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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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There are several advantages of the dipole-assisted IEC. By applying the desired
voltage to the cathode grid, high-energy ions are easily obtained, hence plasma heating
is straightforward. Indeed in this case fusion is dominated by beam-beam (non-
Maxwellian reactions). Also, the dipole magnet at the center of the device produces
field lines that trap ions and compresses them within the inner radius of the dipole.
Thus, a very high ion density can be achieved leading to high reaction rates via beam-
beam fusion. Biasing the dipole magnet to the same potential as the cathode grid
solves the problem of space charge build-up due to the high ion density at the center of
Da!EC.
DAIEC EXPERIMENTS
The purpose of current experiments is to investigate the focusing effect of a dipole
magnetic field in a spherical IEC. In particular, the primary goal is to measure the
increase in plasma densities achieved by a dipole-assisted IEC. In theory, the
introduction of a current ring or dipole coil into the base configuration would focus
particles into the center of the dipole, increasing the plasma density at the core of the
device. A schematic of the current experimental setup is shown in Figure 3.5.
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Figure 3.5. (a} Dipole Magnetic Field and (b} Layout of Devices
This experiment employs two split spherical grids as shown in Figure 3.5. Ions are
created in the discharge between these grids and the vessel wall. They are extracted
and accelerated by the grid potential so they pass through the dipole field of Figure
3.Sa. Experiments have confirmed that an order of magnitude density increase (vs. no
dipole present) can be achieved in the center region. A double Langmuir probe is
inserted at various positions throughout the center region.
The use of a bias on the dipole magnet structure to control space charge build-up was
also studied. In an ion-injected IEC partial space-charge neutralization at the core
30
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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.