Performance of Epoxy-Impregnated High Temperature Superconducting (HTS) Coils Inside a 16 Tesla Large Bore, Low Temperature Superconducting (LTS) Magnet

This paper presents the design, construction and test results of HTS insert coil sets made of YBCO/BSCCO conductors. The HTS insert coils are designed to produce a field of up to 6 T to 9 T at 4 K in a 110 mm bore in a background magnet of 16T. The coils use over 2.5 km of 4 mm- wide Second Generation (2G) HTS conductors provided by Sumitomo Electric, Fujikura and others. The coil set, when inside the 16 T LTS outset, generates a combined field of up to 25 T and provide a practical magnet for research use.

Voltage taps are installed to perform a series of V-I measurements at various magnetic fields and temperatures including a basic test at ~77 K with liquid nitrogen, as well as at 4.2 K.  The magnet is operated in liquid helium with cryocoolers used to cool the system down and provide near zero helium consumption.   The coil is designed to be able to survive a quench at high field in a large stress environment with no significant degradation.