HIGH-ACCURACY MEASUREMENTS ON RAILGUNS

We have attempted the improvement Of several different measuring metho ds used in railguns. These technics cover several topics like measurem ent of main current, voltages on switches and inductors and magnetic f ield distribution with B-dot probes. A Rogowski coil coupled to a new type of electronic circuit (called ''switching gain circuit'') allows an accurate measurement of resistance as low as a few m Omega in a pul sed power facility. Low voltage measurement in a high voltage circuit (100 V in comparison to 10 kV) have been made on semi-conductors and s witching components in pulse power system. Special circuits rejecting the high voltage have been developed. Finally we describe the measurem ents of the current distribution along a metallic projectile moving in a railgun by mean of previously calibrated B-dots.