Linear Flux Pump Device Applied to HTS Magnets: Further Characteristics on Wave Profile, Number of Poles, and Control of Saturated Current

This paper investigates further characteristics of the applied field profiles on flux pumping efficiency with the linear flux pump devices. During the measurement, the applied field was generated by copper coils controlled by a driver circuit to magnetize a YBCO superconducting coil. It was found that the duty ratio of the trapezoidal wave profile affected the pumping speed and the saturated current. We also investigated the effect of the wavelength, and it was discovered that the wavelength of 84 mm yielded the fastest speed, and the optimal wavelength did not depend on the width of the superconductor used for the flux pump. Moreover, the superconducting current in our measurement can be stabilized by maintaining the multiplication of the field strength and the applied frequency.