Results of the first JT-60 SA toroidal field coils tests in the cold test facility

•The 5 first JT-60SA TF coils have been successfully tested at 5K and 25.7kA.•One major insulation problem was detected, analyzed and repaired.•Cooling down problems like clogging and temperature gradient were solved.•The inter pancakes joint resistances are below the 2nΩ specified value.•The quench temperature of each coil is above the 7.3K specified value. JT-60SA is a fusion experiment which is jointly constructed by Japan and Europe and which shall contribute to the early realization of fusion energy, by providing support to the operation of ITER, and by addressing key physics issues for ITER and DEMO. In order to achieve these goals, the existing JT-60U experiment will be upgraded to JT-60SA by using superconducting coils. The 18 TF coils of the JT-60SA device are provided by European industry and tested in a Cold Test Facility (CTF) at CEA Saclay. The first coils were tested at the nominal current of 25.7kA and at a temperature between 5K and 7.5K. The main objective of these tests is to check the TF coils performances and hence mitigate the fabrication risks. These first tests allowed checking a certain number of performances of the first TF coils: DC/AC insulation, cooling down characterization, RRR of the conductor, pressure drop in the winding pack and temperature margin against a quench. This paper will give an overview of the main experimental results obtained during these tests. These results will be analyzed and discussed in the light of the expected TF coils performances.