Superconducting permanent magnets. Final report, June 1987-August 1988

Technical Report · Thu Mar 01 04:00:00 EST 1990

OSTI ID:7120772

Wipf, S L; Laquer, H L

The concept of superconducting permanent magnets or Super-Permanent magnets, with fields trapped in shells or cylinders of type II superconductors is an old one. Unfortunately, the low values of 0.5 to 1T for the first flux jump field, which is independent of the actual current density, have frustrated its implementation with the classical Type II superconductors. The fact that the flux jump fields for high temperature superconductors should be almost an order of magnitude larger at liquid nitrogen temperatures, allows us to reconsider these options. Analysis of the hysteresis patterns, based on the critical state model, shows that, if the dimensions are chosen so that the value of the first flux jump field Bfj at the given operating temperature, a temporarily applied field of 2Bfj will trap 0.5 Bfj. Thus for a Bfj of 6T, a permanent field of 3T should be trapped with an energy product of 1.8MJ/cu m (225 MGOe). This is five times as large as for the best permanent magnet materials. We discuss means to verify the analysis and the limitations imposed by the low critical current densities in presently available high temperature superconductors.

• Research Organization: Cryopower Associates, Los Alamos, NM (USA)
• OSTI ID: 7120772
• Report Number(s): AD-A-218944/7/XAB; CPI-TR--88-01B
• Country of Publication: United States
• Language: English

Related Subjects

426001* -- Engineering-- Superconducting Devices & Circuits-- (1990-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL CURRENT
CURRENT DENSITY
CURRENTS
DOCUMENT TYPES
ELECTRIC CURRENTS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
EQUIPMENT
HIGH-TC SUPERCONDUCTORS
HYSTERESIS
MAGNETS
PERFORMANCE
PERMANENT MAGNETS
PROGRESS REPORT
SUPERCONDUCTING DEVICES
SUPERCONDUCTING MAGNETS
SUPERCONDUCTORS
TECHNOLOGY ASSESSMENT
TYPE-II SUPERCONDUCTORS