Fusion Science and Technology / Volume 56 / Number 2 / August 2009 / Pages 685-689
ITER / Eighteenth Topical Meeting on the Technology of Fusion Energy (Part 2)
The Toroidal Field (TF) system of ITER consists of 18 coils with design nominal current of 68 kA operating in steady state mode that provides 5.4 T in the plasma centre. The winding pack (WP) of each coil is formed by 7 stacked double pancakes which are connected between them in the coil lower region, sharing space with the current leads, supercritical Helium cooling piping and manifolds. The TF coils of ITER are not nuclear safety related, but the release of the 41 GJ of magnetic energy in a controlled way in case of a quench and the difficulties of replacing a failing TF coil make a reliable coil instrumentation design essential as investment protection.
The present paper describes not only the principles of the primary and secondary quench detection system of the ITER TF coils but also the operation monitoring instrumentation. The reliability of strain gauges, temperature sensors, pressure gauges and flow meters in the cryogenic environment and high electromagnetic noise environment is also discussed.