Reduction of AC losses in ultra-fine multifilamentary NbTi wires

Conference · Wed Mar 01 00:00:00 EST 1989 · IEEE Trans. Magn.; (United States)

OSTI ID:6043299

Cave, J R; Fevrier, A; Verhaege, T; Lacaze, A; Laumond, Y

The use of superconducting multifilamentary wires in 50/60 Hz AC applications is now possible due to advances in the new technology of ultra-fine filamentary wires (filaments 100 nm). While previous wires have shown very low losses, 1.5 10/sup -5/ W/(Am) and 5 10/sup -5/ W/(Am) at peak 50 Hz inductions of 0.5 T and 1 T respectively, (the unity W/(Am) = (losses in W/m/sup 3/)/(overall Jc in A/m/sup 2/) being a measure of the wire performance), the authors have shown that such wires are susceptible to proximity effects between neighboring filaments. In this article, they present AC loss measurements for a new series of wires where this proximity effect has been greatly reduced by increasing the distance between the filaments whilst retaining high values of the overall critical current density, typically 3000 A/mm/sup 2/ at 0.5 T. For the most performant wires 50 Hz AC losses in W/(Am) for small test coils are a factor of 10 lower for 0.5 T peak field and a factor of 3 lower at 1 T peak field. For wires with negligible proximity coupling there is a benefit from a reduction of losses at low fields as compared to that calculated by the Bean model, due to the small number of flux lines that thread across the width of each filament (increased entry field, surface currents, and reversible flux line motion).

• Research Organization: Laboratoires de Marcoussis, route de Nozay 91460 Marcoussis (FR); Alsthom, 3 avenue des Trois Chenes 90018 Belfort (FR)
• OSTI ID: 6043299
• Report Number(s): CONF-880812-
• Journal Information: IEEE Trans. Magn.; (United States), Vol. 25:2; Conference: Applied superconductivity conference, San Francisco, CA, USA, 21 Aug 1988
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
24 POWER TRANSMISSION AND DISTRIBUTION
SUPERCONDUCTING COILS
PERFORMANCE TESTING
SUPERCONDUCTING WIRES
DESIGN
CALCULATION METHODS
CURRENT DENSITY
NIOBIUM ALLOYS
POWER LOSSES
TECHNOLOGY ASSESSMENT
TITANIUM ALLOYS
ALLOYS
ENERGY LOSSES
LOSSES
TESTING
WIRES
420201* - Engineering- Cryogenic Equipment & Devices
200303 - Power Transmission & Distribution- Superconducting & Cryogenic Systems- (-1989)