Experimental Research on the Bitter-Like HTS Magnet Energized by an Inner Flux Pump

Abstract

High-temperature superconducting (HTS) 2G conductors have been extensively applied in high magnetic field. This paper presents a novel excitation method of the Bitter-like HTS magnet for a stack of the RE-Ba-Cu-O (RE = rare earth) annular plates. The Bitter-like HTS magnet was energized by a flux pump composed of a copper solenoid coil and a pulsed triangular waveform current source. A single REBCO annular plate's critical current Ic was measured in 77 K (LN2 bath) in self-field, and the structure design of the whole flux pump, the transient process of the induced magnetic field, and the magnetic field attenuation of the Bitter-like HTS magnet under different excitation methods were described and tested in 77 K. Results show that the Bitter-like HTS magnet energized by a flux pump can realize closed-loop operation, and the flux pump with variation pulsed current values has an impact on the induced magnetic field attenuation in the Bitter-like HTS magnet. Furthermore, the flux pump making use of the inner excitation method has a faster excitation speed than the outer excitation method in our previous study.