Open AccessMeasurement of Decay Time Constant of Shielding Current in ITER-TF Joint Samples
Author(s) -
S. Imagawa,
Hideki Kajitani,
T. Obana,
Suguru Takada,
S. Hamaguchi,
H. Chikaraishi,
Y. Onodera,
K. Takahata,
K. Matsui,
N. Koizumi
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1857/1/012013
Subject(s) - electromagnetic shielding , electromagnetic coil , joint (building) , magnetic field , electrical conductor , materials science , current (fluid) , field (mathematics) , nuclear magnetic resonance , electrical engineering , mechanics , physics , structural engineering , composite material , engineering , mathematics , quantum mechanics , pure mathematics
Joint sample tests have been carried out as a qualification test for ITER Toroidal Field (TF) coils. The joint sample comprises two short TF conductors that have “twin-box” joint terminals at both ends. The lower joint is a testing part that is a full size joint of the TF coils. Hall probes are attached on the lower joint box at around the center of the external field coil of the test facility. The magnetic field induced by shielding currents in the joint can be estimated from the difference between the measured magnetic field strength and the magnetic field generated by the external field coil. The magnetic field by the shielding currents during shut-off of the external field coil from -1.0 T is evaluated for six samples. The decay time constants of the shielding currents are gradually elongated with decrease of the shielding currents in all the samples. In comparison with simulation results, it is considered that the main shielding current flows in superconducting cables in the two conductors with crossing the jointed plane and that the joint resistance is decreased at low total current.