Explosive-driven magnetic flux cumulation by the propagation of shock-compressed conductive region in highly porous metal powders

The explosive-driven magnetic flux cumulation process by the convergence of high-pressure shock waves in highly porous metal powders has been studied experimentally. The field-multiplication ratio depends mainly on the initial density of powder, although the flux compression signal has been detected for all the powders tested. Extremely light aluminum powders of initial density, of about 0.41 g/cm3 is shown to be the most promising within this experiment. The time evolution of flux density, i.e., B(t) for the case of light metal powders (Al and Mg), can be well approximated by the inverse power law. The results are explained by the magnetohydrodynamic theory.