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.

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“BEAMS”43 pages

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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region is essential to decrease the center potential and consequently allow incoming
beam ions to penetrate into the core region. In the DaIEC, it is possible to assist this
effect by an external control of the centerline potential by applying a bias voltage to the
dipole coil. In the UIUC experiment this was done by applying a voltage to a small
copper ring inserted in the core of the dipole magnet. The increase in the electron
density with a small center line bias applied was about 30 percent while the applied
voltage to the dipole structure was ~3 percent of the discharge voltage. The present
setup prevented the use of larger applied voltages which could further improve
neutralization, but these results still demonstrate the basic concept of dipole focusing
with coil bias control.
Figure 3.6 shows how the electron density changes with increasing magnetic field
measured at various coil biases in the current experiment. It is found that electron
density increases about 17 times more than that of non-magnetic field measurement.
So far, this increase is very close to our theoretical estimations.
Electron density vs B-field 25mTorr
I.00E+0S
0 100 200 300 400 500 600 700 800
B-field strength (Gauss) I--- Ground -+- Vc=-lOOV ----r- Vc=+IOOV I
Figure 3.6. Electron Density vs. Dipole Magnet Field Strength at 25mTorr, 20mA
The next section turns to some very interesting diagnostic studies of IEC devices,
including a jet thruster configuration, done by Joe Khachan's group at the University of
Sydney, Australia.
KHACHAN'S STUDIES AT U OF SYDNEY
Joe Khachan's IEC research at the University of Sydney has stressed studies of optical
emission spectroscopy of gridded IEC devices (Reference 3.11, 3.12). Using Doppler
spectroscopy of the Hydrogen Ha line they have shown that the micro-channels in an
IEC discharge operating in the units at tens of mTorr pressure range (for voltages less
than 30 kV) are mostly composed of molecular ions with approximately 20 percent
atomic hydrogen. They have also developed a spectroscopic model based on collisional
radioactive modeling to spectroscopically measure ion densities, electron energies and
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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.