Abstract:
To investigate the magnetic properties of electrical contact between the
superconducting filaments in a multifilament tape, this paper studies the
vortex motion across a simpler planar model of the tape, namely an array of
superconducting film strips with shorted ends, a 'shunted-x-array'. The
vortex motion visualized by magneto-optical imaging is discussed when
external currents, magnetic fields, and both simultaneously are applied.
When transport current alone is applied, the flux distribution in the
shunted-x-array strips is very similar to that in a single strip. However, the
behaviour is completely different in the presence of an external magnetic
field. The induced current flows around the entire sample to shield the inner
region, while the vortices penetrate first into the outermost strips, and then
into the next strips in turn as the field increases. For this case, the flux
distribution is symmetrical about the central vertical line of the sample.
When current and field are simultaneously applied, the vortex penetration
into the sample is no longer symmetrical because the resultant current is not
a simple linear superposition of the induced and applied currents.
