Magnetic Forces Relaxation Step Change Characteristics of YBCO Bulk with Mechanical Impact Load over a NdFeB Guideway

• Published in: Journal of superconductivity and novel magnetism Vol. 23; no. 2; pp. 193 - 198
• Main Authors: Lu, Yiyun, Wang, Jiasu, Wang, Suyu, Dang, Qiaohong
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-02-2010; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic Materials; Magnetic properties; Magnetism; Original Paper; Physics; Physics and Astronomy; Properties of type I and type II superconductors; Strongly Correlated Systems; Superconductivity; Vortex lattices ,flux pinning, flux creep; 85.25.-j; YBCO bulk; Magnetic relaxation; Permanent magnet guideway; Impact load; Flux line; Critical state model; Pinning; Flux; Permanent magnets; Iron alloys; Neodymium alloys; Boron alloys; High-Tc superconductors; Guideway; Applied load; Barium Copper Yttrium Oxides Mixed; Mechanical shock; Magnetic levitation
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-009-0514-5

Magnetic force relaxation of YBCO bulk above the NdFeB permanent magnet guideway (PMG) with impact load has been investigated. An experimental setup has been built using a single YBCO bulk and a symmetrical center NdFeB PMG. There are two experimental methods: the case of magnetic levitation force relaxation measuring perturbed with impact load in zero-field-cooling (ZFC); and the case of magnetic levitation and guidance force relaxation measuring synchronously perturbed with impact load in field-cooling (FC). The results show that there is magnetic levitation and guidance forces relaxation step change at the time of the impact load. Two times impact loads are applied for each method. The first step change range is much larger than the second one. The Bean critical model and Anderson–Kim theory are used to analyze it.