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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. 5 …Photo of Center Spot Formation ......................................................... 12 Figure 2.1. The "Historic" Early IEC Ion Injection Experiment…
  • p. 9 …The ideal, however, is the elimination of the grid altogether which can be done via formation…
  • p. 12 …This result was quite negative for electron formation of potential wells, but left the route possibly…
  • p. 14 …most critical factors which inhibit deep well formation are inadequate spherical focusing and charge neutralization. The…
  • p. 18 …The ion formation is done in the high pressure gun discharge region outside of the chamber…
  • p. 19 …Photo of Center Spot Formation. The main beam observed is a direct path along the injector…
  • p. 20 …Klevans, "Theory of Potential-Well Formation in an Electrostatic Confinement Device", J. of Appl. Phys., Vol…
  • p. 22 …As shown in the paper, he found structure for both consistent with well formation. One possible…
  • p. 30 …However, to date, formation of the jet has only been studied under steady-state operation. 23…
  • p. 31 …The result is the formation of the intense space charge neutralized ion beam (or "plasma jet…
  • p. 32 …This type of ion formation in the IEC has been studied extensively by workers at Nambe…
  • p. 35 …The approach being pursued at UIUC is the formation of deep potential wells with angular ion…
  • p. 45 …considered well formation with emphasis on angular momentum effects (Reference 4.4). Earlier studies had assumed…
  • p. 48 …is very encouraging for formation of deep wells in IEC devices designed for reactors using beam…
  • p. 49 …Krylov algorithm that does not require actual formation and storage of the Jacobian matrix to minimize…
  • p. 69 …While very demanding, plasma simulations show that carefully controlled injection can provide the potential well formation…
  • p. 70 …This eliminates the need for a grid by formation of a deep potential well (ion trap…
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events take place. Accordingly, he predicted that the Q-value (defined the ratio of
fusion power out to ion input power) of an IEC device operating with a 50/50 percent
deuterium-tritium (D-T) mixture would be ~0.21 for a 50-kV square well. This
conclusion would rule out the possibility of a fusion reactor, but would leave open the
development of driven neutron sources. However, this analysis contains several
questionable assumptions. For example, a tightly focused monoenergetic ion beam is in
fact a pessimistic scenario, because different co-moving ion species (such as D and T
with the same energy) result in a finite speed difference, thus fostering ion-ion
collisions and the degradation of the ion distribution function. It would be more realistic
to consider that, in a square well, friction between species would homogenize the speed
within the ion beam a~er some time, making the speed difference infinitesimal. This
line of argument was pursued earlier by Barnes et al., (Reference 4.3) who found Q ~
1. 3 for the same system.
ION INJECTION PORT
Ion extraction grid
Ion divertor
Pseudo-spherical
well for ion confinement
a
Electron divertor
I
E=Emax
E=Eo
Anode wall (ground)
Figure 4.2. Detail of the Anode and the Ion Injection Port in PFX-I (not to scale). Ion
and electron divertors are indicated, as well as the Eo and Ern" equipotential lines that define the
ion confinement region. The Eo contour line determines the region of absolute ion confinement.
In Chacon's work, a bounce-averaged Fokker-Planck (BAFP) model was employed to
obtain steady-state solutions for the ion distribution function and to calculate associated
fusion energy gains (Q-values) in a variety of operating conditions. These is done in
terms of source and sink strengths, ion injection energies, well depths, and electrostatic
potential shapes. Thus, the limiting assumptions by Nevins- namely that ions are
confined in a square potential well, and that their distribution is tightly focused and
monoenergetic, are relaxed. When these restrictive assumptions are removed, it is
found that large energy gains (Qs of hundreds) for beam-like solutions in square wells
35
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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.