High temperature superconducting current leads for fusion magnet systems

Conference · Tue Jan 01 00:00:00 EST 1991

OSTI ID:6129358

Wu, J L; Dederer, J T; Singh, S K ^[1]; Hull, J R ^[2]

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1. Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center
2. Argonne National Lab., IL (United States)

Superconducting magnets for fusion applications typically have very high operating currents. These currents are transmitted from the room temperature power supplies to the low temperature superconducting coils by way of helium-vapor-cooled current leads. Because of the high current magnitude and the resistive characteristics associated with the normal metallic lead conductors, a substantial amount of power is dissipated in the lead. To maintain a stable operation, a high rate of helium vapor flow, generated by the boil-off of liquid helium, is required to cool the lead conductors. This helium boil-off substantially increases both the installation capacity and the operating cost of the helium refrigerator/liquefier. The boil-off of liquid helium can be significantly reduced by employing ceramic high temperature superconductors, such as Y-Ba-Cu-O, in the low temperature part of the lead conductor structure. This concept utilizes the superconducting, as well as the low thermal conductivity properties of the superconductor materials in eliminating power dissipation in part of the current lead and in inhibiting heat conduction into the liquid helium pool, resulting in reduced helium boil-off. This design concept has been conclusively demonstrated by a 2-kA current lead test model using Y-Ba-Cu-O (123) material which, although not optimized in design, has significantly reduced the rate of helium boil-off in comparison to optimized conventional leads. There appear to be no major technological barriers for scaling up this design to higher current levels for applications in fusion magnet systems or in fusion related testing activities. The theoretical basis of the current lead concept, as well as the important design and technology issues are addressed. The potential cost saving derived from employing these leads in fusion magnets is also discussed. In addition, a design concept for a 10-kA lead is presented.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6129358
• Report Number(s): ANL/CP-74429; CONF-910968-21; ON: DE92001927
• Resource Relation: Conference: 14. IEEE symposium on fusion engineering, San Diego, CA (United States), 30 Sep - 3 Oct 1991
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Ma
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
SUPERCONDUCTING WIRES
HIGH-TC SUPERCONDUCTORS
THERMONUCLEAR REACTORS
COST
CRYOGENICS
DESIGN
HELIUM
POWER SUPPLIES
SUPERCONDUCTING MAGNETS
YTTRIUM COMPOUNDS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FLUIDS
GASES
MAGNETS
NONMETALS
RARE GASES
SUPERCONDUCTING DEVICES
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
WIRES
700480* - Fusion Technology- Component Development
Materials Studies- (1992-)
665411 - Basic Superconductivity Studies- (1992-)
360207 - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)