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.

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?’.

SELF-MAGNETIZATION IN ELECTROWEAK VACUUM AND IN VERY DENSE SYSTEMS

2011 ◽  
Vol 20 (supp02) ◽  
pp. 168-175
Author(s):  
HUGO PÉREZ ROJAS ◽  
ELIZABETH RODRÍGUEZ QUERTS
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
External Field ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
W Bosons ◽  
Large Density ◽  
Electron Positron ◽  
Vector Bosons ◽  
The Magnetic Field

For charged vector bosons (W bosons) of mass mw, magnetization diverges for B → Bcw, which suggests that if the magnetic field is large enough, it can be self-consistently maintained. For photons bearing an anomalous magnetic moment, having a sufficiently large density, their contribution to magnetization might become of the same order than the applied external field, leading also to self-magnetization. We discuss these models in connection to the case of radiation in equilibrium at high temperature (T ~ mc2) coexisting with hot magnetized electron-positron pairs.

scholarly journals Design Development and Analysis of a Partially Superconducting Axial Flux Motor Using YBCO Bulks

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4295
Author(s):  
Brahim Chelarem Douma ◽  
Bilal Abderezzak ◽  
Elhadj Ailam ◽  
Raluca-Andreea Felseghi ◽  
Constantin Filote ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Low Temperature ◽  
Magnetic Flux ◽  
Power Density ◽  
Theoretical Study ◽  
Design Development ◽  
Axial Flux ◽  
Flux Concentration ◽  
The Magnetic Field

In this work, authors have designed, constructed and tested a new kind of partially superconducting axial flux machine. This model is based on the magnetic flux concentration principle. The magnetic field creation part consists of the NbTi superconducting solenoid and two YBaCuO plates. A theoretical study is conducted of an extrapolated superconducting inductor for low-temperature superconducting and high-temperature superconducting solenoids. The optimization of the inductor is carried out in order to increase the torque and the power density as well. This improvement is done by changing the shape of the elements which form the superconducting inductor. Finally, a prototype is realized, and tested.

scholarly journals Механизм формирования критического тока высокотемпературных сверхпроводников, содержащих сквозные микроскопические дефекты

2021 ◽  
Vol 63 (1) ◽  
pp. 65
Author(s):  
А.Н. Максимова ◽  
В.А. Кашурников ◽  
А.Н. Мороз ◽  
И.А. Руднев
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Flux ◽  
Critical Current ◽  
High Temperature Superconductor ◽  
Physical Mechanism ◽  
Characteristic Size ◽  
Pinning Centers ◽  
The Magnetic Field ◽  
Qualitative Picture

The critical current of a model high-temperature superconductor (HTSC) with defects in the form of through holes (antidots) with a characteristic size greater than or of the order of the penetration depth of the magnetic field is calculated. To do this, the subprocesses equivalent to the trapping of the magnetic flux by the hole and the creation of a vortex at the edge of the hole are introduced into the model of layered HTSC. It is shown that accounting for these subprocesses leads to the appearance of a physical mechanism that allows us to correctly describe the non-monotonic dependence of the critical current on the characteristic size of the antidot, similar to that observed in the experiment. Calculations were performed for a pure superconductor and a superconductor containing nanoscale pinning centers. It is shown that the presence of nanoscale pinning centers along with antipoints does not change the qualitative picture of the influence of the antidot radius on the pinning character of the magnetic flux and the behavior of the critical current in the HTSC.

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 Pseudogap Isotope Effect as a Probe of Bipolaron Mechanism in High Temperature Superconductors

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4973
Author(s):  
Victor D. Lakhno
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Isotope Effect ◽  
High Temperature Superconductors ◽  
Translation Invariant ◽  
Pseudogap Phase ◽  
The Magnetic Field

A theory of a pseudogap phase of high-temperature superconductors where current carriers are translation invariant bipolarons is developed. A temperature of T* a transition from a pseudogap phase to a normal one is calculated. For the temperature of a transition to the pseudogap phase, the isotope coefficient is found. It is shown that the results obtained, in particular, the possibility of negative values of the isotope coefficient, are consistent with the experiment. New experiments on the influence of the magnetic field on the isotope coefficient are proposed.

Effect of Cu-O layer spacing on the magnetic field induced resistive broadening of high-temperature superconductors

1991 ◽  
Vol 177 (4-6) ◽  
pp. 431-437 ◽  
Author(s):  
D.H. Kim ◽  
K.E. Gray ◽  
R.T. Kampwirth ◽  
J.C. Smith ◽  
D.S. Richeson ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductors ◽  
Layer Spacing ◽  
The Magnetic Field

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.

Sign in / Sign up

Export Citation Format

Share Document