Design and testing of a 25-stage electromagnetic coil gun

Tetra has designed and fabricated a 25-stage prototype electromagnetic coil gun. To date, five stages have been successfully tested. Initial results track very well with predicted values. Each coil is sequentially fired as the projectile moves down the bore. A hybrid control system is used to measure the velocity of the projectile as it enters each coil and calculates the time-to-firing. Computer predictions based on this model indicate velocities greater than 3000 m/s can be achieved. Currently, the system has been tested with 10 kJ delivered to each coil. Solid dielectric switches are used to transfer the energy from each capacitor to the coils. Performance of the coil gun, computer modeling, and laboratory results are discussed.