Critical Current, Critical Temperature and Magnetic Field Based EMTDC Model Component for HTS Power Cable

The results of calculating the temperature dependences of the critical current density and critical magnetic field of thin inhomogeneous superconducting films are presented. Comparison of the results obtained for inhomogeneous films with the results of calculations for homogeneous ones showed that in both cases, the decrease in the critical magnetic field occurs according to the root law, and the critical current density changes according to a power law with a degree of 3/2 when approaching the critical temperature. Quantitatively, the critical current density for inhomogeneous films in the absence of an external magnetic field is lower than for homogeneous ones. In turn, the critical magnetic field of inhomogeneous films is much larger than the critical field of homogeneous films.

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Features of the temperature dependence and magnetic-field dependence of the critical current density close to the critical temperature in YBa2Cu3O7−δ thin films

Low Temperature Physics ◽

10.1063/1.3292940 ◽

2010 ◽

Vol 36 (1) ◽

pp. 81-91 ◽

Cited By ~ 2

Author(s):

D. G. Kovalchuk ◽

M. P. Chornomorets ◽

S. M. Ryabchenko ◽

E. A. Pashitskii ◽

A. V. Semenov

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Critical Temperature ◽

Critical Current Density ◽

Temperature Dependence ◽

Critical Current ◽

Field Dependence ◽

Current Density ◽

Magnetic Field Dependence

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Gamma Radiation Effects on Some Properties of YBCO

MRS Proceedings ◽

10.1557/proc-209-861 ◽

1990 ◽

Vol 209 ◽

Author(s):

L. Luo ◽

Y.H. Zhang ◽

S.H. Hu ◽

W.H. Liu ◽

G.L. Chang ◽

...

Keyword(s):

Magnetic Field ◽

Critical Temperature ◽

Critical Current ◽

Irradiation Dose ◽

Radiation Effects ◽

Bulk Sample ◽

Critical Currents ◽

Zero Magnetic Field ◽

Spectra Analysis ◽

Γ Ray

ABSTRACTRadiation effects of polycrystalline YBCO bulk sample irradiated by 60Co γ-rays from a dose of 1x106 up to 7.5×l09 rad at room temperature on critical temperature and critical current were investigated. IR spectrum was also used to study the mechanism of the irradiation. A considerable dependence of these parameters upon irradiation dose was observed. No significant effects on critical temperature were found, but the critical current in zero magnetic field changed greatly. It shows a tendency to decrease with the increase of the irradiation dose except for a slight increase with the dose less than about 2×107 rad and no simple relations between critical currents and irradiation doses was found. A typical case is that the critical current is reduced to about 60% when the dose reaches 5×109 rad, but the dependence of critical currents on magnetic field shows that the critical currents are higher than that of the unirradiated one in the range of magnetic field higher than 100 Gauss and decrease more slowly in magnetic field compared with the unirradiated one. The results indicate that the defects produced by γ-ray irradiation are benefit to flux pinning in higher fields. IR spectra analysis reveals that the intensity of the peak responsible for the Cul-O1 chain vibration is decreased, indicating that the bond of the Cul-O1 may be partly broken through collision process of the Compton electron produced by the γ-ray. This effect probably gives rise to decrease of the critical currents.

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Theoretical Derivation of Critical Current Density and Critical Magnetic Field Considering Many-Body Interactions of Magnetic Flux Quanta

10.20944/preprints202105.0227.v1 ◽

2021 ◽

Author(s):

Shinichi Ishiguri

Keyword(s):

Magnetic Field ◽

Critical Temperature ◽

Magnetic Flux ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Critical Magnetic Field ◽

Many Body ◽

Magnetic Flux Quantum ◽

Many Body Interactions

To clarify the relationships among critical temperature, critical magnetic field, and critical current density, this paper describes many-body interactions of quantum magnetic fluxes (i.e., vortices) and calculates pinning-related critical current density. All calculations are analytically derived, without numerical or fitting methods. After calculating a magnetic flux quantum mass, we theoretically obtain the critical temperature in a many-body interaction scenario (which can be handled by our established method). We also derive the critical magnetic field and inherent critical current density at each critical temperature. Finally, we determine the pinning-related critical current density with self-fields. The relationships between the critical magnetic field and critical temperature, inherent critical current density and critical temperature, and pinning critical current density and self-magnetic field were consistent with experimental observations. From the critical current density and critical magnetic field, we clarified the magnetic field transition. It appears that a magnetic flux quantum collapses when the lattice of magnetic flux quanta melts. Our results, combined with our previously published papers, provide a comprehensive understanding of the transition points in high-Tc cuprates.

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