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Description
The persistent current switch (PCS) is a key component for enabling persistent current mode operation in superconducting magnets. Based on our previous research, this study proposes a heater-triggered semi-PCS with an ultrahigh switching-off resistance, fabricated using laser cutting and suitable for REBCO tapes. After chemically etching tapes, a designated path was cut into the exposed superconducting layer using a laser, forming a switch with ultrahigh resistance. With the optimized structure, the semi-PCS operates at 100 K and achieves an switching-off resistance of up to 19 Ω over a 10 cm effective length, with an input power of only 2 W. Compared to our earlier ohmic-level semi-PCS, the switching temperature is 10 K lower, with a fivefold increase in switching-off resistance and a sevenfold improvement in switching speed. Additionally, the semi-PCS was connected via copper bonding joints to an insulated coil wound from REBCO tape provided by SST. The advantages of semi-PCS with high switching-off resistance over traditional semi-PCS were demonstrated during magnetization of this high-inductance coil.
Keywords: ultrahigh switching-off resistance, high-temperature superconductor, semi-persistent current switch, Copper bonding joints
