“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/;SflHl 8FFHil.t.L l!j!ilE 8HLV
The basic principle of this detection method, shown in Figure 2.5, is common to most
NAA but is now specialized for detecting the basic elements in the land mines. Key
design considerations are the source strength required, the neutron energy desired (i.e.
D-D vs D-T fusion) and the type and location of neutron and x-ray detectors (from
Reference 2.7).
How to Detect Landmine
Neutron yield of ·- 102 1s required
y.ray
detector
=
neutron
ll>"l trc,11
,:apturt?d r y
-,.-ray
thermol
neutron
l,llldtnillf'
1:,:. X 1·• I(,.:. i·~·i:,)
':>IUll
H(n, n') • • • H SCclttr:•r IH·lltr,:,11
Figure 2.5. Scheme for Landmine Detection Using a Hybrid Magnetron Type IEC Neutron
Source (From Reference 2.7)
The IEC developed for this work used a magnetron ion generation technique to improve
the neutron production efficiency (Reference 2.6). A built-in magnetron discharge ion
source was installed in the IEC. With the magnetron discharge, ions are produced in the
vicinity of the vacuum chamber (anode) at negative electric potential. Therefore, the
ions produced are expected to have nearly full energy corresponding to the applied
voltage to the IEC cathode but slightly smaller energy than the anode potential. This
prevents them from hitting the anode of the opposite side improving both fusion
reaction rate and ion recirculation life. (Note that this approach is yet another way to
address the problem of preventing ions created externally from escaping after entering
the potential well. The technique here is to use the internal source to create the ions at
a potential level less than the height of the potential well).
In addition to an internal source, the magnetron can produce ample ion current to
maintain the discharge under low-pressure conditions. Ions generated in the ion source
are attracted by the IEC central cathode because of its high negative electric potential.
Therefore, the Kyoto investigators expected that a higher applied voltage would
increase the extraction current, giving a higher IEC cathode current. However, it was
18
UNCLASSIFIED/ ;CEiOAr OFFI&l1ltk WliEii &••LY