An apparatus for the transport current versus magnetic field measurements in LN2 in the temperature range 77–124 K

Glowacki, B.A.; Robinson, E. A.; Ashworth, S.P.

doi:10.1016/s0011-2275(96)00111-7

Cited by 8 publications

(9 citation statements)

References 4 publications

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“…12), but only in zero field data. Fig 10 shows current-voltage curves measured in a pressurised liquid nitrogen vessel [56,57], in self field at different temperatures. The inset plot shows that the curves scale according to Eq.…”

Section: Experimental Current-voltage Datamentioning

confidence: 99%

Application of percolation theory to current transfer in granular superconductors

2002

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We investigate the description of current transfer in polycrystalline superconductors by percolation theory and its limitations. Various computer models that have been proposed are reviewed and related to the experimental and theoretical framework. While some conductor properties can be well described by percolation theory and models, we argue that a conceptual gap exists between experiment and theory. This gap has to be bridged by finding relations between electromagnetic and statistical parameters. We derive various such relations and compare them with recent simulation data. In particular, we suggest a new scaling law between the two fundamental variables 'current' and 'probability'.

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Section: Experimental Current-voltage Datamentioning

confidence: 99%

Application of percolation theory to current transfer in granular superconductors

2002

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“…The generally accepted criterion to determine the critical current of both low temperature (LTS) and high temperature (HTS) superconducting wires/tapes is E c = 1 µV cm −1 [1][2][3][4][5][6][7][8][9][10]. However, some authors prefer the more sensitive criterion of E c = 0.1 µV cm −1 or even some other value like e.g.…”

Section: Introductionmentioning

confidence: 99%

Differences between two definitions of the critical current of HTS coils

Pitel¹

2013

Supercond. Sci. Technol.

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Definition of the critical current of a coil made of anisotropic high temperature superconducting conductor is rather complicated and ambiguous, since the magnetic field generated across the winding can differ considerably in relation to both its magnitude and orientation. Two definitions of the critical current of such coils are discussed. The first definition, very often used in calculations to analyze the current carrying capacity, electric field and power dissipation of individual turns, represents an operating current at which an electric field of 1 µV cm −1 appears on one turn. The second definition represents an integral approach, and is used in experiments. This definition introduces the critical current of the coil as an operating current at which an average electric field E s , usually 0.1 µV cm −1 , appears on coil terminals. As an example, the distribution of the critical current and electric field of individual turns in the winding of a BSCCO model coil was analyzed. Critical currents of the coil as a function of an external magnetic field parallel with the coil axis were calculated according to both definitions. The results show that the first definition, which characterizes the winding at the local level, is suitable for HTS coils either operating in self-field or in a low external field, because the differences between the critical currents and n-indices of individual turns are considerable. The second criterion is suitable for the HTS coils operating in high fields, i.e. like high field insert coils. The self-field of a high field insert coil is negligible if the external field is high. As a result, the critical currents of all turns are almost identical, and the anisotropy in I c (B) characteristic plays practically no role. Rather unexpected behavior of the voltage-current characteristic of the model coil is predicted if an external field is applied.

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“…The critical current density J c was evaluated with a criterion of 1 µV cm −1 . In addition, dc transport measurements up to 900 A were made on non-irradiated wires at zero field [11]. The resistivity was measured with a current of 100 mA at various fixed fields while decreasing the temperature at a rate of 10 K h −1 .…”

Section: Methodsmentioning

confidence: 99%

Composite Cu/Fe/MgB₂superconducting wires and MgB₂/YSZ/Hastelloy coated conductors for ac and dc applications

Glowacki

Majoroš

Vickers

et al. 2003

Supercond. Sci. Technol.

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We discuss the results of a study of MgB2 multifilamentary conductors and coated conductors from the point of view of their future dc and ac applications. The correlation between the slope of the irreversibility line induced by neutron irradiation defects and in situ structural imperfections and the critical temperature and critical current density is discussed with respect to the conductor performance and applicability. We debate the possible origin of the observed anomalous decrease of ac susceptibility at 50 K in copper clad in situ powder-in-tube MgB2 wires. Different conductor preparation methods and conductor architectures, and attainable critical current densities are presented. Some numerical results on critical currents, thermal stability and ac losses of future MgB2 multifilamentary and coated conductors with magnetic cladding of their filaments are also discussed.

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An apparatus for the transport current versus magnetic field measurements in LN2 in the temperature range 77–124 K

Cited by 8 publications

References 4 publications

Application of percolation theory to current transfer in granular superconductors

Application of percolation theory to current transfer in granular superconductors

Differences between two definitions of the critical current of HTS coils

Composite Cu/Fe/MgB₂superconducting wires and MgB₂/YSZ/Hastelloy coated conductors for ac and dc applications

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An apparatus for the transport current versus magnetic field measurements in LN2 in the temperature range 77–124 K

Cited by 8 publications

References 4 publications

Application of percolation theory to current transfer in granular superconductors

Application of percolation theory to current transfer in granular superconductors

Differences between two definitions of the critical current of HTS coils

Composite Cu/Fe/MgB2superconducting wires and MgB2/YSZ/Hastelloy coated conductors for ac and dc applications

Contact Info

Product

Resources

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Composite Cu/Fe/MgB₂superconducting wires and MgB₂/YSZ/Hastelloy coated conductors for ac and dc applications