Induction coilgun for EM mortar

Abstract

The Defense Advanced Research Projects Agency is investigating electromagnetic (EM) guns for the next generation combat vehicle providing improved performance and survivability without the use of propellant. The two-year program was initiated in 2005 to design a coilgun and a railgun to launch an existing mortar round with an EM armature in laboratory conditions at speeds to increase range beyond current capabilities. This paper describes a laboratory coilgun system whose requirements are based on the Future Combat System Mortar Vehicle for indirect fire applications. Minimal adaptation has been necessary to existing mortar rounds with the armature and support structure necessary for EM coilgun launch. High magnetic field coils have been designed and tested at stress levels anticipated during launch. Recoil from the barrel of stacked coils will be managed by a conventional gun mount integrated to a catcher through a structural frame. Capacitor bank modules currently in fabrication and test utilize 1980’s technology capacitors, but new ideas in commercial components for switches, resistors and bus-work are investigated to lower cost. The firing system, which includes a projectile-sensing 94 GHz radar triggers the capacitor banks for optimal performance and precise muzzle velocity control, is also described.