KSTAR Magnetic Field Measurement During the Commissioning and Remanent Field Evaluation

• Published in: IEEE transactions on applied superconductivity Vol. 19; no. 3; pp. 1573 - 1576
• Main Authors: Yonekawa, H., Kim, Y.O., Hyun Jung Lee, Yoon, S.W., Hahn, S.H., Lee, K.S., Lee, D.K., Soo Hwan Park, Yong Chu, Bang, E.N., Park, K.R., Oh, Y.K., Bak, J.S., Leuer, J.A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-06-2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Assembly; Conducting materials; Electric connection. Cables. Wiring; Electrical engineering. Electrical power engineering; Electromagnets; Exact sciences and technology; Incoloy 908; Magnetic field measurement; Magnetic fields; Magnetic materials; Magnetic sensors; Magnetism; Plasma measurements; remanent magnetic field; Saturation magnetization; Superconducting cables; Superconducting coils; superconducting magnet coil; Superconducting magnets; Various equipment and components; {\rm Nb}_{3}{\rm Sn}; Asia; Korea; Tokamak; Plasma; Hall effect device; Incoloy 908; In situ; In situ test; superconducting magnet coil; Ferromagnetic materials; Superconducting coils; Magnetic measurement; Commissioning; Hysteresis loop; Superconducting magnet; Pipe cable; Magnetic field measurement; Nb; Remanent magnetization; remanent magnetic field; Magnet coils; Electrical conductor; Sn; Magnetic field; Machine windings
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2009.2018486

An in situ measurement of the magnetic field generated by the assembled superconducting magnet coils was held by using precision Hall sensors during the commissioning of the Korea Superconducting Tokamak Advanced Research (KSTAR) device. This was done in order to investigate the magnetic influence of Incoloy 908, which is the jacket material for the cable-in-conduit conductors (CICCs) of the Nb 3 Sn coils. After the PF coils were discharged from 1 kA the vertical remanent field at the plasma center was more than 10 G, while the TF coils were not energized. The vertical magnetic field generated by the PF coils had a discrepancy of up to 50 G between measurement and the calculation assuming no magnetic influence of Incoloy 908. Thus, non-negligible ferromagnetism was identified and attributed to Incoloy 908. In contrast, most of the hysteresis observed in the magnetic measurements was eliminated when the Incoloy 908 of the TF windings was saturated by the TF coil charging.