New excitation method of superconducting magnet using LC resonance

An LC resonant circuit composed of a superconducting coil and a capacitor bank can be utilized for a new excitation method of superconducting magnet. If an AC voltage with resonant frequency is applied to the circuit, an AC current builds up inside the circuit. After the amplitude of the magnetic current reached a high enough level, by activating a persistent current switch, a finite DC current could be established in the magnet. In such a process, except for the transient component, the current from the power source is very small due to the good resonant characteristics of the circuit. A preliminary experiment using a small scale magnet has been carried out, and the fundamental idea of this method was confirmed. (C) 1997 Elsevier Science Ltd.