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This Defense Intelligence Reference Document, dated 10 March 2010, was prepared by the Defense Intelligence Agency's Defense Warning Office under the Advanced Aerospace Weapon System Applications Program. It surveys the basics, experimental status, theory and possible uses of inertial electrostatic confinement (IEC) fusion, with emphasis on work at the University of Illinois Urbana-Champaign. It covers neutron sources, explosives detection and space propulsion. It ends by proposing a 12-gun hydrogen plasma experiment meant to show breakeven conditions for p-11B fuel.
From the source: Release of 2026-09-18 Incident: 3/10/10, 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 inertial electrostatic confinement (IEC) fusion, a relatively unconventional fusion concept that uses electric fields rather than the more established magnetic or laser-based approaches to confine ions, and it reviews both the underlying physics and the experimental work associated with the concept. The report emphasizes that IEC may have nearer-term value as a compact neutron, proton, or x-ray source and as a platform for studying experimental fusion approaches, while also presenting more ambitious possibilities such as aneutronic power generation and propulsion applications. At the same time, it makes clear that the concept remained far from practical fusion power, with experimental devices operating several orders of magnitude below breakeven and with major unresolved issues involving confinement, losses, grid damage, and scale-up. Overall, the document treats IEC as a technically interesting but still highly speculative path toward fusion energy, while suggesting that its more limited spin-off applications were more plausible in the near term than its long-range power generation or propulsion applications.
UNCLASSIFIED/ /P"Olt OP"P"lelAL tt!I!! er•tY of various loss channels such as hitting the grid, charge exchange, or up-scattering in energy, the ions would be prematurely trapped in the potential well until they fused. The conventional requirement for fusion confinement is given in terms of the confinement parameter, nt, where n = the ion density and t is the confinement time. Also the ion energy (or temperature T) must be in the 20 or more keV range assuming D-T fuel. For breakeven, J. Lawson developed his famous "criterion" nt = 1014 cm·3-sec at T > 15 keV for DT fusion. Here t = energy confinement time, sec; n = ion density, cm ·3 and T = ion "temperature" or average energy. The Lawson criterion is independent of the confinement method, but does depend on the fuel via the selection of cross sections in the derivation. Magnetic confinement is generally limited to n ~ 1014 cm· 3 by pressure balance. Then a confinement time • of~ 1 sec is required. For Inertia Confinement Fusion (ICF) or "laser fusion", compression of targets can achieve n N 1024 , so a confinement time of only 10-10 sec is need (corresponding to the disassembly time of the compressed target). (For a general review of energy breakeven requirement for D-T fusion and other fuels like D-3He and p- 118, the reader referred to: G. Miley, Fusion Energy Conversion, American Nuclear Society, La Grange, IL 1973). Now consider the IEC. In principle, the ions focused on the center of the IEC can achieve a density of n ~1016, giving a required confinement time of 10-2 sec for DT fusion breakeven. This time can be restated in terms of the number of ion recirculations in the IEC potential well by dividing the well diameter by the average velocity of the recirculating ion. In later cases discussed in this report, this number is typically quite large, usually N1000 recirculations. Achievement of this large number of recirculations requires strong reduction of all of the loss channels noted earlier. Grid losses can be reduced by STAR mode operation discussed later where the recirculating ions possess beam -like trajectories passing through the center of the grid opening. The ideal, however, is the elimination of the grid altogether which can be done via formation of virtual potential structures, originally proposed by Farnsworth and discussed in following sections. The temperature requirement also leads to a fundamental difference in the IEC physics vs. other confinement approaches. (Note that "temperature" is not a proper term here since it implies an equilibrium distribution while the IEC is far from that with its beam-like ions. Thus, the reader should view "temperature" as meaning average energy of the ions. In doing that, however, it is assumed that the ion energy distribution is known so that averaging is possible). Most ions in the IEC are born near the chamber wall so are accelerated to an energy close to the applied voltage on the grid during the extraction process. A reasonable estimate is that the ions reaching the fusion region in the center have an energy near 80 percent of the grid voltage on average. Thus it becomes relatively easy to achieve the Lawson D-T requirement by applying a voltage of~ 25 kV. In fact most IEC neutron sources discussed later operate at voltages > 80 kV to get into an energy range giving a higher fusion cross section. In sharp contrast, magnetic fusion devices struggle to obtain a temperature in the 10 keV range since the entire plasma population must be heated (vs. direct ion acceler ation in the IEC) due to the equilibrium distribution maintained in these plasmas. Another very important point is that Lawson assumed that the ions and electrons were in thermal equilibrium, at the same temperature, T. This is a reasonable approximation for magnetic confinement, but not so for the IEC. In the latter, the electrons form a "distorted" Maxwellian distribution at an effective temperature well below that of the UNCLASSIFIED/ /FOR &FFICI0~ 1155 AN! X 2
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 72 pages are in the text index: search them above, or from the library's search.