“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…
UNCLASSIFIED//509 QFFI~llk WEE e•lklf
predict fusion rates. This latter achievement makes spectroscopic measurements
simpler to carry out since hydrogen can be used to predict these fusion rates, which
excludes the radiation hazard in a laboratory situation where shielding is not possible.
In follow-on work, they simplified the modeling of charge exchange with an analytical
approach to charge exchange modeling based on Markov chain theory.
Table 4.1. Comparison of Analytical and Numerical Estimates of Q-values in
a beam-Dominated Solution -- for a SO-kV Square Well.
Analytical BAFP
(Chacon)
With co-moving ions Q ~ 0.21 - Ref. 4.1, Nevins -
Without co-moving ions Q ~ 1.3 - Ref. 4.2, Chacon Q~ 1
The movement of neutrals moving away from the cathode seen from the spectroscopic
measurements was also confirmed by carrying out a dusty plasma measurement to
show charged micron sized insulating spheres (dust) experience a force away from the
cathode centre (Reference 3.13). The explanation of this was attributed to a local
potential maximum established at the center of the cathode, which accelerates ions at
that point away from the center. Due to charge exchange, ions become neutrals and
are able to leave along the microchannels out to the anode. The ion drag force on the
dust moved the dust particles away from the center. Based on this observation,
Khachan has engineered the collimated beam of exiting neutrals from the cathode to
make a simple electric propulsion thruster where a unidirectional micro-channel
emerges from a conical cathode (Reference 3.14). He claims that the specific impulse of
the thruster and its efficiency greatly exceed existing electric propulsion thrusters. Note
that this concept, while having some similarities, differs in some details from Miley's jet
thrusts describe earlier.
CONCLUDING REMARKS
The primary focus of this section has been on two key alternate geometries: The
cylindrical and jet IECs. Both provide unique capabilities for applications using IEC
sources and IEC space thruster, respectively. These uses, however, require competition
in commercial markets with other options. This IEC technology is just now emerging, so
its success in commercialization has yet to be established. More about such applications
is discussed in Section V.
In conclusion, the DaIEC is a very interesting alternate IEC configuration. However, it
has received little experimental study to date, so much more needs to be done to fully
evaluate its potential.
REFERENCES
3.1 B. Bromley, L. Chacon, and G. Miley, "Approximate Modeling of Cylindrical Inertial
Electrostatic Confinement, (IEC) Fusion Neutron Generator," Proc. 16th International
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