Experimental Study on a Current Sweep Method Combined With Thermal Cycle for Mitigation of Screening Current-Induced Field in a Conduction-Cooled REBCO Magnet

Given that REBCO wire is typically manufactured as a tape, it is possible for REBCO magnets to exhibit a relatively larger screening current-induced field (SCF). It is well known that the SCF in an REBCO magnet can be effectively reduced by the so-called current sweep method. However, it requires an overshooting in the magnet current, often close to the magnet's critical current, to effectively suppress the SCF, which may not be favored in terms of operation reliability. In this study, we experimentally validated an alternative approach which mitigates the SCF using thermal cycling together with the current sweep reversal. Well known is the fact that the large load factor, defined as the ratio of operating current to critical current of an REBCO magnet, deteriorates the SCF impact on field uniformity. The key idea is to increase the magnet temperature to increase the effective load facto…