Reply To: scaleablity of a reactor?
The Front Lens
The purpose of the front lens is to minimize the dispersion of the radiation beam and bring its focus to a sharp point. To accomplish this, a defection lens will be used.
Diffraction lenses use the interference between the periodic nature of EMF radiation and a periodic structure such as the matter in a crystal. An elementary derivation of the Bragg condition assumes that the incident waves are reflected by the parallel planes of the atoms in the crystal. There is constructive interference if the optical path difference between neighboring paths is a multiple of the wavelength.
Based on the energy wave length produced by the plasmoid, either Bragg- or Laue geometry will be used.
Bragg- vs. Laue geometry: The Bragg condition implies that higher incoming photon energies require smaller Bragg angles. At gamma-ray energies, Bragg angles are generally less than one degree. The reflection can be at the surface (so-called Bragg geometry) or the beam can pass through the crystal volume (so-called Laue geometry). The maximum efficiency for diffraction in the Bragg geometry is close to 100% (assuming no absorption).
A hard-X ray lenses operating in Bragg geometry using mosaic pyrolithic graphite crystals has been proposed by Frontera et al 1995.The concentrator consists of 28 confocal parabolic mirrors. Each mirror is made up of small pieces of mosaic crystal with the diffraction planes parallel to the parabolic surface, which results in a broadband energy response.
Laue geometry lenses : In a crystal diffraction lens, crystals are usually disposed on concentric rings such that they will diffract the incident radiation of the same energy onto a common focal spot. A crystal at a distance r1 from the optical axis is oriented so that the angle between the incident beam and the crystalline planes is the Bragg angle. Its rotation of around the optical axis results in concentric rings of crystals. With the same crystalline plane used over the entire ring, the diffracted narrow energy band is centered on E1.
Two subclasses of crystal diffraction lenses can now be identified – narrow bandpass Laue lenses and broad bandpass Laue lenses.
Narrow bandpass Laue lenses use a different crystalline plane for every ring in order to diffract photons in only one energy band centered on an energy E1=E2 (see figure).
Overall General Reactor Design.
All alpha ions and fast electrons from the polls of the plasmoid are converted to x-rays through tungsten target irradiation.
256 x-ray production modules are evenly space on the surface of a sphere of N meters in radius each centered on the common module focal point at the center of the sphere.
This large N meters in radius sphere holds a vacuum and but at its center, a boron/hydrogen gas is puff released.
In a fusion application, boron/hydrogen fusion at the center of the large sphere produces X-rays that are directly converted to electricity on the inner surface of the sphere by a foil based X-ray to electricity conversion layer.
All Xcon modules are fired simultaneously. Because fusion is used to produce x-rays in the module, a power gain based on its fusion energy gain factor “Q” of the module can be expected.
By comparison, a Q factor of only 1% will put Xcon and the LIFE laser based reactor on an even footing, since the efficiency of its lasers is only 1%.
The design risk to improve the performance characteristics of the Xcon over existing ICF concepts is small.
Pulsed Operation
Unlike the Z-machine, whose firing repitition rate is at best .1/sec and life at 10/sec, the Xcon is capable of a firing repetition rate of 1000/sec.
Applications
With some design reconfiguration the Xcon concept is capable of the following functions:
Design replacement for the Z machine
Design replacement for the LIFE reactor
A new ICF design concept
Fusion based nuclear rocket engine.
An Xcon based in Space star wars X-ray type anti-ballistic missile system
If miniaturized, a stage one trigger for a pure fusion nuclear weapon.
Development Funding
This type “out-of-the-box” system is desirable for development by DARPA since it involves possible improvement to existing and future fusion concepts and weapons.