Pulsed Field Losses and Coupling Current Loop in a Large Current Superconductor

Abstract

Pulsed field losses in a short sample (445 mm length) of 46‐kA Nb3Sn cable‐in‐conduit conductor of superconducting magnet for the fusion experimental reactor “ITER” are measured by a calorimetric method. The coupling time constant between strands is obtained as 30 ms through pulsed loss. Based on this time constant and interstrand conductance measurement, it is expected that there is a coupling current loop length of about 400 mm, which is longer than half the fabrication twist pitch in the fourth cabling stage. A geometrical calculation on several‐stage cabling shows this value to be reasonable. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 142(4): 27–33, 2003; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/eej.10088

Magnetic field measurements of JT-60SA CS model coil

“…The first instance is an SMES model coil for a small-scale 100 kWh SMES device, which was launched by the Ministry of International Trade and Industry of Japan [7,10,11]. The second and third are the CS insert and Nb 3 Al insert coils, respectively [12][13][14][15][16]. These coils were fabricated and tested by the Japan Atomic Energy Research Institute.…”

“…The fifth is the inner shaping (IS) coil for the LHD poloidal coil [19,20]. Specifications of these coils are listed in Table 4 [7,[10][11][12][13][14][15][16][17][18][19][20].…”

Simulation of Quench Tests of the Central Solenoid Insert Coil in the ITER Central Solenoid Model Coil

“…This value is about 4 times higher than the diameter of the original Nb filaments. Two components of the coupling losses with long and short time constants were observed [13]- [15]. The short time constant corresponds to the time constant measured in the short sample with one twist pitch length [13].…”

“…Two components of the coupling losses with long and short time constants were observed [13]- [15]. The short time constant corresponds to the time constant measured in the short sample with one twist pitch length [13]. The coupling loss increases due to the electromagnetic force during the pulse operation [16].…”