Accession Number : ADD015829

Title :   Method for Measuring the Resistive Transition and Critical Current in Superconductors using Pulsed Current.

Descriptive Note : Patent, Filed 31 Oct 90, patented 29 Jun 93,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : McGinnis, Wayne C ; Jones, Thomas E

Report Date : 29 Jun 1993

Pagination or Media Count : 10

Abstract : The present invention provides a method for measuring the intragranular and intergranular critical current of a granular superconductive material, comprising the steps of: (1) conducting a substantially rectangular electronic pulse through the material so as to conduct a current through the material such that when the intergranular critical current of the material is exceeded, any grains present in the material remain in a superconducting state when the current level is below the intragranular critical current; (2) measuring the current through the material while conducting the pulse; (3) measuring a voltage difference across the material while conducting the pulse; (4) determining the non-zero voltage difference across the material and contemporaneously measuring the current; and (5) determining the intragranular critical current through the material by varying the current to discern a current level at which the electrical resistance of the material increases to that of the non-superconducting state as the grains of the material transition from the superconducting to a non-superconducting state. This method may also be used to determine the critical current of a homogeneous superconductive material

Descriptors :   *PULSES, *TRANSITIONS, *PATENTS, *SUPERCONDUCTORS, *ELECTRIC CURRENT, *MEASUREMENT, *GRANULAR MATERIALS, ELECTRICAL RESISTANCE, ELECTRONICS, MATERIALS, VOLTAGE, HOMOGENEITY, COMPOSITE MATERIALS

Subject Categories : Electricity and Magnetism
      Laminates and Composite Materials
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE