Defense Intelligence Reference Document Inertial Electrostatic Confinement Fusion

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IEC BASICS
We begin by presenting the early very basic theoretical study by Elmore, Tuck, and
Watson (Reference 1.1). That addresses the key question of the fusion power density
obtainable with potential well confinement. One of their basic assumptions is that the
potential well is "dug" by electrons which trap ions. Certain added assumptions lead to
well depth, etc, and finally they conclude that the system is unstable for ion densities
sufficiently high that appreciable thermonuclear yield is expected. They qualify this
conclusion saying "admittedly, a more thorough investigation is required to obtain a
complete understanding of stability of this electrostatic device".
This result was quite negative for electron formation of potential wells, but left the
route possibly open since the subject "needed a more thorough investigation." Later,
for various reasons, R. W. Bussard still pursued this concept by introducing the High-
Energy Power Source (HEPS) Polywell device which uses a spherical simulated magnetic
field to stabilize the potential well formed by electrons. This represents a "hybrid"
magnetic-IEC confinement system where electrons are confined by the magnetic fields,
forming the potential well which "traps" ions. Apparently, Bussard's view was that this
added magnetic stabilization would overcome the earlier Elmore and Tuck criticism.
Subsequently, some of his reports used particle-in-cell simulations to support the view
that such a stabilized electron potential well would allow adequate density for attractive
fusion densities.
However, the next IEC experiments following the Elmore et al. analysis (prior to
Bussard's) were the Hirsch-Farnsworth experiments (Reference 1.2) which used ion (vs.
electron) injected traps (as does the present author's work). This selection was largely
driven by the desire to gain added stability by the large momentum of recirculating ions
that form the potential well. More about ion vs. electron injection routes will be covered
in later sections. Next, it is important to review the multiple well (''poissors" solution)
Farnsworth-Hirsch found for ion injected formation of potential wells in spherical
geometry. This is described in the paper by Hirsch (Reference 1.2). As seen from Figure
1.2, monoenergetic ions with angular momentum "drag in" electrons to create "onion
skin" like nested potential wells around the center of the sphere such that the ion
density goes to infinity in zero volume at the origin.
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