Development and application of an epithermal neutron polarizing device

• Project/Area Number: 18K11929
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Oku Takayuki 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 J－PARCセンター, リーダー (10301748)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 中性子 / 偏極中性子 / 中性子散乱 / 中性子偏極子 / He-3スピンフィルター / SEOP / 熱外中性子 / スピン交換光ポンピング法 / 3Heスピンフィルター

Outline of Final Research Achievements

In this study, we have developed a neutron spin filter using He-3 gas based on the spin exchange optical pumping (SEOP) method for efficient polarization of epithermal neutrons.
Firstly, we developed a high-power (>100 W) and compact laser optics with a narrow laser wavelength of 0.2 nm, which is the absorption width of alkali metals used in the SEOP method. Then, we developed an aluminum silicate glass cell which encapsulated He-3 gas, rubidium, and potassium with an optimum mixing ratio to efficiently transfer the electron spin polarization of alkali metals to that of He-3. Then, we integrated both devices and developed an epithermal neutron spin filter.

Academic Significance and Societal Importance of the Research Achievements

J-PARCの大強度パルス中性子源が稼働し、それ以前はほとんど利用することができなかった熱外中性子等の高エネルギー中性子が得られるようになり、散乱実験やパルス中性子イメージングなど様々な実験で利用できるようになった。その一方で、偏極中性子に関して述べると、世界的に見ても中性子の偏極技術とその利用は、熱中性子（ エネルギー数十meV）以下のエネルギー領域に限定されている。熱外中性子を効率良く偏極して用いることができれば、新しい物理を切り開くブレークスルーとなるような基礎物理の研究や物性研究から産業利用まで、その波及効果は極めて大きい。そこで、本研究では、熱外中性子を偏極する技術開発を行った。

Research Products

• [Journal Article] Study of Neutron Nuclear Spin Correlation Term with a Polarized Xe Target (2021)
  • Author(s): Sakai Kenji、Oku Takayuki、Okudaira Takuya、Kai Tetsuya、Harada Masahide、Hiroi Kosuke、Hayashida Hirotoshi、Kakurai Kazuhisa、Shimizu Hirohiko M.、Hirota Katsuya、Yamamoto Tomoki、Ino Takashi
  • Journal Title: Proceedings of the 3rd J-PARC Symposium (J-PARC2019) Volume: 33
  • DOI: 10.7566/jpscp.33.011116
• [Journal Article] A Neutron Depolarization Measurement of Single Crystal Fe by Using a 3He Neutron Spin Filter and Magnetic Super-mirrors (2021)
  • Author(s): Okudaira Takuya、Oku Takayuki、Sakai Kenji、Hiroi Kosuke、Shinohara Takenao、Ino Takashi、Kira Hiroshi、Hayashida Hirotoshi、Suzuki Jun-ichi、Kakurai Kazuhisa、Aizawa Kazuya
  • Journal Title: Proceedings of the 3rd J-PARC Symposium (J-PARC2019) Volume: 33
  • DOI: 10.7566/jpscp.33.011096
• [Journal Article] Polarization analysis for small-angle neutron scattering with a 3He spin filter at a pulsed neutron source (2021)
  • Author(s): Okudaira Takuya、Ueda Yuki、Hiroi Kosuke、Motokawa Ryuhei、Inamura Yasuhiro、Takata Shin-ichi、Oku Takayuki、Suzuki Jun-ichi、Takahashi Shingo、Endo Hitoshi、Iwase Hiroki
  • Journal Title: Journal of Applied Crystallography Volume: 54 Issue: 2 Pages: 548-556
  • DOI: 10.1107/s1600576721001643
  • Peer Reviewed
• [Journal Article] Transverse asymmetry of γ rays from neutron-induced compound states of La140 (2020)
  • Author(s): Yamamoto T.、Okudaira T.、Endo S.、Fujioka H.、Hirota K.、Ino T.、Ishizaki K.、Kimura A.、Kitaguchi M.、Koga J.、Makise S.、Niinomi Y.、Oku T.、Sakai K.、Shima T.、Shimizu H. M.、Takada S.、Tani Y.、Yoshikawa H.、Yoshioka T.
  • Journal Title: Physical Review C Volume: 101 Issue: 6 Pages: 064624-064624
  • DOI: 10.1103/physrevc.101.064624
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Development and application of a 3He Neutron Spin Filter at J-PARC (2020)
  • Author(s): Okudaira T.、Oku T.、Ino T.、Hayashida H.、Kira H.、Sakai K.、Hiroi K.、Takahashi S.、Aizawa K.、Endo H.、Endo S.、Hino M.、Hirota K.、Honda T.、Ikeda K.、Kakurai K.、Kambara W.、Kitaguchi M.、Oda T.、Ohshita H.、Otomo T.、Shimizu H.M.、Shinohara T.、Suzuki J.、Yamamoto T.
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 977 Pages: 164301-164301
  • DOI: 10.1016/j.nima.2020.164301
  • NAID: 120006882449
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Development of an in Situ 3He NSF Using SEOP Technique with an Evaluation System for the Pulsed Neutron Source (2020)
  • Author(s): Okudaira T.、Oku T.、Sakai K.、Ino T.、Hayashida H.、Hiroi K.、Shinohara T.、Kakurai K.、Aizawa K.
  • Journal Title: Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques Volume: 14 Issue: S1 Pages: S165-S168
  • DOI: 10.1134/s1027451020070356
  • Peer Reviewed
• [Journal Article] 偏極中性子 (2018)
  • Author(s): 平賀 晴弘、山口 泰男、丸山 龍治、奥 隆之、猪野 隆
  • Journal Title: 波紋 Volume: 28 Pages: 144-149
  • NAID: 130007746204
  • Open Access
• [Journal Article] Development of a Neutron Spin Filter for a T Violation Search in Compound Nuclei (2018)
  • Author(s): T. Yamamoto, H. M. Shimizu, M. Kitaguchi, K. Hirota, T. Okudaira, C. C. Haddock, N. Oi, I. Ito, S. Endo, S. Takada, J. Koga, T. Yoshioka, T. Ino, K. Asahi, T. Momose, T. Iwata, K. Sakai, T. Oku, A. Kimura, M. Hino, T. Shima, and Y. Yamagata
  • Journal Title: JPS Conference Proceeding Volume: 22
  • Peer Reviewed / Open Access
• [Presentation] 中性子デバイス (2021)
  • Author(s): 奥 隆之
  • Organizer: MLFシンポジウム
• [Presentation] Development and application of a spin-exchange optical pumping He-3 neutron spin filter at J-PARC (2020)
  • Author(s): Takayuki Oku
  • Organizer: ESS Polarisation Workshop
  • Int'l Joint Research / Invited
• [Presentation] Development and application of a SEOP-based 3He spin filter at J-PARC (2020)
  • Author(s): Takayuki Oku
  • Organizer: 2020 Neutron Polarization Workshop
  • Int'l Joint Research / Invited
• [Presentation] Development and application of a spin-exchange optical pumping 3He neutron spin filter at J-PARC (2019)
  • Author(s): Takayuki Oku
  • Organizer: 中性子散乱アジア・オセアニア会議
  • Int'l Joint Research / Invited
• [Presentation] A neutron depolarization measurement of a single crystal Fe by using a 3He neutron spin filter and magnetic super-mirrors (2019)
  • Author(s): Takayuki Oku
  • Organizer: 3rd J-PARC Symposium
  • Int'l Joint Research
• [Presentation] 単結晶鉄試料の透過中性子偏極度解析実験 (2018)
  • Author(s): 奥隆之
  • Organizer: 日本中性子科学会
• [Presentation] A neutron depolarization measurement of a single crystal Fe by using a 3He neutron spin filter and magnetic super-mirrors (2018)
  • Author(s): T. Oku
  • Organizer: Polarized Neutrons for Condensed Matter Investigations (PNCMI)
  • Int'l Joint Research