, a Bi-2223 coil with a 15 mm bore generated a field of 1.34 T at 4.2 K [17] and Bi-2212 inserts have produced 2.6 T in a self-field and 1.08 T in a background of 20 T at 4.2 K [18].…”

Section: Introductionmentioning

confidence: 99%

Design, fabrication and performance of a 1.29 T Bi-2223 magnet

Sneary

Friend²,

Hampshire

2001

Supercond. Sci. Technol.

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The design and fabrication procedure of a laboratory-scale Bi-2223 tape superconducting magnet with a bore of 40 mm and a maximum field of 1.29 T at 4.2 K is presented. The magnet comprises six resin impregnated double-wound pancakes of bore diameter 40 mm fabricated via the react-and-wind route. Critical current density (J c ) measurements have been made as a function of magnetic field, angle and strain at 4.2 K and 77 K on short samples. In zero field, the critical current density for the superconducting cross-sectional area of the tape was 8.3 × 10 4 A cm −2 (4.2 K) and 1.18 × 10 4 A cm −2 (77 K). The electric field-current density characteristics of all the components of the coils when individually energized or with the whole magnet energized have been measured. Comparison between short sample measurements and performance of the magnet show that minimal additional damage occurred beyond the ∼20% that was produced by the bending strain during the wind-and-react fabrication procedure and the ∼10% variation of the long length J c of the tape. Sufficient detail is provided for the non-specialist to assess both the use of potential brittle superconducting tapes for magnet technology and to construct a laboratory-scale magnet.

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