Magnetic instabilities in superconducting composites

Abstract

Abstract. The stability of electric currents in multifilamentary superconducting composites against flux jumps is discussed in detail. The normal procedure for such a quantitative stability investigation is carried out. In some particular cases the stability criteria are found and analysed.

Critical state stability in type-II superconductors and superconducting-normal-metal composites

“…In a number of cases, such materials can be regarded as an effective homogeneous anisotropic medium (Hart, 1969;Carr, 1974Carr, , 1975aCarr, , 1975bDuchateau and Turk, 1975a, l975b;Kremlev et al , 1976aKremlev et al , , 1977. The parameters ot' such a medium are found by averaging their local values over a region containing a rather high number of elements of the composite structure.…”

“…12 is the dependence of P, upon~at different ge, found with the aid of numerical solution of this equation (curves A"B,) (Kremlev et al , 1977). For y»1 the solution to the problem can be obtained analytically (Kremlev et al , 1977;Maksimov and Mints, 1979).…”

“…Therefore, in the main approximation with respect to~» 1, the stability depends only upon the full size of the regions where j0 and, consequently, heat release takes place upon the emergence of perturbation (Kremlev et a/. , 1976a(Kremlev et a/. , , 1977.…”

“…Let us now write conditions (2) and (3) in algebraic form, for example, in application to multif ilament composites (Kremlev et al , 1976a(Kremlev et al , , 1977. The smallest scale on which, for y» 1, the solutions to Eqs.…”

Dynamic stability of edge-cooled superconducting tapes

“…9 Our mathematical analysis is similar to the two dimensional studies of Kremlev et al 8 The main difference is that in our studies the superconductor and stabilizer must be treated as separate regions. Specifically, Kremlev et al use a cross section averaged relation between E and J, which ultimately leads to a single region description of the "averaged" material.…”