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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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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.