Speaker
Description
Currently, The National High Magnetic Field Laboratory (NHMFL) is in the process of developing a 40 T High Temperature Superconducting (HTS) user magnet, and for the magnet development, it is essential to evaluate the performance of a large number of HTS modules in the future. Typically, each HTS module requires performance evaluation after winding and before being assembled into a magnet. While testing under Liquid Helium (LHe) conditions, where the final product will operate, is ideal, due to cost and time constraints, inspection under LN2 conditions is known to be a more efficient approach. However, since the final operation of HTS magnets is conducted in LHe and the performance of HTS tape, which plays a critical role in the module's performance, does not exhibit linear behavior between Liquid Nitrogen (LN2) and LHe temperatures, discrepancies arise between the performance of the HTS module verified under LN2 conditions and its performance under LHe conditions. To address the above issue, a performance evaluation system for HTS modules based on the conduction cooling method was developed. This paper describes the design, construction, and test results of the system. The constructed conduction cooling-type HTS module testing system uses two two-stage GM cryo-coolers as the primary cooling source. The 1st stage cold head of the cryo-cooler is responsible for cooling the metal current leads and radiation shields, and the bottom side of the HTS leads. The 2nd stage temperature section is responsible for cooling the Oxygen Free Copper (OFCu) cooling plate and top-side of the HTS leads. The HTS test module is cooled through the OFCu cooling plate. The HTS module testing system controls the temperature of the HTS module under testing from 4 K to 30 K and can supply an operating current of up to 800 A. All operating parameters of the HTS module test system are controlled and recorded using a Data Acquisition (DAQ) system based on LabVIEW.
ACKNOWLEDGMENTS
This work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-2131790, DMR-2128556, and the State of Florida.
