High currents in MCP BSCCO 2212 bulk material

[BAs an extension of the Melt Cast Process (MCP) the centrifugal casting technique is a flexible method for manufacturing Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ bulk parts. It provides large scale rings and tubes, needed for high current electrotechnical applications as current leads and inductive fault current limiters. Low resistance contacts are integrated right in the fabrication process. Intrinsic (self field free) current densities up to 4 kA/cm/sup 2/ (T=77 K) could be determined on small samples. Tubes with a diameter up to 70 mm and a length of 200 mm were investigated with respect to their DC and AC current carrying capability (I=7500 A, DC, 4 /spl mu/V/cm and I/sub eff/=8300 A, AC, T=77 K). This current essentially is limited by self field effects as is shown in a numerical simulation. The quenching behaviour is related to the shape and temperature dependence of the U(I)-characteristics. First applications, i.e. hybrid current leads with integrated MCP bulk parts, are presented.