Title :
Magnetic flux diffusion through HTS shields
Author :
Havenhill, A.D. ; Wong, K.W. ; Fan, C.X.
Author_Institution :
Dept. of Earth Sci. & Phys., South Dakota Univ., Vermillion, SD, USA
fDate :
6/1/1998 12:00:00 AM
Abstract :
Slow field leakage in a polycrystalline superconducting cupshield placed in an external axial field (H/sub ext/) much weaker than H/sub C1/ shows a diffusive time dependence with a time scale of 10/sup 2/ s. As the field strength increases but is still less than H/sub C1/, a logarithmic time dependence of 10/sup 2/ s time scale is observed. It is shown that this logarithmic time dependence is a result of flux line diffusion between superconducting grains rather than fluxoid avalanches or flux bundle creep.
Keywords :
critical current density (superconductivity); high-temperature superconductors; magnetic flux; magnetic shielding; HTS shields; diffusive time dependence; external axial field; field strength; flux line diffusion; logarithmic time dependence; magnetic flux diffusion; polycrystalline superconducting cupshield; slow field leakage; superconducting grains; Astronomy; Creep; High temperature superconductors; Magnetic flux; Magnetic flux leakage; Magnetic shielding; Physics; Superconducting magnets; Superconducting materials; Type II superconductors;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
