skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance

Abstract

Achieving a higher magnetic field is important for solid-state nuclear magnetic resonance (NMR). But a conventional low temperature superconducting (LTS) magnet cannot exceed 1 GHz (23.5 T) due to the critical magnetic field. Thus, we started a project to replace the Nb{sub 3}Sn innermost coil of an existing 920 MHz NMR (21.6 T) with a Bi-2223 high temperature superconducting (HTS) innermost coil. Unfortunately, the HTS magnet cannot be operated in persistent current mode; an external dc power supply is required to operate the NMR magnet, causing magnetic field fluctuations. These fluctuations can be stabilized by a field-frequency lock system based on an external NMR detection coil. We demonstrate here such a field-frequency lock system in a 500 MHz LTS NMR magnet operated in an external current mode. The system uses a {sup 7}Li sample in a microcoil as external NMR detection system. The required field compensation is calculated from the frequency of the FID as measured with a frequency counter. The system detects the FID signal, determining the FID frequency, and calculates the required compensation coil current to stabilize the sample magnetic field. The magnetic field was stabilized at 0.05 ppm/3 h for magnetic field fluctuations of around 10 ppm.more » This method is especially effective for a magnet with large magnetic field fluctuations. The magnetic field of the compensation coil is relatively inhomogeneous in these cases and the inhomogeneity of the compensation coil can be taken into account.« less

Authors:
;  [1]; ;  [2]; ;  [3]; ;  [4]; ;  [5];  [6];  [7];  [1]
  1. RIKEN Systems and Structural Biology Center, Yokohama, Kanagawa 230-0045 (Japan)
  2. Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045 (Japan)
  3. Graduate School of Chiba University, Chiba, Chiba 263-8522 (Japan)
  4. JEOL RESONANCE Inc., Akishima, Tokyo 196-8558 (Japan)
  5. Kobe Steel, Ltd., Kobe, Hyogo 651-2271 (Japan)
  6. Probe Laboratory Inc., Hamura, Tokyo 205-0021 (Japan)
  7. Superconducting Wire Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0003 (Japan)
Publication Date:
OSTI Identifier:
22093793
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 83; Journal Issue: 10; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; AVAILABILITY; DETECTION; FREQUENCY MEASUREMENT; HIGH-TC SUPERCONDUCTORS; LITHIUM 7; MAGNETIC FIELDS; NUCLEAR MAGNETIC RESONANCE; SENSORS; SOLIDS; SUPERCONDUCTING COILS; SUPERCONDUCTING MAGNETS

Citation Formats

Takahashi, Masato, Maeda, Hideaki, Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045, Ebisawa, Yusuke, Tennmei, Konosuke, Yanagisawa, Yoshinori, Nakagome, Hideki, Hosono, Masami, Takasugi, Kenji, Hase, Takashi, Miyazaki, Takayoshi, Fujito, Teruaki, Kiyoshi, Tsukasa, and Yamazaki, Toshio. Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance. United States: N. p., 2012. Web. doi:10.1063/1.4757576.
Takahashi, Masato, Maeda, Hideaki, Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045, Ebisawa, Yusuke, Tennmei, Konosuke, Yanagisawa, Yoshinori, Nakagome, Hideki, Hosono, Masami, Takasugi, Kenji, Hase, Takashi, Miyazaki, Takayoshi, Fujito, Teruaki, Kiyoshi, Tsukasa, & Yamazaki, Toshio. Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance. United States. https://doi.org/10.1063/1.4757576
Takahashi, Masato, Maeda, Hideaki, Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045, Ebisawa, Yusuke, Tennmei, Konosuke, Yanagisawa, Yoshinori, Nakagome, Hideki, Hosono, Masami, Takasugi, Kenji, Hase, Takashi, Miyazaki, Takayoshi, Fujito, Teruaki, Kiyoshi, Tsukasa, and Yamazaki, Toshio. 2012. "Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance". United States. https://doi.org/10.1063/1.4757576.
@article{osti_22093793,
title = {Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance},
author = {Takahashi, Masato and Maeda, Hideaki and Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045 and Ebisawa, Yusuke and Tennmei, Konosuke and Yanagisawa, Yoshinori and Nakagome, Hideki and Hosono, Masami and Takasugi, Kenji and Hase, Takashi and Miyazaki, Takayoshi and Fujito, Teruaki and Kiyoshi, Tsukasa and Yamazaki, Toshio},
abstractNote = {Achieving a higher magnetic field is important for solid-state nuclear magnetic resonance (NMR). But a conventional low temperature superconducting (LTS) magnet cannot exceed 1 GHz (23.5 T) due to the critical magnetic field. Thus, we started a project to replace the Nb{sub 3}Sn innermost coil of an existing 920 MHz NMR (21.6 T) with a Bi-2223 high temperature superconducting (HTS) innermost coil. Unfortunately, the HTS magnet cannot be operated in persistent current mode; an external dc power supply is required to operate the NMR magnet, causing magnetic field fluctuations. These fluctuations can be stabilized by a field-frequency lock system based on an external NMR detection coil. We demonstrate here such a field-frequency lock system in a 500 MHz LTS NMR magnet operated in an external current mode. The system uses a {sup 7}Li sample in a microcoil as external NMR detection system. The required field compensation is calculated from the frequency of the FID as measured with a frequency counter. The system detects the FID signal, determining the FID frequency, and calculates the required compensation coil current to stabilize the sample magnetic field. The magnetic field was stabilized at 0.05 ppm/3 h for magnetic field fluctuations of around 10 ppm. This method is especially effective for a magnet with large magnetic field fluctuations. The magnetic field of the compensation coil is relatively inhomogeneous in these cases and the inhomogeneity of the compensation coil can be taken into account.},
doi = {10.1063/1.4757576},
url = {https://www.osti.gov/biblio/22093793}, journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 10,
volume = 83,
place = {United States},
year = {Mon Oct 15 00:00:00 EDT 2012},
month = {Mon Oct 15 00:00:00 EDT 2012}
}