Abstract
This paper presents early results of the R&D programme carried out to optimize NbTi wires for the ITER poloidal field coils (PF). Using TEM, the influence of treatment conditions on the microstructure was investigated. The purpose is to find relations between the alloy microstructure and the NbTi wire critical current densities at 4.2 K. Typical NbTi with high critical current density at 4.2 K shows a microstructure (in transverse cross-section) with strongly folded and curled of α-Ti pinning centers dispersed within the superconducting β-NbTi matrix. It is believed that the higher temperature is beneficial to a higher 4.2 K Jc values, but these Jc values slightly decrease with increasing heat treatment durations.
Original language | English |
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Pages (from-to) | 1840-1842 |
Number of pages | 3 |
Journal | Physica C: Superconductivity and its Applications |
Volume | 468 |
Issue number | 15-20 |
DOIs | |
State | Published - 15 Sep 2008 |
Keywords
- Critical current density
- ITER
- Microstructure
- NbTi superconducting wire