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This Defense Intelligence Agency reference document, dated 10 March 2010, covers inertial electrostatic confinement (IEC) fusion. It was produced in FY 2009 under the DIA's Advanced Aerospace Weapon System Applications (AAWSA) program. The report focuses on work at the University of Illinois Urbana-Champaign and reviews IEC basics, experiments, theory and applications such as neutron sources, explosives detection and space propulsion. It concludes by proposing a breakeven experiment for p-11B fusion that uses a hydrogen plasma simulation.
UNCLASSIFIED//F8A 8FFHil.l1k 'JE'lii 811k¥ In this RF gun, a graded index magnetic field is used to increase the ionization efficiency. A key component is the magnetic focusing lens at the extraction port. This allows very efficient differential pumping between the high pressure gun chamber and the low pressure IEC chamber. It also provides some control of the angular velocity of entering ions. The UIUC RF ion-injector is shown attached to an IEC chamber in Figure 1.6, and a photograph of the focal spot achieved with injection from this single injector is shown in Figure 1.7. Note that ion scattering off of the center dense plasma "core" causes noticeable (but "faint") recirculating ion beams observed in the photograph of the discharge. With additional injectors, the recirculation pattern should become quite symmetrical about the center. These studies did include differential pumping so that number of recirculating passes, ~, by an ion was very low, roughly 2. The injected ion current, I, was about SO mA. Still, based on measurements of neutrons emitted using deuterium fuel, the Q (fusion energy gain/energy in) was remarkable for such a small device, order of 10-6 . Based on these results, an aggressive p- 11 B breakeven experiment using this type of IEC is discussed in Section VI. Figure 1.6. RF Gun Attached to an IEC Chamber in the UIUC Laboratory CLOSING REMARKS Figure 1.7. Photo of Center Spot Formation. The main beam observed is a direct path along the injector angle. Other faint light channels indicate beams for scattering of the central core region. As seen, a wealth of information has been developed in studies of gridded IEC devices. However, the beam-background fusion used in these devices involves important differences in physics compared to what is needed for future beam-beam IEC reactors. Most notable is the need to maintain an extremely low background pressure to prevent interactions with background neutrals. Further, physical grids are subject to damage at high power levels. As pointed out, some studies show grids can survive at modest powers. But, for aggressive power units such as the p- 11 B plant of Section VI, they must be replaced with virtual electrode surfaces creating a deep potential well for ion confinement. Upscattering out of the well must be minimized while electron 12 UNCLASSIFIED//EOAt OFFIQI.«1k 11181! 8HLV
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Report, from the dia 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.