Use of the aluminum powder cascade technique to stabilize liner implosions

Electromagnetic flux compression requires high-quality liners, with copper being a much more effective material than the aluminum used in previous experiments at Loughborough for producing fields of 300 T. Unfortunately, similar small-size copper liners cannot be economically manufactured with sufficiently precise tolerances to prevent the development of liner instabilities during an implosion, leading to a much lower magnetic flux density than anticipated. The paper describes how the performance can however be dramatically improved by the use of an aluminum powder cascade, and presents results showing that the use of this technique has enabled flux densities up to 350 T to be generated using only a 70-kJ capacitor bank. Index Terms--Instabilities, liner implosions, phase transitions, ultrahigh magnetic fields.