FerroElectric Generator Development for Prime Power Supply (A19-144)

The primary technical objective for the Phase II research is to demonstrate a functional FEG-based prime power supply suitable for driving very compact, directed-energy systems at TRL-6. The US Army has programs that require on-demand, primary power supplies in very restrictive environments.  These power supplies must be capable of supplying voltages as high as 60 to 70 kV.  The energy outputs must be 5 joules or more.  The active time for this power supply is ≤10 ms for increased reliability and circuit compatibility.  Mission requirements require that the power supply must be quiescent and stable under most environments.  When activated, the lead time needs to be ≤10 us.  Mission size restrictions suggest a total geometry volume of ≈25 in3.  Therefore, the Army is seeking prime power supply designs appropriate for several classes of directed-energy munitions.  While multi-use power supplies are desirable, a single-shot power supply design will satisfy all requirements of the solicitation. From the answers to questions to the sponsor, we know that the load for this power supply is a capacitor.  Given the required energy of 5 J, the size of this capacitor is ~2 nF, if the charge voltage is 70 kV.  Since a single-use power supply is acceptable, one can then consider using an explosive-driven power supply.  With the volume restriction, a Flux Compression Generator (FCG) is ruled out for two reasons.  First, an FCG is not, of itself, a prime power source, and second, including the prime power for a small capacitor with a needed volume for the FCG would simply be too large to fit the volume requirement.  Another possibility would be a FerroMagnetic Generator.  While an FMG can certainly be used as prime power, the energy available from the FMG is too small to satisfy the solicitation requirement without amplification, and the FMG volume will likely be about the stated volume – without room for an amplifier stage.  Additionally, FMGs are typically considered current sources, with associated lower impedances.  Finally, a FerroElectric Generator (FEG) should supply the electrical requirements, but only if the basic FEG is redesigned to more efficiently use the ferroelectric material for charge extraction at higher voltage, while avoiding generator breakdown – historically a limiting factor for energy delivery.  Further, an FEG can be designed to fit into the volume specified.