High precision tracking control for rapid cycling magnets

Watanabe, Yasuhiro  ; Tani, Norio  ; Adachi, Toshikazu*; Someya, Hirohiko*; Irie, Yoshiro*

Rapid cycling magnets are excited using a resonant circuit and the current waveform is a DC-biased sinusoidal pattern. However, non-linear characteristic of the magnet produces harmonic components in the magnetic field. The harmonic components are different for each type of magnet depending upon the degree of saturation, and it causes a tracking error. This paper proposes harmonic current control in the resonant circuit to reduce harmonic components in the magnetic field.