Title :
Stability Test of a Superconducting W7-X Coil With Respect to Mechanical Disturbances
Author :
Hathiramani, Dag ; Bergmann, Thomas ; Bykov, Victor ; Chen, Peng ; Dänner, Wolfgang ; Dudek, Andrzej ; Fellinger, Joris ; Freundt, Stefan ; Genini, Laurent ; Höchel, Klaus ; Kallmeyer, Johannes Peter ; Lingertat, Johann ; Viebke, Holger ; Weber, Stephan ;
Author_Institution :
Max-Plack-Inst. fur Plasmaphysik, Greifswald, Germany
fDate :
6/1/2010 12:00:00 AM
Abstract :
The superconducting magnet system of the Wendelstein 7-X (W7-X) stellarator experiment consists of 50 non-planar and 20 planar coils which are supported by the central support structure and inter-coil structure elements. This highly loaded support system is prone to mechanical disturbances like stick-slip effects. On the other hand, the coils are built up from cable-in-conduit-conductors (CICC) whose strands are highly compressed by Lorentz forces during operation. Residual elastic energy release within a cable can be triggered by shock waves and corresponding frictional heat generation may occur. The released energy might come into the order of the conductor stability limit and possibly cause a quench. An experiment was performed to simulate the impact of such mechanical disturbances on W7-X coils with stability margins corresponding to different operation conditions. A non-planar coil installed within the magnet test facility was energized and then hit by a pendulum via a stainless steel transfer rod. The test has shown that mechanical disturbances expected in W7-X are not able to induce a quench in any of the foreseen W7-X operation scenarios.
Keywords :
impact (mechanical); impact testing; shock wave effects; superconducting coils; superconducting device reliability; superconducting device testing; Lorentz forces; Wendelstein stellarator experiment; cable-in-conduit-conductors; impact testing; mechanical disturbance; residual elastic energy; shock wave effect; stability testing; stick-slip effect; superconducting W7-X Coil; superconducting coils; superconducting device reliability; superconducting magnet system; Fusion reactors; stellarators; superconducting coils; superconducting device reliability;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2010.2040155