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Title: Energy dissipation of composite multifilamentary superconductors for high-current ramp-field magnet applications

Thesis/Dissertation ·
OSTI ID:10180276

Energy dissipation, which is also called AC loss, of a composite multifilamentary superconducting wire is one of the most fundamental concerns in building a stable superconducting magnet. Characterization and reduction of AC losses are especially important in designing a superconducting magnet for generating transient magnetic fields. The goal of this thesis is to improve the understanding of AC-loss properties of superconducting wires developed for high-current ramp-field magnet applications. The major tasks include: (1) building an advanced AC-loss measurement system, (2) measuring AC losses of superconducting wires under simulated pulse magnet operations, (3) developing an analytical model for explaining the new AC-loss properties found in the experiment, and (4) developing a computational methodology for comparing AC losses of a superconducting wire with those of a cable for a superconducting pulse magnet. A new experimental system using an isothermal calorimetric method was designed and constructed to measure the absolute AC losses in a composite superconductor. This unique experimental setup is capable of measuring AC losses of a brittle Nb{sub 3}Sn wire carrying high AC current in-phase with a large-amplitude pulse magnetic field. Improvements of the accuracy and the efficiency of this method are discussed. Three different types of composite wire have been measured: a Nb{sub 3}Sn modified jelly-roll (MJR) internal-tin wire used in a prototype ohmic heating coil, a Nb{sub 3}Sn internal-tin wire developed for a fusion reactor ohmic heating coil, and a NbTi wire developed for the magnets in a particle accelerator. The cross sectional constructions of these wires represent typical commercial wires manufactured for pulse magnet applications.

Research Organization:
Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG02-91ER54110
OSTI ID:
10180276
Report Number(s):
DOE/ER/54110-3; PFC/RR-94-8; ON: DE94018416; BR: 35AT15010/35AT15030; TRN: 94:016778
Resource Relation:
Other Information: TH: Thesis (Ph.D.); PBD: Jan 1993
Country of Publication:
United States
Language:
English