Muon Spin Rotation Measurements of Off Axis Internal Magnetic Fields in Anisotropic Superconductors

技术摘要：利用介子自旋（muonSR）技术的新扩展，将从理论和实验两方面研究高温超导体（HTS）中的静态场和动态场。迄今为止，在高温超导中几乎所有的muonSR工作都集中在横向磁场测量上。这项工作的新发展将允许使用纵向场技术，即使平均内部场既不沿着也不垂直于光束轴。这项技术将用于探测垂直于平均磁场的小型内部磁场。实验将与理论确定的由横向场分布引起的倾斜紊乱进行比较。内部场相关时间的数据将用于开发这种运动的模型，这将有助于理解无序涡旋晶格熔化过程。非技术摘要：磁场沿涡旋轴进入高温超导体。理想情况下，这些漩涡是直的，并按规则的模式排列。然而，在现实中，这些漩涡倾斜，弯曲，并移动出规则的位置。这些涡旋的静态和动态失序需要被理解，因为它们会导致这些超导体中的能量损失。这种损耗反过来对潜在的超导装置，如高磁场磁体或输电线路产生不利影响。涡旋序、倾斜和运动的性质将从理论上和实验上进行研究。这项实验技术使用一种叫做μ子的基本粒子来感知超导体中的局部磁环境。＊＊＊

9321363 Kossler Technical abstract: Static and dynamic fields in high temperature superconductors (HTS) will be studied both theoretically and experimentally by new extension of muon spin rotation (muonSR) techniques. Nearly all muonSR work in HTS to date has focused on transverse magnetic field measurements. The new development in this work will allow use of the longitudinal field technique even though the average internal field is neither along nor perpendicular to the beam axis. This technique will be used to detect small internal fields, which are perpendicular to the average magnetic field. Experiments will be compared to the theoretically determined tilt disorder induced by the transverse field distributions. Data on internal field correlation times will be used to develop models for this motion which will aid to understand the disordered vortex lattice melting process. Non-technical abstract: Magnetic fields enter high temperature superconductors along axes of vortices. Ideally these vortices are straight and arranged in regular patterns. However, in reality these vortices tilt, flex, and move out of regular positions. The static and dynamic disorder of these vortices needs to be understood because they contribute to energy losses in these superconductors. Such losses in turn have detrimental effects on potential superconducting devices such as high field magnets or electrical transmission lines. The nature of the vortex order, tilt, and motion will be studied both theoretically and experimentally. The experimental technique uses the elementary particle called a muon to sense the local magnetic environment in the superconductor. ***