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Test and Development of New Production Method for Ultracold Neutrons

Research Project

Project/Area Number 10554006
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section展開研究
Research Field 素粒子・核・宇宙線
Research InstitutionTokyo Institute of Technology

Principal Investigator

ASAHI Koichiro  Graduate School of Science and Engineering, Tokyo Institute of Technology, Professor, 大学院・理工学研究科, 教授 (80114354)

Co-Investigator(Kenkyū-buntansha) SAKAI Kenji  Graduate School of Science and Engineering, Tokyo Institute of Technology, Associate, 大学院・理工学研究科, 助手 (40272661)
Project Period (FY) 1998 – 1999
Project Status Completed (Fiscal Year 1999)
Budget Amount *help
¥12,900,000 (Direct Cost: ¥12,900,000)
Fiscal Year 1999: ¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1998: ¥5,700,000 (Direct Cost: ¥5,700,000)
Keywordsuntracold neutrons / electric dipole moment / weak interaction / magnetic moment / adiabatic fast passage method / magnetic deceleration / pulsed neutron source / alternating magnetic field
Research Abstract

Neutrons provide an important experimental opportunities in fundamental physics researches through, e.g., searches for an electric dipole moment, studies of beta decays, and observations of quantum interference phenomena. In such studies, the availability of neutrons at energies below EィイD2crィエD2 0.25 【similar or equal】μeV (ultracold neutrons, or UCN) is essential, because the spatial confinement of neutrons in a bottle for experiment is only possible for such low energies. In the present work we proposed a new method for the production of UCN, investigated its performances through computer simulations, and developed techniques for the testing and realization of its concepts.
The method comprises the deceleration of neutrons through the interaction of a neutron magnetic moment and an external magnetic field. The deceleration effect is accumulated by repeating the spin flip at high- and low-field positions during the flight by means of the adiabatic passage nuclear magnetic resonance tec … More hnique. The deceleration effect is varied according to the time of flight of neutrons from a pulsed neutron source, so that the final kinetic energies converge into narrow region below EィイD2crィエD2.
Computer simulations were performed for a designed setup consisting of 160 sections of superconducting magnets which implement a field alternating from 0.59 T to 4.95 T along the neutron flight path. The result shows that an about 70 times higher UCN density compared to the best density presently available in the world will be realized.
Then a prototype section with a normal-conducting magnet and an rf coil for the spin flip was constructed. Solid state neutron detectors with a ィイD17ィエD1Li converter foil in front were developed for the UCN detection. Using low-energy neutron beams from the super-mirror turbine facility at Kyoto University Research Reactor Institute, an experimental study is in progress to test validity of the proposed deceleration method and to develop techniques required for it. In the runs performed up to now we have suceeded in obtaining neutrons monochromafized in a velocity range v = 4.27-5.48 m/s with a counting rate of 0.52 mcps. This result suggests that the detection of the deceleration effect will be realized with a planned setup change in the upstream neutron duct. Less

Report

(3 results)
  • 1999 Annual Research Report   Final Research Report Summary
  • 1998 Annual Research Report
  • Research Products

    (20 results)

All Other

All Publications (20 results)

  • [Publications] 旭耕一郎: "核スピンで探る基礎物理"冷中性子干渉実験の進展とその応用(II)ワークショップ報告書. KURRI-TR-426. 88-95 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] 酒井健二、内山靖人、旭耕一郎、他: "スピンフリップ磁気減速とUCNの生成"「冷中性子干渉実験の進展とその応用(III)」研究会報告書. KURRI-KR-35. 81-87 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] 内山靖人、旭耕一郎、酒井健二、他: "多段スピンフリップ磁気減速法による超冷中性子生成法の開発"Proc.of the 4th Workshop on Nuclear Physics and Fundamental Physics with Neutrons IV. KEK Proc 99-4. 187-209 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] H. Ogawa, K. Asahi, K. Sakai et al.: "Magnetic Moment and Electric Quadrupole Moment of the ^<18>N Ground State"Phys. Lett. B. 451. 11-18 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Asahi, H. Yoshimi, K. Sakai et al.: "Fundamental Physics with Polarized Nuclear Spins - New type of Spin Maser for the Neutron EDM Measurements"Czechoslovak Journal of Physics. 50(出版予定). (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] H. Ogawa, K. Asahi, K. Sakai et al.: "Nuclear Moments Measurements with Polarized Radioactive Beams"Proceedings of the Fourth International Workshop on Laser Spectroscopy on Beams of Radioactive Nuclei, Poznan, Poland, May 1999. (出版予定). (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Asahi: "Nuclear and fundamental physics with spin-polarized nuclei"Genshikaku Kenkyu. 44, No4. 45-63 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Asahi: "Fundamental physics with spind"KURRI Technical Report. 426. 88-95 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Sakai, Y. Uchiyama, K. Asahi, et al.: "Spin-flip magnetic deceleration and the production of untracold neutrons"KUR Report. KR35. 81-87 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] Y. Uchiyama, K. Asahi, K. Sakai et al.: "UCN production by spin-flip magnetic deceleration method"KEK Proceedings. 99-4. 187-209 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] H. Ogawa, K. Asahi, K. Sakai et al.: "Magnetic Moment and Electric Quadrupole Moment of the ィイD118ィエD1N Ground State"Phys. Lett. B. 451. 11-18 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Asahi, H. Yoshimi, K. Sakai et al.: "Fundamental Physics with Polarized Nuclear Spins - New Type of Spin Maser for the Neutron EDM Measurements"Czechoslovak Journal of Physics. (to be published). (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Asahi, H. Ogawa, K. Sakai et al.: "Nuclear Moments Measurements with polarzed Radioactive Beams"Proceedings of the Fourth International Workshop on Laser Spectroscopy on Beams of Radioactive Nuclei. (in press). (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] K. Asahi: "Nuclear and fundamental physics with spin-polarized nuclei"Genshikaku Kenkyu. 44, No. 4. 45-63 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1999 Final Research Report Summary
  • [Publications] 酒井健二、内山靖人、旭耕一郎、他: "スピンフリップ磁気減速とUCNの生成"「冷中性子干渉実験の進展とその応用(III)」研究会報告書. KURRI-KR-35. 81-87 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] 内山靖人、旭耕一郎、酒井健二、他: "多段スピンフリップ磁気減速法による超冷中性子生成法の開発"Proc.of the 4th Workshop on Nuclear Physics and Fundamental Physics with Neutrons IV,March 1999,Tsukuba,Japan. KEK Proc 99-4. 187-209 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] H.Ogawa,K.Asahi,K.Sakai et al.: "Magnetic Moment and Electric Quadrupole Moment of the ^<18>N Ground State"Phys.Lett.B. 451. 11-18 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] K.Asahi,H.Yoshimi,K.Sakai et al.: "Fundamental Physics with Polarized Nuclear Spins - New Type of Spin Maser for the Neutron EDM Measurements"Czechoslovak Journal of Physics. 50(出版予定). (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] K.Asahi,H.Ogawa,K.Sakai et al.: "Nuclear Moments Measurements with Polarzed Radioactive Beams"Proceedings of the Fourth International Workshop on Laser Spectroscopy on Beams of Radioactiver Nuclei,Poznan,Poland,May 1999. (出版予定). (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] 旭耕一郎: "核スピンで探る基礎物理" 冷中性子干渉実験の進展とその応用(II)ワークショップ報告書. KURRI-TR-426. 88-95 (1998)

    • Related Report
      1998 Annual Research Report

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Published: 1998-04-01   Modified: 2016-04-21  

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