High accuracy measurements on railguns

The authors have attempted the improvement of several different measuring methods used in railguns. These techniques cover several topics like measurement of main current, voltages on switches and inductors and magnetic field distribution with B-dot probes. A Rogowski coil coupled to a new type of electronic circuit (called a "switching gain circuit") allows an accurate measurement of resistance as low as a few m/spl Omega/ in a pulsed power facility. Low voltage measurement in a high voltage circuit (100 V in comparison to 10 kV) have been made on semiconductors and switching components in a pulse power system. Special circuits rejecting the high voltage have been developed. Finally, the authors describe the measurements of the current distribution along a metallic projectile moving in a railgun by mean of previously calibrated B-dots.<>