Characterization of inductance gradient and current distribution in electromagnetic launchers

We reapproach the characterization of the inductance gradient and the current distribution in electromagnetic rail launchers with multiple brush armatures. A measurement procedure based on the use of a loop system mutually coupled with the launcher is illustrated for the case of a two-brush armature. We show how to estimate the current distribution between the brushes following the basic rules of the partial-inductance method. To test the proposed procedure, we performed an experimental analysis on a rail launcher prototype supplied by a high-voltage high-power capacitor bank. Experimental results were obtained under the static condition of the armature, and they are in agreement with theoretical calculations.