Current leads provide electrical current from the ambient to temperatures in the cryogenic range. While below 80 K high temperature superconducting (HTS) materials are used allowing nearly loss-free current transport, at higher temperatures normal-conducting current leads are employed. Due to ohmic losses in normal-conductors, these current leads are responsible for a significant fraction of the heat load onto the cryogenic system. Therefore, the thermal optimisation of normal-conducting current leads promises reduced energy demands of the overall cooling system for compact accelerators.
Current research at the organisational unit refrigeration and cryogenics is focused on the application of CMRC-cooled microstructured current leads in compact accelerator systems. Apart from experimental investigations of existing current lead protypes, a novel Compact Accelerator Systems Teststand (COMPASS) is to be built at ITTK. COMPASS will be a dedicated experimental facility to study further developed microstructured current leads with electrical currents ranging from a few hundred A up to 10 kA. Moreover, COMPASS will allow magnetic field measurements and the overall characterization of superconducting magnet systems like compact accelerator undulators.