Abstract
A new method for producing a step-like change of magnetic field has been developed by using magnetically-coupled two superconducting coils and two superconducting switches. In this method, since the change of the magnetic field occurs as a transition from a stable persistent-current state to another, no power supply is required in the two states to keep the magnetic fields constant. Also in this method, no unstable transient phenomenon is generated in principle, and a sharp step-like change of magnetic field is produced. A step magnetic-field change of 2.1T was experimentally obtained in a time interval of about 600ms without any unstability. It is expected that the time constant of the transition can be reduced more than two orders of magnitude when the characteristics of the superconducting switches are improved. The present method is especially useful in obtaining a large change of high magnetic field.
