Commissioning of HTS Adapter and Heat Exchanger for Testing of High-Current HTS Conductors

In the EDIPO test facility, superconducting cables with a current carrying capacity up to 100 kA can be tested in a background field of 12.5 T. A NbTi transformer, which is operated at ≈4.5 K, provides the sample current of up to 100 kA. The high-temperature superconductor (HTS) adapter, which is similar to an HTS current lead, connects the HTS sample under test and the NbTi transformer and limits the heat flux between them to less than 20 W at a warm end temperature of 50 K. Helium of 4.5 K and 10 bar supplied by the refrigerator is warmed up to temperatures up to 60 K, by means of heaters and a counterflow heat exchanger (HEX). The HEX ensures that the warm helium leaving the HTS sample can be returned as cold gas with less than 20 K to the refrigerator. The commissioning of the HTS adapter and the HEX has been performed together with the test of a 60-kA class HTS cable manufactured at CRPP. The results of the commissioning of the HEX and the HTS adapter are presented.