An experimental technique for characterizing the local variations of the vertical magnetic fields in bubble circuits

Abstract

A new experimental technique for characterizing the local fields associated with bubble propagation and control function circuit elements is presented. In this method, measurements of the local variations of bubble collapse field due to the circuit elements are made both statically and during high speed propagation. Short duration (∠1 μsec) increments of the bias field are applied synchronously with the drive field so that the effective bias field is temporarily increased as the bubble traverses a given location in the propagation circuit. By observing the minimum pulse amplitude necessary to produce collapse, the effective bias field can be determined. Such measurements are indicative of the strength of the local fields produced by the Permalloy elements.