Dynamic pulse hysteresis of magnetic devices

Abstract

Dynamic pulse hysteresis is defined as the instantaneous hysteresis of a magnetic device during the risetime of an applied pulse field. A method of measuring the dynamic pulse hysteresis of magnetic devices has been developed. The pulse hysteresis differs from the quasistatic hysteresis in its ability to display magnetic damping phenomena. By applying sampling technique the flux sensitivity of this method is extended to 10-4 Mx. The theoretical pulse hysteresis obtained by computer solution of Gilbert's equation is compared with the measured pulse hysteresis of a 10 000-Å uniaxial Permalloy film at 7-nsec risetime. From the comparison, the intrinsic damping constant of the film is determined to be 8×108 sec-1. The measured pulse hysteresis of a ferrite core in a time-limited partial switching mode is also presented. © 1965 The American Institute of Physics.