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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 …This is important for long run times since 10n bombardment of the grids, hence grid wire…
  • p. 9 …This time can be restated in terms of the number of ion recirculations in the IEC…
  • p. 15 …This work and others on the small gridded systems at that time showed several important problems…
  • p. 17 …interesting concept is the idea of ion focusing, either in space or time, or some other…
  • p. 18 …confinement time for aneutronic fusion. This assumes, however, very precise control is maintained over the energy…
  • p. 23 …By selecting the pulse width to match or exceed the ion confinement time, typically order of…
  • p. 27 …This is the approach used at the UIUC. However, introduction of the source into the configuration…
  • p. 30 …The second jet would serve the integration purpose of the platform without having to expend time…
  • p. 35 …The issue then is how to achieve adequate confinement times. The approach being pursued at UIUC…
  • p. 36 …step in a timely fashion, however. The Dipole Assisted IEC (DaIEC) The dipole assisted IEC DaIEC…
  • p. 38 …in the current experiment. It is found that electron density increases about 17 times more than…
  • p. 41 …Namely, the time scale for collisional degradation of the beam-like ion distribution function is crucial…
  • p. 42 …would homogenize the speed within the ion beam a~er some time, making the speed difference…
  • p. 43 …1) The electrostatic well is deep enough (Eo > 100 kV); 2) Ion confinement time is long…
  • p. 44 …The source to sink issue noted several times here can be explained as follows. Two opposite…
  • p. 49 …The time convergence test suggests that employing the largest time step compatible with accuracy in a…
  • p. 50 …When an ion beam is hot, the waves excited by the instability are ion acoustic type…
  • p. 51 …used an analytical model of charge- exchange collisions in the IEC plasma to include ion time…
  • p. 53 …Nevins, Can inertial electrostatic confinement work beyond the ion-ion collisional time scale?" Phys. Plasmas, Vol…
  • p. 54 …This method uses a pulsed high-energy neutron source and the time-of-flight (TOF) diagnostics…
  • p. 57 …The longer the charge time, the higher the charge in the energy storage capacitor bank and…
  • p. 58 …The challenge in these systems is that the unloading time is short and the container is…
  • p. 59 …by the number of detectors, the detector configuration, the collimated beam size, the acquisition time, and…
  • p. 62 …The Tokamak has a shorter trip time by employing a power level that is six times…
  • p. 63 …In this fashion, an array of multiple IECs increase the overall confinement time roughly in proportion…
  • p. 64 …This recirculation significantly increases the confinement time verses that of a simple cusp devise, leading to…
  • p. 65 …This re-trapping greatly increases the confinement time of a MCSA fusion device. 58 UNCLASSIFIED/;CEiOAt…
  • p. 66 …in the IEC high power-to-weight of the MCSA enables fast trip times. The concept…
  • p. 67 …across the outer surface, so increased confinement times have been achieved by going to the massively…
  • p. 68 …Here n is the ion density and Tis the ion confinement time. Assuming the converged core…
  • p. 69 …A specially designed radio frequency (RF) ion gun is installed on the side of the chamber…
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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.