title: High resolution NMR measurements using a 400MHz NMR with an (RE)Ba2Cu3O7-x high-temperature superconducting inner coil: Towards a compact super-high-field NMR.
abstract: Use of high-temperature superconducting (HTS) inner coils in combination with conventional low-temperature superconducting (LTS) outer coils for an NMR magnet, i.e. a LTS/HTS NMR magnet, is a suitable option to realize a high-resolution NMR spectrometer with operating frequency >1GHz. From the standpoint of creating a compact magnet, (RE: Rare earth) Ba2Cu3O7-x (REBCO) HTS inner coils which can tolerate a strong hoop stress caused by a Lorentz force are preferred. However, in our previous work on a first-generation 400MHz LTS/REBCO NMR magnet, the NMR resolution and sensitivity were about ten times worse than that of a conventional LTS NMR magnet. The result was caused by a large field inhomogeneity in the REBCO coil itself and the shielding effect of a screening current induced in that coil. In the present paper, we describe the operation of a modified 400MHz LTS/REBCO NMR magnet with an advanced field compensation technology using a combination of novel ferromagnetic shimming and an appropriate procedure for NMR spectrum line shape optimization. We succeeded in obtaining a good NMR line shape and 2D NOESY spectrum for a lysozyme aqueous sample. We believe that this technology is indispensable for the realization of a compact super-high-field high-resolution NMR.
authors.affiliation: Center for Life Science Technologies, RIKEN, Yokohama 230-0045, Japan; Graduate School of Engineering, Chiba University, Chiba 236-8522, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Piao
authors.affiliation: Center for Life Science Technologies, RIKEN, Yokohama 230-0045, Japan; Faculty of Science and Technology, Sophia University, Yotsuya 102-8554, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Iguchi
authors.affiliation: Japan Superconductor Technology, Inc., Kobe, Hyogo 651-2271, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hamada
authors.affiliation: Superconducting Wire Unit, National Institute for Materials Science, Tsukuba 305-0003, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Matsumoto
authors.affiliation: JEOL RESONANCE Inc., Akishima, Tokyo 196-8558, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Suematsu
authors.affiliation: Graduate School of Engineering, Chiba University, Chiba 236-8522, Japan.
authors.forename: A T
authors.initials: AT
authors.lastname: Saito
authors.affiliation: Graduate School of Engineering, Chiba University, Chiba 236-8522, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: Graduate School of Engineering, Chiba University, Chiba 236-8522, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakagome
authors.affiliation: Faculty of Science and Technology, Sophia University, Yotsuya 102-8554, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takao
authors.affiliation: Center for Life Science Technologies, RIKEN, Yokohama 230-0045, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Center for Life Science Technologies, RIKEN, Yokohama 230-0045, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Maeda
authors.affiliation: Center for Life Science Technologies, RIKEN, Yokohama 230-0045, Japan; Graduate School of Engineering, Chiba University, Chiba 236-8522, Japan. Electronic address: yoshinori.yanagisawa@riken.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Yanagisawa
keywords: Compact super-high-field NMR; Ferromagnetic shim; High-resolution NMR measurement; NMR line shape optimization; NOESY; REBCO high-temperature superconducting (HTS) coil