Incident, Action, Recovery, and Recommissioning for the 4.5-MJ Pulsed Power Supply Located at the Electromagnetic Gun Facility, Barricade C, Aberdeen Proving Ground, MD

A 4.5-MJ capacitor-based pulsed power system (PPS), previously owned and operated by General Dynamics Land Systems in the early 1990s, was acquired by the U.S. Army Research Laboratory. The system was placed in storage in the late 1990s. It was recently modified and, in 2001, was placed back in operation at barricade C to operate with an electromagnetic (EM) railgun load. On 9 February 2006, a capacitor in module 4 developed an internal short while charged to 7.2 kV. Further inspection revealed arc damage at the center post terminal on 20 capacitors in nearby modules and some amount of rust on every capacitor case. After the incident, all modules were charged individually to 3.2 kV and discharged into a short. The data indicates that the damaged center posts likely occurred quite some time ago. New hardware was required to restore relevant capability to barricade C. The capacitors from the primary and essential basis for the system. The PPS must be capable of reliably delivering higher energy pulses. New capacitors using modem manufacturing techniques and improved dielectrics were purchased. New center posts were designed and replaced concomitant with the installation of new capacitors. Lastly, the bus work that connects the pulse-forming inductor to the pulse-forming-network output cable was replaced in order to decrease the number of bolted joints and increase reliability at high-energy operation. Upon completing the upgrade in hardware, each module was discharged into a short at the breech of the railgun at initial charge voltages of 3, 5, and 7 kV. Additionally, all 18 modules were sequentially discharged into the shorted breech. Lastly, firings using a railgun were completed without incident. All simulation models were updated as necessary throughout the commissioning process. The stored energy at the maximum charge voltage of II kV is now 5.2 MJ. The original document contains color images. Prepared in collaboration with Dynamic Science Inc., Aberdeen ,MD.