H. Matsuzawa et al., Shielding of pulsed magnetic fields with already sintered 1 mu m sized powder-pressed Bi-based superconducting rings, APPL PHYS L, 78(24), 2001, pp. 3854-3856
To confirm a ferrite-core model for the superconducting rings (supertrons)
to focus and guide electron current beams, we examined a bismuth-based ring
into the configuration of which already sintered 1 mum sized 2223-phase po
wders were cold-isostatic pressed, No additional sintering was performed on
the ring. Although the four-probe dc electric resistance of the ring incre
ased with decreasing temperatures down to 77 K, the ring effectively shield
ed the self-magnetic field of single pulsed nanosecond-order electron curre
nts (similar to 340 keV, similar to1 kA, similar to 10 ns), below the T-c.
These results certainly support the model, and provide a clue useful in app
lications of bulk superconductors. (C) 2001 American Institute of Physics.