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Defense Intelligence Reference Document Inertial Electrostatic Confinement Fusion

Defense Intelligence Agency · 72 pages · text from the file's own layer

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.

  • p. 8 …hence a good probability of fusing before being lost from the fusion reaction chamber. In the…
  • p. 11 …If it can, the device would be simpler and smaller than a Tokamak, making it an…
  • p. 14 …However, they showed that grid deformation could be very harmful. This deserves several comments. First, the…
  • p. 15 …Again, this issue will be addressed further later. While earlier workers sought small grid openings designed…
  • p. 17 …More insights will be provided throughout this report, but the reader is encouraged to study the…
  • p. 19 …Upscattering out of the well must be minimized while electron 12 UNCLASSIFIED//EOAt OFFIQI.«1k 11181…
  • p. 29 …It operates by convergence of ions created between the grid and wall onto a small volume…
  • p. 30 …Such thrusters, however, do not scale well to lower powers for small satellites, nor are exhaust…
  • p. 33 …first, the channel grid will be separately hinged with a small servo motor such that its…
  • p. 35 …Thus, the mass of the IEC jet thruster system can potentially be reduced compared to a…
  • p. 43 …More insight into this can be obtained from the distribution functions for trapped ions, sketched in…
  • p. 44 …The source to sink issue noted several times here can be explained as follows. Two opposite…
  • p. 47 …However, since the fusion core radius in these calculations is very small on the order of…
  • p. 49 …instability in finite spherical systems may be excited for small beam velocities compared to those of…
  • p. 50 …However, an experimental study should be performed to verify this result. RIDER - ENERGY BALANCE STUDY Todd…
  • p. 53 …In addition, since both D-D and D- 3He reactions can be used for proton production…
  • p. 54 …This can be viewed as a small scale soft source for individual laboratory studies such as…
  • p. 55 …The 14.1-MeV neutrons from the D-T reaction will be the primary source for…
  • p. 59 …Due to their small size, they can be used in a large array along with TOF…
  • p. 65 …If vis large compared to v11, the effective scattering angle will be large, resulting in retrapping…
  • p. 67 …Fortunately, the IEC can be scaled up in energy gain while keeping a small size since…
  • p. 68 …The small size of the IEC is a key characteristic. If rapid development is to be…
  • p. 71 …In other words, this could also be thought of as a Q=100 DT equivalent breakeven…
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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
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Report, from the dia collection. The PDF is mirrored here; the original link is under it. 72 pages are in the text index: search them above, or from the library's search.