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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 …Sketch of Two Opposite Limits of the Beam·Maxwellian Equilibrium .. 38 Figure 4.5. The Definition…
  • p. 6 …Comparison of Analytical and Numerical Estimates of Q-Values in a Beam-Dominated Solution -- for a…
  • p. 8 …shows the "Star Mode" discharge where ion beams are created that pass through the grid openings…
  • p. 9 …discussed later where the recirculating ions possess beam-like trajectories passing through the center of the…
  • p. 10 UNCLASSIFIED/ ;raA 8FFIIItliL ~81!! SHL'f beam-like ions. Since electron energy loss processes such as…
  • p. 11 …In addition, its beam-like reactions (highly non-Maxwellian) make the IEC very well suited for…
  • p. 13 …a beam created at the anode and accelerated by the applied cathode voltage; a low-energy…
  • p. 14 …Good convergence is required to achieve optimal beam-beam reactivity scaling for the application that require…
  • p. 15 …The observed loss of convergence with decreasing pressure and increasing current makes achieving significant beam-beam…
  • p. 16 …For a power reactor the objective is to obtain ion beam-beam collisions in this central…
  • p. 17 …the "conventional" beam-like one. A key issue for this concept is how much plasma compression…
  • p. 19 …The main beam observed is a direct path along the injector angle. Other faint light channels…
  • p. 21 …Note that six ion "guns" were used to create a low energy ion beam that entered…
  • p. 22 UNCLASSIFIED/;SflHl 8FFIIItliL ~81!! 8HL'I' was obtained from recirculation beam-beam reactions in a potential…
  • p. 23 …The key physics point is that the beam-beam fusion rate scales as the ion current…
  • p. 26 …Scoping calculations of beam-background fusion rates predict that a 3 He- 3 He reaction product…
  • p. 27 …of the ion density squared scaling for beam-beam reactions. REFERENCES 2.1 R. L. Hirsch…
  • p. 28 …As such, the beam convergence (compression) is limited to lower values, hence lower core densities (an…
  • p. 30 …by the intersection of the multiple ion beams, serves to deflect ions into the escaping jet…
  • p. 31 …The result is the formation of the intense space charge neutralized ion beam (or "plasma jet…
  • p. 32 …in the symmetric microchannels into a directed beam or jet. Comparison to a Conventional "Plasma" Thruster…
  • p. 33 …The ion beams finally exit through an opening in the ground sphere of the IEC device…
  • p. 35 …These devices operate with ~ 80- keV D-ion beams using the non-Maxwellian character of the…
  • p. 36 …Two ion sources inject 40-keV deuterium and helium-3 ion beams toward the center of…
  • p. 37 …Indeed in this case fusion is dominated by beam-beam (non- Maxwellian reactions). Also, the dipole…
  • p. 38 …the center potential and consequently allow incoming beam ions to penetrate into the core region. In…
  • p. 39 …Comparison of Analytical and Numerical Estimates of Q-values in a beam-Dominated Solution -- for a…
  • p. 40 …Hora, "Converging Beam Neutron Source for Driving a Sub-critical Fission Reactor", Proceedings, ICONE 8, CD…
  • p. 41 …Namely, the time scale for collisional degradation of the beam-like ion distribution function is crucial…
  • p. 42 …For example, a tightly focused monoenergetic ion beam is in fact a pessimistic scenario, because different…
  • p. 44 …Thus, weak sinks and strong sources will result in a large beam population, increasing the beam…
  • p. 45 …Sketch of Two Opposite Limits of the Beam-Maxwellian Equilibrium. The solid line corresponds to a…
  • p. 46 …injected beam current, average injection energy, energy spread associated with the velocity component in both parallel…
  • p. 47 …As stated in Section I, the current scaling for beam-beam reactions is strictly 12. However…
  • p. 48 …is very encouraging for formation of deep wells in IEC devices designed for reactors using beam…
  • p. 49 …To do this, it is assumed that the electrostatic confinement equilibrium ion beams are proportional to…
  • p. 50 …When an ion beam is hot, the waves excited by the instability are ion acoustic type…
  • p. 51 …Rider was particularly interested in the claim that due to its beam-like non- Maxwellian plasma…
  • p. 52 …Diagram Showing Equipotential Surfaces of the IEC Cathode Grid and Their Focusing Effect on a Beam…
  • p. 59 …of detectors, the detector configuration, the collimated beam size, the acquisition time, and other scan-related…
  • p. 63 …Alternately, for space propulsion, the proton beam, augmented by injection of heavy atoms to increase the…
  • p. 68 …Due to its inherent non-Maxwellian (beam-like) plasma, the IEC is especially well suited for…
  • p. 70 …This configuration is highly non-Maxwellian due to the beam dominated nature of the trapped ions…
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Bussard HEPS (or Polywell) Concept
In Bussard's Polywell IEC, a spherical magnetic field termed a "Polywell" is
approximately obtained with a multi-pole cusp magnetic field (Reference 1.6). More
about the theory of flows in this configuration is given in the paper by N. Krall
(Reference 1.7), and some stability issues are addressed in the Wang and Krall paper of
Reference 1.8. One of the key physics revolves around electron losses from the poles in
the cusp field. Krall and Bussard argue that a plasma "waffle-ball" effect causes the loss
cone angle to be reduced due to the high pressure developed in the IEC plasma. The
issue still needs further experimental verification. The Polywell approach is very
important and it is currently pursued by R. Nebel's EMC2 company in Santa Fe with
significant DOD funding. More insights will be provided throughout this report, but the
reader is encouraged to study the reports/articles, as already explained earlier, since
the present report is directed more at "ion injected" type devices studies at UIUC.
Barnes Nebel Penning Trap
The Penning trap concept described in Reference 1.9 is explained by Barnes et al. as:
"The Penning Fusion (PF) device uses a unique plasma confinement principle. In PF, a
nonneutral electron plasma is confined in a modified Penning trap by a combination of
applied magnetostatic and electrostatic fields. The electron space charge, in turn,
electrostatically confines a minority, unmagnetized ion species. To apply such a system
to fusion energy production, it is necessary to raise the applied voltages (producing the
confining electrostatic field) to the order of 100 kV or greater. Even with such a high
potential, in a practically sized system, the electron density (and to a greater degree
the ion density) falls short of that required to give reasonable fusion reactivity. Thus,
intrinsic to PF being an interesting concept is the idea of ion focusing, either in space or
time, or some other means of enhancing ion reactivity. In this way the reactivity may
be greatly enhanced over that available with the background density. Penning Fusion is
strongly related to the IEC, but it attempts to address two limitations of the IEC. First,
following the Bussard-Krall Polywell theory (Reference 1.6, 1.7) the grid is replaced by
an electron cloud, which forms a virtual cathode. In this way, ion-grid collisions and
associated limitations (such as secondary electron emission from the grid and grid
heating) are avoided. Second, high rates of ion-ion collisions, which limit the
theoretically achievable fusion gain Q (fusion power/input power) to around unity are
avoided to some extent with this type of well. However, issues of electron loss and cone
losses, radiation damage of the magnets and cooling, and the ability to circumvent the
Elmore et al. density limit remain as questions.
Nebel POPS Device
Theoretical studies by Barnes and Nebel (Reference 1.10) show that a small internal
oscillating ion cloud may undergo a self-similar collapse in a harmonic oscillator
potential formed by a uniform electron background. This then forms a dynamic IEC
device, but with a quite different ion distribution factor vs. the "conventional" beam-like
one. A key issue for this concept is how much plasma compression can be achieved by
the POPS (Periodically Oscillating Plasma Sphere) oscillations. Recent work has shown
that by properly programming the distribution function of the injected electrons it is
possible to significantly improve the space dynamic charge neutralization and the
plasma compression. Reference 1.10 extends that previous work in a systematic
fashion by developing a formalism that determines the required velocity distribution of
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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.