Journal ArticleDOI
Flux Jumps in Nonideal Type-2 Superconductors. I. Theory of Flux Jumps in Slabs
Reads0
Chats0
TLDR
In this article, a theory of flux jumps in a slab of a nonideal type-2 superconductor is developed by the use of a phenomenological theory of the flux motion.Abstract:
A theory of flux jumps in a slab of a nonideal type-2 superconductor is developed by the use of a phenomenological theory of flux motion To include explicitly in the theory the various quantities which are controllable experimentally, the temperature inside the slab is assumed to be approximately uniform Then a flux jump is characterized by a catastrophically sharp rise of the temperature of the sample The criteria for the occurrence of flux jumps are derived under such an assumption, together with the relation between the value of external magnetic field, at which a flux jump starts, and the sweeping rate of the external magnetic field Various behaviors of flux jumps observed experimentally are reasonably explained by the present theory in a quantitative wayread more
Citations
More filters
Journal ArticleDOI
A.C. loss and related effects in type II superconductors
TL;DR: In this article, the authors present a review of superconducting materials under a.c. conditions, and point out some features which are at present not too well understood, such as flux pinning and the method of flux motion.
Journal ArticleDOI
Effects of thermal insulation on flux jumps in Nb-50% Ti rods
TL;DR: In this paper, the temperatures of Nb-50% Ti rods are observed as the functions of an external magnetic field, when the rods are thermally insulated from liquid helium.
Journal ArticleDOI
Electromagnetic phenomena and hysteresis losses in superconductors
TL;DR: In this paper, various electromagnetic phenomena due to flux pinning effects are reviewed and explanations of these phenomena are given using the critical state model, including reversible fluxoid motion and the longitudinal field effect.
Journal ArticleDOI
System for coil simulation measurements of losses and instabilities in superconducting wires
TL;DR: In this paper, a new system for measuring ac losses in superconductors under coil simulation conditions is described, which is aimed to investigate instabilities in local points of a coil, and it is demonstrated by measuring the losses of a copper-clad single core Nb-Ti-Zr wire for several values of the ratio between the current and the magnetic field, which are inphase.
Journal ArticleDOI
AC loss and flux instabilities in single-component and double-component type II superconductors
TL;DR: In this paper, a two-component superconductor with Niobium and high-field superconductors is considered, and the authors show that when the flux density at the boundary between the two materials falls to zero, it is the stored energy in the flux distributions that gives more flux jumping with AC than with DC.
References
More filters
Journal ArticleDOI
Critical persistent currents in hard superconductors
TL;DR: In this paper, the authors investigated persistent currents induced in hard superconductors (HSC) by measuring the resulting magnetic effects and found that the Lorentz force plays a crucial role in determining the critical current density and the critical persistent currents in decay with a measurable rate.
Journal ArticleDOI
Theory of Flux Motion in Non-Ideal Type-II Superconductors
Fujio Irie,Kaoru Yamafuji +1 more
TL;DR: In this article, a phenomenological expression of the pinning force density is proposed, and the equation of force balance including this expression is shown to describe well the motion of magnetic fluxoids in non-ideal type-II superconductors in cooperation with the equation describing the continuity of magnetic flow.
Journal ArticleDOI
Magnetic instabilities in type-II superconductors
TL;DR: In this article, limited instability and flux jumping variation with magnetic field for flux pinning and Lorentz forces equilibrium in mixed state of type II SUPERCONDUCTOR was reported.
Journal ArticleDOI
Flux jumps in type II superconductors
TL;DR: In this article, the speed of flux jumps in pure and alloy specimens in the form of discs, which were placed perpendicularly in an applied magnetic field, was investigated in the light of earlier experimental results.