Measurement of the Current Distribution between Multiple Brush Armatures during Launch

This paper reports on a diagnostic technique developed to improve the understanding of the behavior of discontinuous armature configurations. The knowledge of the current distribution between the different conductors is of central importance for such configurations. The measurement technique is explained and experimental results obtained at the ISL-railgun EMA3 (muzzle velocity v₀ les 2 km/s, applied energy per shot E_prim < 0.6 MJ, I = 3 m, cal. = 15 mm times 30 mm, multiple metal fiber brush armatures) are presented. The results are discussed with the help of other experimental observations and by comparison with static finite element calculations.