Presentation Monitoring and Control of the Magnet System of JT-60SA

福井, 良磨  ,  神谷, 宏治  ,  夏目, 恭平  ,  木津, 要  ,  河野, 勝己  ,  礒野, 高明  ,  村上, 陽之  ,  土屋, 勝彦  ,  Reinhard, Heller (Karlsruhe Institute of Technology)

The construction of the full-superconducting tokamak JT-60 Super Advanced (JT-60SA) isin progress under the JA-EU broader approach agreement. During cool down, nominal operation andwarm-up the thermal shields, the superconducting magnets and their structures, the high temperaturesuperconductor current leads (HTS CL) and the divertor cryo pumps have to be supplied with heliumat specific flow rates, pressures and temperatures. The monitoring of temperatures, mass flows, andpressures and the control of the helium flows is performed by a Magnet Controller (MC).A particular abnormal situation is a quench or a fast discharge of a magnet which wouldrequire many hours for recovery to normal operation. In order to avoid fast discharges as far as possible,the MC uses “safety interlocks” to supervise the magnet coils and the HTS CL. These interlocks reacton deviations of temperatures, pressures or mass flow rates from their nominal values and initiateappropriate counteractions. If a state reaches a critical threshold, a normal stop (NS) of a magnet isinitiated through the “Supervisory Control System and Data Acquisition System” (SCSDAS) byramping-down the current in the coils. In case of a fast discharge the MC acts directly on the powersupplies with parallel information to the SCSDAS.The thresholds are derived from simulations of the cryogenic loops using the thermalanalysis programs FLOWER, HEATER, and SUPERMAGNET.The presentation will describe the philosophy and logic of the Magnet Controller and explain thecalculation of some thresholds.
30th Symposium on Fusion Technology (SOFT 2018)

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