Inductance gradient scaling experiments in an augmented railgun

A series of experiments were undertaken to determine whether the velocity performance of a separately augmented railgun scales linearly with the values of the inductance gradients. Two different railgun configurations which had the same containment, bore materials and bore preparation were used in these experiments. The low inductance gradient (LIG) gun had calculated values of L'=0.274 /spl mu/H/m, M'=0.249 /spl mu/H/m and the high inductance gradient gun (HIG) had calculated values of L'=0.425 /spl mu/H/m, M'=0.35 /spl mu/H/m. Experiments were conducted with nearly equal current levels in both guns using solid aluminum ring armatures. The measured velocities were used to determine whether the calculated inductance ratio was observed in performance. Frictional drag of the solid armatures complicated the data analysis but the increase in velocity performance was consistent with the calculated values of the inductance gradients.>