On the Resistive State of High Temperature Superconductors in Magnetic Field

1989 ◽  
Vol 169 ◽  
Author(s):  
Y. Iye ◽  
S. Nakamura ◽  
T. Tamegai ◽  
T. Terashima ◽  
Y. Bando
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Epitaxial Film ◽  
High Temperature Superconductors ◽  
Experimental Studies ◽  
Transport Current ◽  
Resistive State ◽  
Flux Dynamics ◽  
The Magnetic Field ◽  
Peculiar Behavior

AbstractExperimental studies of the resistive state of high temperature superconductors in the mixed state were carried out on thin film samples of YBa2Cu3O7‐y and Bi2Sr2CaCu2Os+y. Precise angular dependence measurements on Yba2Cu3O7‐y epitaxial film have revealed not only the critical field anisotropy with respect to the a, b, and c‐axes but also a feature associated with twin boundaries. Dependence on the angle between the transport current and the magnetic field is investigated and discussed in terms of flux dynamics in highly anisotropic layered superconductors. Peculiar behavior of the Hall effect in the resistive state is reported.

scholarly journals Measurements and Analysis of AC Losses in HTS Windings of Electrical Machine for Different Operation Modes

2021 ◽  
Vol 11 (6) ◽  
pp. 2741
Author(s):  
Sergey Zanegin ◽  
Nikolay Ivanov ◽  
Vasily Zubko ◽  
Konstantin Kovalev ◽  
Ivan Shishov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
High Temperature Superconductors ◽  
Transport Current ◽  
Operating Conditions ◽  
Ac Losses ◽  
Electrical Machine ◽  
2Nd Generation ◽  
Motor Mode

The article is devoted to the study of losses in devices based on high-temperature superconductors of the 2nd generation. The complexity of the devices under study increases from a single rack coil to a winding assembled from several coils, and finally to an electric machine operating in generator mode. This is the way to experimentally study the behavior of 2nd generation high temperature superconductor (2G HTS) carrying a transport current in various conditions: self-field, external DC, and AC magnetic field. Attention is also paid to the losses in the winding during its operation from the inverter, which simulates the operating conditions in the motor mode of a propulsion system.

Small, modular and economically attractive fusion enabled by high temperature superconductors

2019 ◽  
Vol 377 (2141) ◽  
pp. 20180354 ◽  
Author(s):  
Dennis Whyte
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Fields ◽  
Current Density ◽  
High Temperature Superconductors ◽  
Fusion Energy ◽  
High Magnetic Fields ◽  
Operating Temperatures ◽  
The Magnetic Field ◽  
Game Changer

The advantages of high magnetic fields in tokamaks are reviewed, and why they are important in leading to more compact tokamaks. A brief explanation is given of what limits the magnetic field in a tokamak, and why high temperature superconductors (HTSs) are a game changer, not just because of their higher magnetic fields but also for reasons of higher current density and higher operating temperatures. An accelerated pathway to fusion energy is described, defined by the SPARC and ARC tokamak designs. This article is part of a discussion meeting issue ‘Fusion energy using tokamaks: can development be accelerated?’.

Specific features of penetration and trapping of a magnetic flux in film and bulk YBCO high-temperature superconductors

2018 ◽  
Vol 32 (31) ◽  
pp. 1850346
Author(s):  
Kh. R. Rostami
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Flux ◽  
External Field ◽  
High Temperature Superconductors ◽  
Interaction Mechanism ◽  
Differential Method ◽  
Bulk Ybco ◽  
The Magnetic Field ◽  
Insight Into

An oscillatory differential method of local diagnostics of superconductors is applied to the analysis of the trapped magnetic flux and the effective demagnetization factor in YBCO samples. Regular steps over certain intervals of the external field are observed on the magnetic-field dependence of these parameters. It is demonstrated that, as the external field increases, crystallites in a sample are decomposed into sub- and nanocrystallites with a size much less than the penetration depth [Formula: see text] of the magnetic field. The first critical thermodynamic magnetic fields of sub- and nanocrystallites are determined. These results allow one to reveal the interaction mechanism between magnetic and crystalline microstructures of superconductors and provide a deeper insight into the physical processes that occur in high-temperature superconductors (HTSCs) in a magnetic field.

Transport Properties over Critical Currents for Ag-Sheathed Bi2Sr2CaCu2O8 Superconductors with Different E-J Dependence

2006 ◽  
Vol 47 ◽  
pp. 118-123 ◽  
Author(s):  
K. Watanabe ◽  
T. Inoue ◽  
Satoshi Awaji ◽  
Gen Nishijima ◽  
Ken Ichiro Takahashi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Treatment ◽  
High Temperature ◽  
Electric Field ◽  
Current Density ◽  
High Temperature Superconductors ◽  
Grain Morphology ◽  
Critical Currents ◽  
Heat Treated ◽  
The Magnetic Field

The current-carrying properties beyond a critical current determined by a voltage criterion for Ag-sheathed Bi2Sr2CaCu2O8 (Ag/Bi2212) superconductors are examined at 10 K and 20 K in magnetic fields. We prepared the in-field heat-treated Ag/Bi2212 wires, in order to obtain the magnetic field alignment microstructure for Ag/Bi2212. The electric field and current density (E-J) properties were evaluated for Ag/Bi2212 wires with and without the in-field heat-treatment. We found that the E-J properties for the in-field heat-treated Ag/Bi2212 wires differ from those for the out-of-field heat-treated ones, and are analogous to the E-J dependence for Bi-system high temperature superconductors with the sintered-like grain morphology.

scholarly journals Levitation and Lateral Stabilization Device Based on a Second-Generation High-Temperature Superconductor

2019 ◽  
Vol 5 (4) ◽  
pp. 115-123
Author(s):  
Yuri F. Antonov
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
Second Generation ◽  
Permanent Magnets ◽  
Transport Current ◽  
Critical Parameters ◽  
Technical Solution ◽  
The Magnetic Field ◽  
Superconducting Levitation

The superconducting levitation device comprises a stationary magnetic rail of permanent magnets and a cryostat on a vehicle with a second-generation high-temperature tape superconductor placed in the cryostat, folded in a stack or wound by a coil on a non-magnetic frame without electrical connection of the ends and the transport current. Cool tape high-temperature superconductor of the second generation, folded in a stack or wound on a non magnetic frame in the form of axisymmetric or track coil, without electric connections of the ends and a transport current, behaves as a massive sample of a superconductor and the Meissner Oxenfeld effect, the magnetic field created by the magnetic rail is displaced from the volume of the superconductor, causing the power of levitation and the vehicle hangs over the track structure. The high critical parameters of the second-generation high-temperature superconductor belt ensure efficient operation of the superconducting levitation device. Aim: To demonstration the technical feasibility and efficiency of creating a levitation unit based on the use of a second-generation high-temperature superconductor and permanent magnets made of rare earth metals. Methods: Calculations of the magnetic field distribution in the combination of a magnetic rail and a massive superconductor, preliminary design of the levitation unit and experimental studies on the model. Results: Experiments on a model of a superconducting levitation device confirmed the efficiency of this technical solution and its effectiveness. Conclusion: an original technical solution is proposed that allows to significantly improve the energy characteristics of the levitation node by using a second-generation high-temperature superconductor operating in a passive mode without a transport current, using the partial Meissner-Oxenfeld effect and the engagement of quantized magnetic flux strands at the pinning centers.

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