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西村 昇一郎*; 鳥居 寛之*; 深尾 祥紀*; 伊藤 孝; 岩崎 雅彦*; 神田 聡太郎*; 川越 清以*; Kawall, D.*; 河村 成肇*; 黒澤 宣之*; et al.
Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08
被引用回数：13 パーセンタイル：83.13(Optics)As a method to determine the resonance frequency, Rabi-oscillation spectroscopy has been developed. In contrast to conventional spectroscopy which draws the resonance curve, Rabi-oscillation spectroscopy fits the time evolution of the Rabi oscillation. By selecting the optimized frequency, it is shown that the precision is twice as good as conventional spectroscopy with a frequency sweep. Furthermore, the data under different conditions can be treated in a unified manner, allowing more efficient measurements for systems consisting of a limited number of short-lived particles produced by accelerators such as muons. We have developed a fitting function that takes into account the spatial distribution of muonium and the spatial distribution of the microwave intensity to apply this method to ground-state muonium hyperfine structure measurements at zero field. It was applied to the actual measurement data, and the resonance frequencies were determined under various conditions. The result of our analysis gives 
= 4 463 301.61 
0.71 kHz.
Strasser, P.*; 阿部 充志*; 青木 正治*; Choi, S.*; 深尾 祥紀*; 東 芳隆*; 樋口 嵩*; 飯沼 裕美*; 池戸 豊*; 石田 勝彦*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
被引用回数：13 パーセンタイル：99.06(Quantum Science & Technology)High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.
勝山 幸三; 豊田 裕昌*; 永峯 剛
JAEA-Technology 2006-004, 30 Pages, 2006/02
JAEA-Technology-2006-004.pdf:2.44MB
高速炉燃料の被覆管は、高温,高速中性子下で照射され、その使用期間にわたって健全性を確保する必要がある。このためには被覆管の寿命予測が不可欠であり、特に熱過渡時の被覆管破損限界を見極める必要がある。本研究では、高速炉で照射した燃料ピンを対象とした熱過渡試験装置のホットセルでの実現性等について検討するとともに、実際に装置の実現性を見極めるためにモックアップ試験を実施した。その結果、本装置の加熱系には、高周波誘導加熱方式が最も有望であり、これにより加熱系を水冷却することなく、炉内を想定した燃料ピンの軸方向温度分布が再現できる見通しが得られた。さらにモックアップ試験結果から、加熱系に冷却機構を付加しない状況においても、急速加熱試験により被覆管表面の温度が最高で1100
Cまで到達することを確認した。また、被覆管表面温度を850Cの一定にして、1時間保持する高温保持試験も可能であることが確認できた。
