Title :
Relaxation of magnetic shielding tubes of sintered YBCO
Author :
Wang Jingrang ; Jianping, L.I. ; Wanming, Yang ; Lian, Zhou
Author_Institution :
Northwest Inst. for Nonferrous Metal Res., Shaanxi, China
fDate :
3/1/1991 12:00:00 AM
Abstract :
Magnetic shielding properties have been studied for sintered YBaCuO tubes of different size. The maximal DC shielding field reached 3.7 mT. It is found that the total shielding effect is not simply additive for two tubes put together. The shielding effect depends on temperature and the position in the external field, and the trapping field was found to be damped linearly with the logarithm of time, exhibiting flux creep behavior. The average persistent current density was about 102 A/cm2. The potential barrier was estimated to be 0.78 eV and 0.76 eV for weak-link region and grain, respectively, according to Anderson´s model of thermal activation from the damping rate of persistent current
Keywords :
barium compounds; critical current density (superconductivity); flux creep; high-temperature superconductors; magnetic shielding; yttrium compounds; Anderson´s model; average persistent current density; damping rate; flux creep; grain; high temperature superconductivity; magnetic shielding relaxation; maximal DC shielding field; potential barrier; sintered YBaCuO tubes; thermal activation; trapping field; weak-link region; Coils; Damping; Electrical resistance measurement; Hall effect devices; Lakes; Magnetic field measurement; Magnetic shielding; Persistent currents; Powders; Yttrium barium copper oxide;
Journal_Title :
Magnetics, IEEE Transactions on
