Pressure Drop Measurement of the JT-60SA Superconducting Magnets

The full-supercond ucting tokamak JT-60 Super Advanced (JT-60SA) has been constructed under the JA-EU Broader Approach agreement (Fukui
et al.
, 2019). The construction was completed in March 2020 followed by the first cool down operation. The magnet system used in JT-60SA consists of 18 toroidal field (TF) coils, 6 equilibrium field (EF) coils and 4 modules of central solenoid (CS) (Fukui
et al.
, 2020). All magnets are cooled by a forced flow of helium (Hoa
et al.
, 2012). During cool down uniform magnet temperatures are necessary. However, helium flow is difficult to be distributed accurately for each magnet, because the flow characteristics of each magnet are different. The objective of this work is to investigate the flow characteristics of all magnets in preparation for the next cool down operation.