title: Persistent-current switch for pancake coils of rare earth-barium-copper-oxide high-temperature superconductor: Design and test results of a double-pancake coil operated in liquid nitrogen (77-65 K) and in solid nitrogen (60-57 K).
abstract: We present design and test results of a superconducting persistent current switch (PCS) for pancake coils of rare-earth-barium-copper-oxide, REBCO, high-temperature superconductor (HTS). Here, a REBCO double-pancake (DP) coil, 152-mm ID, 168-mm OD, 12-mm high, was wound with a no-insulation technique. We converted a ∼10-cm long section in the outermost layer of each pancake to a PCS. The DP coil was operated in liquid nitrogen (77-65 K) and in solid nitrogen (60-57 K). Over the operating temperature ranges of this experiment, the normal-state PCS enabled the DP coil to be energized; thereupon, the PCS resumed the superconducting state and the DP coil field decayed with a time constant of 100 h, which would have been nearly infinite, i.e., persistent-mode operation, were the joint across the coil terminals superconducting.
authors.affiliation: Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology , 170 Albany Street, Cambridge, Massachusetts 02139, USA.
authors.forename: Timing
authors.initials: T
authors.lastname: Qu
authors.affiliation: Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology , 170 Albany Street, Cambridge, Massachusetts 02139, USA.
authors.forename: Philip C
authors.identifier: 0000-0003-4906-6169
authors.initials: PC
authors.lastname: Michael
authors.affiliation: Wentworth Institute of Technology , 550 Huntington Ave, Boston, Massachusetts 02115, USA.
authors.forename: John
authors.initials: J
authors.lastname: Voccio
authors.affiliation: Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology , 170 Albany Street, Cambridge, Massachusetts 02139, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Bascuñán
authors.affiliation: National High Magnetic Field Laboratory, Florida State University , Tallahassee, 2031 Paul Dirac Drive, Florida 32310, USA.
authors.forename: Seungyong
authors.initials: S
authors.lastname: Hahn
authors.affiliation: Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology , 170 Albany Street, Cambridge, Massachusetts 02139, USA.
authors.forename: Yukikazu
authors.initials: Y
authors.lastname: Iwasa