A constitutive relation for hysteresis in superconductors

Journal Article · Fri Feb 15 04:00:00 EST 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.348725· OSTI ID:5695258

Hodgdon, M L ^[1]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (US)

A constitutive relation consisting of a differential equation {ital {dot B}}={alpha}{vert bar}{ital {dot H}}{vert bar}( {ital f}({ital H}){minus}{ital B})+{ital {dot H}g}({ital H}), where {ital {dot H}} is nonzero, and an experimentally determined condition imposed at the points where {ital {dot H}} changes sign is shown to provide a remarkably good and useful representation of hysteresis in superconductors. The solutions of the differential equation provide expressions for important hysteresis curves. From analysis based on the ideas of the Bean and Kim models, in which the critical current density is related to the width of the major loop, expressions for the major loop are used to establish a system of nonlinear equations for the critical current density, the equilibrium magnetization, and their derivatives. This system of equations can be used to evaluate free parameters in assumed forms for the critical current density. Here, the equations are used to compute values for {ital J}{sub {ital c}} and {ital M}{sub {ital e}} directly. Sample calculations with analytic forms of {ital f}, {ital g}, and {alpha}, and data from measured hysteresis curves are presented.

• OSTI ID: 5695258
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 69:4; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL CURRENT
CURRENTS
ELECTRIC CURRENTS
HYSTERESIS
MAGNETIC FLUX
MAGNETIZATION
MATHEMATICAL MODELS
NONLINEAR PROBLEMS
SUPERCONDUCTORS