Development of 3-dimensional mapping system for high-resolution local field distribution at low temperatures

开发低温下高分辨率局部场分布的 3 维绘图​​系统

• 批准号: 07555002
• 负责人: SHIBAUCHI Takasada
• 金额: $ 4.48万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555002/
• 关键词: Local field distribution; Superconductor; Critical State; Critical current density; 磁気光学効果; 局所磁場分布; 高温超伝導体; 臨海電流密度; 磁場分布; 臨界電流; 電流分布

For the development of measurement systems for the local magnetic-field distributions at low temperatures, we use He-flow type cryostat, electromagnet cooled by liquid nitrogen, and a polarizing optical microscope, a CCD camera, and a video signal processor. By using magneto-optical technique, the local magnetic field is transformed to the light intensity and recorded to computers.For the 2-dimensional measurements, we succeeded in observing a critical state of high-temperature superconductors down to 4 K in the field range up to 2,500 Oe. The spacial resolution is 5,000 *, which is limited by the wave length of the light, and the field resolution was a few G.For the 3-dimensional measurements, the sample was moved against the indicator film by using a precision Z stage. In this case, however, we found that the temperature range was restricted down to 60 K beacuse of the thermal leak to the sample holder from the Z stage.Using this system, we can determine the current profile flowing in the sample under a magnetic field. In untwinned single crystals of Y- and Bi- based high temperature superconductors, we determined the anisotropy of the critical current densities in the superconducting planes (a and b axs) for the first time.

为了开发低温下局部磁场分布的测量系统，我们使用He流式低温恒温器、液氮冷却的电磁体、偏光光学显微镜、CCD相机和视频信号处理器。通过使用磁光技术，将局部磁场转换为光强度并记录到计算机中。对于二维测量，我们成功地在磁场范围内观察到了低至4 K的高温超导体的临界状态。至 2,500 Oe。空间分辨率为 5,000*，受到光波长的限制，场分辨率为几 G。对于 3 维测量，使用精密 Z 平台将样品移动到指示膜上。然而，在这种情况下，我们发现由于 Z 台到样品架的热泄漏，温度范围被限制在 60 K。使用该系统，我们可以确定磁场下样品中流动的电流分布。在Y基和Bi基高温超导体的非孪生单晶中，我们首次确定了超导平面（a轴和b轴）中临界电流密度的各向异性。

项目成果

T.Tamegai, S.Ooi, and T.Shibauchi: ""Vortex Lattice Melting and Peak Effect in Bi_2Sr_2CaCu_2O_"" Advances in Superconductivity. VIII. 587-590 (1996)

T.Tamegai、S.Ooi 和 T.Shibauchi：“Bi_2Sr_2CaCu_2O_<8 y> 中的涡晶格熔化和峰值效应”超导性的进展。

M.Sato, T.Shibauchi, S.Ooi, T.Tamegai, and M.Konczykowski: ""Recoupling of Decoupled Vortex Liquid by Columnar defects in Bi_2Sr_2CaCu_2O_"" Phys.Rev.Lett.79. 3759-3762 (1997)

M.Sato、T.Shibauchi、S.Ooi、T.Tamegai 和 M.Konczykowski：“Bi_2Sr_2CaCu_2O_<8 y> 中柱状缺陷对解耦涡流液体的重新耦合””Phys.Rev.Lett.79。

T.Shibauchi, M.Sato, S.Ooi, T.Tamegai, M.Konczykowski: ""Josephson Plasma Resonance in Bi_2Sr_2CaCu_2O_ with Columnar Defects"" Physica C. 282-287. 2427-2428 (1997)

T.Shibauchi、M.Sato、S.Ooi、T.Tamegai、M.Konczykowski：“具有柱状缺陷的 Bi_2Sr_2CaCu_2O_<8 y> 中的约瑟夫森等离子体共振”Physica C. 282-287。

T.Shibauchi et al.: "Observation of the Plasma Resonance across the Josephson-Coupled Layers in the Mixed State of Organic Superconductors" Physica C. 293. 73-76 (1997)

T.Shibauchi 等人：“有机超导体混合状态下约瑟夫森耦合层的等离子体共振观察”Physica C. 293. 73-76 (1997)

T.Tamegai, M.Sato, T.Yamamoto, S.Ooi, and T.Shibauchi: ""Dimensional Crossover of Quantum Collective Creep in Bi_2Sr_2CaCu_2O_"" Czech.J.Phys.46, Suppl.S3. 1733-1734 (1996)

T.Tamegai、M.Sato、T.Yamamoto、S.Ooi 和 T.Shibauchi：“Bi_2Sr_2CaCu_2O_<8 y> 中量子集体蠕变的维度交叉”Czech.J.Phys.46，Suppl.S3。