Speaker
Description
We will present the status of commercial production of 2G HTS Roebel cables along the advanced “Punch-and-Coat” route.
The “Punch-and-Coat” approach to 2G HTS Roebel cable fabrication was recently developed in collaboration between KIT and SuperOx. The approach is to prepare a meander-shaped strand for Roebel cable by mechanical stamping of silver-finished 2G HTS wire, and then electroplate stabilising surround copper coating onto the strand. As a result, the wire architecture, along the entire strand, is fully encased in copper and is thus geometrically symmetrical and protected from delamination. Moreover, the copper coating, added after punching, smoothens the punching burr on the substrate, making it no hazard for the adjacent strands. The “Punch-and-Coat” strand fully retains its original critical current after 200 thermal cycles between 77 K and room temperature. Before the cable is assembled, the strands are routinely characterised along the entire length by the magnetic non-contact and direct transport critical current measurements at 77 K.
SuperOx has successfully commercialised the fabrication of “Punch-and-Coat” 2G HTS Roebel cables, delivering multiple cables for HTS insert coils for high field accelerator magnets, as well as for stator coils for HTS rotating machines.