Meson Science Research with Intense Muon Beam

利用强介子束进行介子科学研究

• 批准号: 01044036
• 负责人: YAMAZAKI Toshimitsu
• 金额: $ 18.24万
• 依托单位: The Univetsity of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01044036/
• 关键词: Meson; Muon; muSR; Antiproton; 高温超伝導体; ミュエスア-ル; 有機物半導体; 中間子原子; 量子拡散

In 1988 a new slow and D. C. negative muon channel was completed by the cooperative work between UTMSL (The University of Tokyo, Meson Science Laboratory) and TRIUMF (Tri-University Meson Facility, Vanconver, Canada) with the help of the Grant-in-Aid for special Project Research on Meson Science from Mombusho. Now, this channel located in the meson area of TRIUMF gives an opportunity for Japanese and international researchers to use the world strongest negative muon beam.With support of the present "KOKUSAI-GAKUJTYUTSU-KENKYU", many important muon experiments have been carried out by using this new negative muon channel.The importance of the oxygen in the high Tc superconducting materials have been emphasized by many theoreticians and also by many experimentalists, for which there exist a few proper probes. The negative muon captured at the oxygen nucleus is one of the most efficient microscopic probe which can detect the local electric and magnetic fields at the oxygen site.The joint … More group of UTMSL-RIKEN-Yamanashi University has found two different negative muon signals corresponding to different oxygen sites, using the very pure single srystal of LaSrCuO. The paramagnetic shift and the relaxation rate are studied for the various concentrations of the doped impurities. There temperature dependence as well as crystal axes dependences are obtained. The parts of this experiment have been reported at the 5th International Conference of muSR (Oxford, 1990) and International Conference on High Tc (Kanazawa, 1991).Also to the other group of high Tc materials YBzCuO, negative muon study was applied. There, rather small amplitude of mu^-SR signal was found for the sample which shows superconductivity but a fairly large signal was obtained for the sample which shows antiferromagnetic ordering. In order to obtain the general understanding of the negative muon behavior in the magnetic oxides a systematic study are carried out on the various 3d-metal oxides.On the other hands, the positive muon has been established as a unique and proper microscopic probes to detect antiferromagnetic ordering or weak magnetic local field, which is very difficult to be observed with another method. With this reason mu^+SR has intensively been applied on studiesof high Tc superconductors. The study was extended to new high Tc superconducting materials Bi_2Sr_2YCuO_y, Bi_2(Sr_<1-x>, La_x)_2Cuo_y, YBa(Cu_<1-x>, Cu_x)O, PrCuO, GdCeCuO etc. Another achievement is the success of mu^+SR measurement for the the high Tc material located inside the thick walled chamber for high pressure studies up to 0.6Gp.The study of Peierls instability transition has been performed for one dimensional polymers polyacetylene, using a negative muon captured at carbon forming a substitutional boron-like impurity.The interaction of slow muon and the thin foils was studied by detecting the distribution of secondary electron numbers. From the average number distribution of emitted electrons, charge asymmetric effect was obtained. The charge symmetric effect [n(mu^+)-n(mu^-)]/[n(mu^+)+n(mu^-)] called the Barkas effect (asymmetric effect in stopping power) was obtained for the momentum region 5 Mev/c - 12 Mev/c.New exploratory experiments on meson production have been carried out at TRIUMF, CERN, GSI and Saclay. The most exciting result is also the observation of delayed antiproton annihilation in helium medium. Less

1988年，引进了一种新的慢生和D. C.负μ介子通道是由UTMSL（东京大学介子科学实验室）和TRIUMF（加拿大Vanconver三大学介子设施）在Mombusho介子科学特别项目研究资助金的帮助下合作完成的。现在，这个位于TRIUMF介子区的通道为日本和国际研究人员提供了使用世界上最强的负μ子束的机会。在目前的“KOKUSAI-GAKUJTYUTSU-KENKYU”的支持下，利用这种新的负μ子通道进行了许多重要的μ子实验，氧在高温超导材料中的重要性已被许多理论工作者所重视，也被许多科学家所重视。实验主义者，有几个合适的探针。在氧原子核处俘获的负μ介子是探测氧原子核处局域电场和磁场的最有效的显微探针之一， ...更多信息 UTMSL-RIKEN-Yamanashi大学的一个研究小组利用非常纯的LaSrCuO单晶，发现了对应于不同氧位的两种不同的负μ子信号。的顺磁位移和弛豫率的研究为各种浓度的掺杂杂质。有温度依赖性以及晶轴依赖性。本实验的部分内容已在第五届国际μ SR会议（Oxford，1990）和国际高Tc会议（金泽，1991）上作了报道。在那里，对于显示超导性的样品，发现μ ^-SR信号的振幅相当小，但对于显示反铁磁有序的样品，获得了相当大的信号。为了对磁性氧化物中的负μ子行为有一个全面的了解，我们对各种3d金属氧化物进行了系统的研究，另一方面，正μ子已经被确立为一种独特而合适的显微探针，可以用来探测反铁磁有序或弱磁局域场，这是用其他方法很难观察到的。因此，μ ^+SR在高温超导体的研究中得到了广泛的应用。本文的研究工作扩展到了Bi_2Sr_2YCuO_y、Bi_2（Sr_<1-x>，La_x）_2CuO_y、YBa（Cu_<1-x>，Cu_x）O、PrCuO、GdCeCuO等新的高温超导材料。另一项成果是在厚壁室中成功地测量了高Tc材料的μ ^+SR，用于0.6Gp的高压研究。使用在碳处捕获的负μ介子形成替代的硼，通过测量二次电子数的分布，研究了慢μ介子与薄箔的相互作用。从发射电子的平均数分布，得到电荷不对称效应。在动量为5 Mev/c - 12 Mev/c的范围内，得到了电荷对称效应[n（mu ^+）-n（mu ^-）]/[n（mu^+）+n（mu^-）]，称为Barkas效应（阻止本领的非对称效应）。最令人兴奋的结果也是在氦介质中观察到延迟的反质子湮灭。少

项目成果

S. Ikehata, et al.: "Lattice Instability in Polyacetylene probed by mu ^-Spin Resonance" Synthetic Metals.28. D275-D280 (1989)

S. Ikehata 等人：“通过μ-自旋共振探测聚乙炔中的晶格不稳定性”Synthetic Metals.28。

H. Kitazawa, et al.: "Negative Muon rotation studies on single crystal La_2CuO_<4+>delta above T_n" Physica. C185-189. 1087 (1991)

H. Kitazawa 等人：“T_n 以上单晶 La_2CuO_<4>δ 的负 μ 子旋转研究”Physica。

K. Nagamine et al.: "Design, Construction and Performance of the Superconductory Muon Channel at TRIUMF" 科研費特定研究「中間子科学」報告集「Meson Science」. 1. 9- (1990)

K. Nagamine 等人：“TRIUMF 超导 μ 子通道的设计、构造和性能”科学研究补助金“介子科学”报告集“介子科学”1. 9- (1990)。

T.Yamazaki et al.: "Pion-Transfer Reaction Spectroscopy of Inverse Kinematics for Studies of Deeply-Bound Pionic Atoms in Heavy Nuclei" Nucl.Instr.Meth.A292. 619 (1990)

T.Yamazaki 等人：“用于研究重核中深度结合的π原子的逆运动学π离子转移反应光谱”Nucl.Instr.Meth.A292。

N.Nishida et al.: "μ ^-SR Studies of Oxide-Superconductors" Hyperfine Interactions. 65. 1027-1034 (1990)

N. Nishida 等人：“氧化物超导体的μ^-SR 研究”超精细相互作用。65. 1027-1034 (1990)