COMSED 2 - recent advances to an explosively driven high power microwave Pulsed Power system

Continued efforts at the Center for Pulsed Power and Power Electronics at Texas Tech University have led to improvements to the design, testing, and performance of a high power microwave (HPM) system, which is sourced by Lithium-ion Polymer batteries, a polypropylene capacitor, and high energetics. An indirectly seeded two-stage helical flux compression generator (HFCG) produces electrical energies in the kilo-Joule regime into a low impedance inductive load, varying from 2 μH to 3 μH. This high current output of the explosively driven generator is conditioned with a pure silver-wire-based electro-explosive opening switch, which reaches voltage levels in excess of 300 kV into a 18 Ohm load. Upon reaching levels high enough to close an integrated peaking switch, this high voltage is sufficient to drive a reflex triode virtual cathode oscillator, also known as a Vircator, into radiation. The Vircator employed in the system has reached microwave radiation levels well over 100 Megawatts from a cavity volume of less than 5 Liters at a microwave frequency of a few GHz. The complete system is governed through a microcontroller that regulates seed and detonator charging levels as well as discharge times using built-in feedback diagnostics. The complete system aforementioned is constrained to 15 centimeter diameter and measures 183 centimeter in length with an overall volume of less than 34 Liters. No external power or vacuum pumping for the HPM tube is required. This report will discuss recent design advancements and improvements on the HPM system and its sub-components that include the compact seed source, HFCG, and the power conditioning system. Improved safety features implemented as well as novel diagnostic integration will be discussed as well.

I. INTRODUCTION

Presented are the results of an explosively driven pulsed power system designed to drive a high power microwave source, designed and developed at the Center for Pulsed Power and Power Electronics (P3E) at Texas Tech University [1]. The explosively driven system is composed of four subsystems that include a compact seed source (CSS) with an integrated fire-set [2], [3], a mid-sized dual stage helical flux compression generator (HFCG) [4], [5], [6], a power conditioning system, and a triode reflex virtual cathode oscillator (Vircator) as the microwave radiating source [7], [8], see Fig. 1 for system diagram.