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Monitoring the build-up of hydrogen polarization for polarized hydrogen–deuteride (HD) targets with nuclear magnetic resonance (NMR) at 17 T
https://repo.qst.go.jp/records/84731
https://repo.qst.go.jp/records/84731bae8e8be-31a0-4fb7-86d5-7a272c970cd4
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2021-10-01 | |||||
| タイトル | ||||||
| タイトル | Monitoring the build-up of hydrogen polarization for polarized hydrogen–deuteride (HD) targets with nuclear magnetic resonance (NMR) at 17 T | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Ohta, T.
× Ohta, T.× Mamoru, Fujiwara× T. Hotta× Ide, I.× Ishizaki, K.× Kohri, H.× Yanai, Y.× Yosoi, M.× Mamoru, Fujiwara |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | We report on the frozen-spin polarized hydrogen–deuteride (HD) targets for photoproduction experiments at SPring-8/LEPS. Pure HD gas with a small amount of ortho-H2 (∼0.1%) and a very small amount of para-D2 (∼0.001%) was liquefied and solidified by liquid helium. The temperature of the produced solid HD was reduced to about 30 mK with a dilution refrigerator. A magnetic field (17 T) was applied to the HD to grow the polarization with the static method. After the aging of the HD at low temperatures in the presence of a high-magnetic field strength for three months, the polarization froze. Almost all ortho-H2 molecules were converted to para-H2 molecules. Most remaining para-D2 molecules were converted to ortho-D2 molecules. The para-H2 and ortho-D2 molecules exhibited weak spin interactions with the HD. If the concentrations of the ortho-H2 and para-D2 were reduced appropriately at the beginning of the aging process, the aging time can be shortened. We have developed a new nuclear magnetic resonance (NMR) system to measure the relaxation times (T1) of the 1H and 2H nuclei with two frequency sweeps at the respective frequencies of 726 MHz and 111 MHz and succeeded in the monitoring of the polarization build-up at decreasing temperatures from 600 mK to 30 mK at 17 T. Automatic NMR measurements with the frequency sweeps enabled us to omit the use of a manual tuning circuit and to remove magnetic field sweeps with eddy current heat. This technique enables us to optimize the concentration of the ortho-H2 and to efficiently polarize the HD target within a shortened aging time. | |||||
| 書誌情報 |
Review of Scientific Instruments 巻 91, 号 9, p. 095104, 発行日 2021-09 |
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| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0034-6748 | |||||
| DOI | ||||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | 10.1063/5.0005696 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://aip.scitation.org/doi/10.1063/5.0005696 | |||||
