Study of a CICC Copper Jacket Junction for MADMAX

For the Magnetized Disc and Mirror Axion eXperiment (MADMAX) project (Caldwell et al. 2017), we need some junctions between the coil double pancakes and with the current leads. MADMAX coils are skateboard double pancakes (Caldwell et al. 2017) placed in a static superfluid helium bath. For the first mock-up coil, called MAdmax Coil for Quench Understanding (MACQU), the current lead junctions were based on the W7X box design, but we got some limitation in these boxes at 80% of the critical current due to bad current distribution. To avoid this issue, for the MADMAX junctions design, we tried the simplest solution for a copper jacket cable in conduit conductor that consists to directly solder both jackets together. We made some resistance measurements on the MACQU mock-up conductor, and we defined semi-analytic formulae to extrapolate the result to the MADMAX conductor.