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This Defense Intelligence Reference Document (DIA-08-0912-005) is dated 28 January 2010. The Defense Intelligence Agency's Defense Warning Office prepared it under the Advanced Aerospace Weapon System Applications Program. It gives an overview of pulsed high-power microwave sources and the technologies needed to build them, including insulation, cathode materials, high-voltage switching, pulse generators and antennas. The paper concludes that progress requires better cathodes, switching and insulation, and that compact ultrawideband antennas will remain difficult to build.
From the source:Release of 2026-09-18 Incident: 1/28/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys pulsed high-power microwave (HPM) source technology and argues that such systems remain of military interest because they can disrupt or damage electronic systems with short, intense electromagnetic pulses. The report reviews the main source types and the supporting technologies they depend on, including high-voltage insulation, switching, cathode materials, antennas, and pulse-power generation. It emphasizes the difficulty of building systems that are compact, efficient, and practical to field, since short pulse durations, antenna size, heating, detectability, and beam or signal quality all impose hard engineering limits. Its overall conclusion is that the technology has significant potential military value, but that further progress depends on advances in cathodes, predictive modeling, high-speed high-voltage switching, and low-loss insulation, while compact ultrawideband systems will remain difficult because of basic physical constraints on antenna design.
UNCLASSIFIED/ /PO" orr1e11tt U.!I! l>flt I pulse ceases. This mode requires much less optical power. Finally, PCSS switches may also be designed to operate in the avalanche mode. Switches operating in this mode are designed for higher voltages, and above some critical electric field, the switch remains closed even without optical energy. Carrier multiplication occurs because of the electric field, and the switching process sustains conduction. Optical energy required for avalanche mode PCSS switches is about l-l0pJ/cm 2 • Lock-on mode GaAs is the most commonly used PCSS switch for high-voltage applications. PCSS research at the University of Texas at Dallas (UTD) has resulted in promising techniques for improving the longevity of switches. High current densities in PCSS switches normally result in damage at the metal-semiconductor interface. Research at UTD using amorphic diamond coatings at the metal-semiconductor interface has resulted in significant lifetime improvement for the switches. The process uses a conformal coating with the hardness of natural diamond and extremely high electron emissivity originally called amorphous ceramic diamond and later shortened to simply amorphic diamond. Used in stacked Blumlein pulser configurations, these switches have demonstrated 150-ps switching speed at 100 kV and 105-shot lifetimes. High-Voltage Pulse Sources HPM sources have three basic components: • Electrical or explosive prime power. • RF generator. • Antenna. The prime power is supplied by means of pulsed-electrical-circuit Marx generators and transformer-based generators or by single-event explosively driven means. MARX GENERATORS Marx generators have been used for several decades now and have seen many improvements in their reliability and repetition rate capabilities. In a Marx generator, some number of capacitors, referred to as the number of stages, are charged in parallel. After the charge cycle is complete, gas switches located between each stage are triggered to conduction, and the capacitor configuration is changed to a series connection. The result is that the charge on each capacitor is multiplied by the number of stages, and the effective capacity is the stage capacitance divided by the number of stages. Because all inductances are also in series, the equivalent inductance is the sum of all circuit, switch, and capacitor inductances. One problem with Marx generator circuits is that approximately half the energy used is lost as heat in the charging resistance for each stage. Using inductive charging can lessen this problem, but care must be taken, since several LC loops can be formed, all of which resonate at different frequencies. The result can be extremely high voltages in circuit locations where these are not expected. This can be especially troublesome in high-repetition-rate circuits. UNCLASSIFIED/ fFOA QFFICiIOls. H&'li Qlslls.\' 15
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 37 pages are in the text index: search them above, or from the library's search.