Characterization of inductance gradients in electromagnetic launchers

We reapproach the characterization of inductance gradient and current distribution in electromagnetic rail launchers with multiple brush armature. 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 develop an experimental analysis on a rail launcher prototype supplied by a high-voltage high-power capacitor bank. Experimental results are performed under static condition of the armature and they are in agreement with theoretical calculations.