Determination of heater triggering parameters of superconducting power supply with series-connected double-pancake load

This paper presents determination of heater triggering parameters of high-T_c superconducting (HTS) power supply with series-connected double-pancake load, as well as analysis of its characteristics as determined through experiments. A HTS power supply consists of two heaters, an electromagnet, a Bi-2223 solenoid, and a Bi-2223 series-connected double-pancake load of 6.0 mH. The timing sequential control of two heaters and an electromagnet is an important factor to generate pumping-current in the pancake load. The thermal analysis of switching parts of the Bi-2223 solenoid according to the heater input was carried out. Based upon the analysis, the 8 A electromagnet current and the 1.5 A dc heater current were optimally derived, and 8 s and 20 s for the pumping period were selected in this experiment. In the experiment, the maximum pumping current reached about 24 A.