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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 …Photo of Center Spot Formation ......................................................... 12 Figure 2.1. The "Historic" Early IEC Ion Injection Experiment…
  • p. 9 …The ideal, however, is the elimination of the grid altogether which can be done via formation…
  • p. 12 …This result was quite negative for electron formation of potential wells, but left the route possibly…
  • p. 14 …most critical factors which inhibit deep well formation are inadequate spherical focusing and charge neutralization. The…
  • p. 18 …The ion formation is done in the high pressure gun discharge region outside of the chamber…
  • p. 19 …Photo of Center Spot Formation. The main beam observed is a direct path along the injector…
  • p. 20 …Klevans, "Theory of Potential-Well Formation in an Electrostatic Confinement Device", J. of Appl. Phys., Vol…
  • p. 22 …As shown in the paper, he found structure for both consistent with well formation. One possible…
  • p. 30 …However, to date, formation of the jet has only been studied under steady-state operation. 23…
  • p. 31 …The result is the formation of the intense space charge neutralized ion beam (or "plasma jet…
  • p. 32 …This type of ion formation in the IEC has been studied extensively by workers at Nambe…
  • p. 35 …The approach being pursued at UIUC is the formation of deep potential wells with angular ion…
  • p. 45 …considered well formation with emphasis on angular momentum effects (Reference 4.4). Earlier studies had assumed…
  • p. 48 …is very encouraging for formation of deep wells in IEC devices designed for reactors using beam…
  • p. 49 …Krylov algorithm that does not require actual formation and storage of the Jacobian matrix to minimize…
  • p. 69 …While very demanding, plasma simulations show that carefully controlled injection can provide the potential well formation…
  • p. 70 …This eliminates the need for a grid by formation of a deep potential well (ion trap…
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Table 3.1. Estimated Performance Parameters or the IEC Ion Thruster
Parameter IEC Ion Thruster
Propellant Xenon
Molecular Weight ( amu) 131.3
Specific Impulse (s) 3000
Thrust (mN) 34
Jet Power (W) 500
Net accelerating Potential (V) 600
Beam Current (mA) 832
Power Loss to Grid (W) <50
Power Loss to Bresstrahlung < I
Radiation (W)
Power loss to Ionization of 200-250
Propellant (W)
Input Power (W) 750-800
Thruster Efficiency (%) 62-68
In summary, the power efficiency of the IEC thruster appears to be competitive to
existing ion thrusters. What are the advantages then? These were outlined earlier and
include a more compact design, large heat rejection area, an exhaust jet closer to
quasi-neutrality, reduced neutral propellant leakage, and reduced grid erosion. Thus,
the mass of the IEC jet thruster system can potentially be reduced compared to a high-
power Hall-type thruster and also its lifetime can be increased significantly. In this
overall context, then, the IEC thruster potentially offers an important improvement in
performance for high power thruster applications.
Scale-up to p- 11B IEC Space Power Unit/Thruster
The electrically driven IEC jet thruster provides an important data base for a next step
p- 11B IEC jet thruster. Jumping to p- 11 B for this application may appear overly
ambitious. However, neutron less fusion seems essential in a small space thruster to
avoid excessive weight from shielding of electronics. Considerable experience with
fusing plasmas in IECs has been gained through development of IEC DD neutron
sources. These devices operate with ~ 80- keV D-ion beams using the non-Maxwellian
character of the IEC. This important characteristic makes use of p- 11B a realistic goal.
In fact, operation with circulating ion energies at the desired 150 keV energy for p- 11 B
has already been achieved at the UIUC and several other laboratories working on IECs.
The issue then is how to achieve adequate confinement times. The approach being
pursued at UIUC is the formation of deep potential wells with angular ion injection using
a differentially-pumped RF ion gun, as discussed in later sections. A proposed
experiment to demonstrate p- 11 B physics is discussed in Section VI.
In summary, the extraction of a jet plasma from a gridded IEC opens the way to a
number of added plasma applications for the IEC. This present discussion is intended to
identify an orderly progress of IEC applications in commercial space power, starting
with an electrically driven IEC thruster to a self-powered IEC p- 11 B unit. The attractive
characteristics of the electrically driven device, namely light weight, low maintenance,
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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.