title: Analytical and experimental investigation of electrical characteristics of a metallic insulation GdBCO coil.
abstract: This paper presents results, experimental and analytical, of the electrical characteristics of GdBCO single-pancake coils co-wound with a brass tape as metallic insulation (MI coil). The GdBCO pancakes were subjected to sudden discharge, charge-discharge, and over-current tests. The sudden discharge and charge-discharge test results of the MI coil demonstrated that MI coils can be charged and discharged significantly faster than non-insulated coils that are wound only with GdBCO tape. In over-current tests at 150 A (1.25I(c)), the MI coil exhibited better electrical behavior, i.e., self-protecting features, than its counterpart co-wound with Kapton tape, an insulator. Moreover, the experimental and analytical results are in agreement, validating the use of a concise equivalent parallel-RL circuit model for the MI coil to characterize its electrical behavior. Overall, the MI winding technique is highly promising to help build compact, mechanically robust, and self-protecting magnets composed of REBCO pancake coils. With no organic material in the winding, MI REBCO pancakes will be immune to neutron radiation damage, making the MI winding technique a viable option for fusion reactors, such as for toroidal field, poroidal field magnets, and central solenoid.
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul 136-713, South Korea.
authors.forename: D G
authors.initials: DG
authors.lastname: Yang
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul 136-713, South Korea.
authors.forename: Y H
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul 136-713, South Korea.
authors.forename: Y G
authors.initials: YG
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul 136-713, South Korea.
authors.forename: J B
authors.initials: JB
authors.lastname: Song
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong 5 ga, Seongbuk-gu, Seoul 136-713, South Korea.
authors.forename: H G
authors.initials: HG
authors.lastname: Lee