ARDEC transition armature study. Progress report No. 3, October 1--November 30, 1991

Abstract

This third report covers the period October 1 to November 30, 1991. During this period the authors: (1) fabricated a test fixture for studying hybrid armature brush behavior, (2) reactivated a 140kJ, 1MA capacitor bank, (3) reactivated 25 channels digital data acquisition and reduction system and (4) concluded the use of a DNA funded railgun would serve as the most expedient means to acquire a railgun test bed. Fabrication of a plasma brush test fixture for studying the formation, evolution and stability of plasma brushes was completed. The fixture will serve to study plasma brush parameters, such as brush length and voltage drop, as a function of initial solid foil mass, gap size and current concentration. A 4OkV, 168{mu}f, 140kJ capacitor bank capable of providing more than 1MA of current was reactivated. (The LLNL bank had been developed for opening switch research which was successfully completed.) The bank will be used to power the test fixture with 10{mu}s, flat top current pulses. A 25 channel LeCroy digital data acquisition system interfaced to an LSI-11 and a Mini VAX computer was reactivated and brought on line to record the B-dot signals, voltages and current data from the test fixture. An evaluationmore » of the most expedient means of obtaining a small bore railgun test bed for armature studies led to the conclusion that a portion of the DNA funded, LANL fabricated, LTS (Lethality Test System) railgun which was loaned to SNL, would be the best choice. A request to borrow the equipment for 3 years was initiated.« less