Study of low energy muon collision with a drift tube method

• Project/Area Number: 16K17546
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Quantum beam science
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Matoba Shiro 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 特別助教 (80535782)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2018: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000); Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2016: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: ミュオン / 陽電子 / 軌跡検出器 / 移動度 / 移動管 / 運動量移行断面積 / 移動管法 / 量子ビーム

Outline of Final Research Achievements

The purpose of this research is to derive the momentum transfer cross sections between muon-neutral gas molecules in the thermal energy region by performing muon mobility measurements in a gas using a drift tube method. We fabricated a drift tube with a trajectory detector that detects high-speed positrons that muon decays in the gas.
The momentum transfer cross sections were derived by measuring the positive muon stop position distribution in helium gas at room temperature and 1 atmosphere pressure at the Muon S-line at the J-PARC Materials and Life Science Experiment Facility. It has been suggested that a muon can be regarded as a hydrogen isotope in collision phenomena in helium gas at room temperature.

Academic Significance and Societal Importance of the Research Achievements

本研究の意義は以下の通りである．
１，緩衝気体によるミュオン減速と崩壊陽電子軌跡検出器を組み合わせることにより，レーザー等の大掛かりな装置を用いずともmeV領域のミュオン原子物理学研究が可能であることを示した．２，熱エネルギー領域の気体中での正ミュオンの振る舞いについて，室温では水素同位体と見なしても差し支えない事が示唆された．環境中のミュオンの挙動について情報を与えるものであり，詳細な第一原理計算による検証が待たれる．

Research Products

• [Journal Article] Development of Drift Tube for Study of a Quantum Mechanical Scattering of Muons in a Gas (2018)
  • Author(s): S. Matoba, L. Hua, N. Kawamura, and K. M. Kojima
  • Journal Title: KEK-MSL REPORT Volume: 1
• [Presentation] 気相中のミュオン移動度の測定 (2018)
  • Author(s): 的場史朗
  • Organizer: イオン移動度研究会
  • Invited
• [Presentation] 気相中のミュオン移動度測定装置の開発 (2018)
  • Author(s): 的場史朗，李華，河村成肇，小嶋健児
  • Organizer: 日本物理学会2018年秋季大会
• [Presentation] 気相中のミュオン移動度測定装置の開発 (2018)
  • Author(s): 的場史朗, 小嶋健児, 李華, 河村成肇
  • Organizer: 原子衝突学会第43回年会
• [Presentation] ミュオン移動度測定に向けた装置開発 (2017)
  • Author(s): 的場史朗，小嶋健児，李華，河村成肇
  • Organizer: 原子衝突学会第42回年会
• [Presentation] Development of an apparatus for muon mobility measurement in rare gases (2017)
  • Author(s): Shiro Matoba, Naritoshi Kawamura, Kenji Kojima
  • Organizer: XIX International Workshop on Low-Energy Positron and Positronium Physics
  • Int'l Joint Research
• [Presentation] 気相中のミュオン移動度測定のための装置開発 (2017)
  • Author(s): 的場史朗, 小嶋健児, 李華, 河村成肇
  • Organizer: 第6回イオン移動度研究会
• [Presentation] Equipment development for muon mobility measurement in rare gases (2017)
  • Author(s): Shiro Matoba, Naritoshi Kawamura, Kenji Kojima
  • Organizer: 30th International Conference on Photonic, Electronic and Atomic Collisions
  • Int'l Joint Research
• [Presentation] 希ガス中におけるミュオン移動度測定に向けた装置開発 (2016)
  • Author(s): 的場史朗、小嶋健児，河村成肇
  • Organizer: 原子衝突学会第41回年会
  • Place of Presentation: 富山大学(富山県・富山市)
  • Year and Date: 2016-12-10