Conduction-Cooled HTS Current Leads for the SIS100 Corrector Magnets

The superconducting synchrotron SIS100 for the FAIR accelerator project requires 137 superconducting corrector magnets: chromaticity sextupoles, steerers, and multipole correctors. These corrector magnets are distributed along a circumference of 1083.60 m. The coils of the corrector magnets are individually powered and require all together 244 pairs of current leads with the rated current of 250 A dc. To reduce the heat load to the cold mass of the superconducting ring, the current leads will be designed by use of the HTS material with a heat sink at the temperature level of 50-80 K. Modern 2G HTS tapes with low thermal conductivity and high current density enable a compact design of the current leads cooled entirely by the thermal conduction of the copper parts. The first pair of the current leads has been fabricated and successfully tested at the GSI magnet testing facility. The experimental data are in good agreement with the calculated values. The design of the current leads is presented as well as the measured data.