High-energy plasma generator using radio-frequency and neutral beam power
An apparatus for generating a highly energetic plasma employs a low-energy neutral beam injected into a magnetically contained mirror plasma to produce plasma ions boosted in energy to fusion levels by a coordinated radiofrequency field.
1. An apparatus for producing high-energy plasma comprising:
a magnetic mirror containment field providing axially-extending magnetic flux lines converging at opposed first and second ends of a containment volume holding a plasma;
a neutral beam generator directing a neutral beam of particles into the containment volume at a predetermined pitch and energy so that the particles disassociate into plasma ions within the containment volume, and
a radiofrequency generator producing an electrical field to accelerate the plasma ions to an energy sufficient for fusion of the plasma ions.
2. The apparatus of claim 1 wherein the frequency of the electrical field is functionally dependent on a cyclotron frequency at turning points for the plasma ions of the neutral beam in the magnetic mirror containment field.
3. The apparatus of claim 2 wherein the frequency is a harmonic of the cyclotron frequency greater than the cyclotron frequency.
4. The apparatus of claim 1 wherein the energy of the neutral beam is set so that more than 50 percent of the neutral beam particles are converted to plasma ions.
5. The apparatus of claim 1 wherein the neutral beam has an energy of less than 50,000 electron volts.
6. The apparatus of claim 1 wherein the radiofrequency generator boosts the energy of the plasma ions from the neutral beam by more than 2 times.
7. The apparatus of claim 1 wherein the radiofrequency generator includes an antenna positioned to be proximate to a reflection limit of the plasma ions and to generate a rotating electric vector perpendicular to the axis of the magnetic mirror containment field.
8. The apparatus of claim 7 wherein the pitch is between 300 and 60° to the axis.
9. The apparatus of claim 1 further including a treatment volume at least partially surrounding the containment volume to receive high-energy neutrons therethrough and containing an element for transmutation into a different element.
10. The apparatus of claim 9 wherein the element for transmutation is a precursor to a a medical radioisotope selected from the group consisting of precursors 99 Mo, 131 I, 133 Xe; and 177 Lu.
11. The apparatus of claim 9 wherein the element for transmutation is an exhausted nuclear fuel.
12. The apparatus of claim 1 wherein the neutral beam is selected from the group consisting of deuterium and tritium.
13. The apparatus of claim 1 wherein the neutral beam is deuterium.
14. The apparatus of claim 1 wherein including a pair of magnetic coils producing the magnetic mirror containment field and wherein the radiofrequency generator provides an antenna between the magnetic coils and wherein the containment volume is contained within a gas-tight chamber.
15. A fusion apparatus comprising:
a reaction volume holding a fusible material within a first axially-extending magnetic containment field;
a first and second plasma plug flanking the reaction volume along the axis; each plasma plug including:
(a) a magnetic mirror containment field providing axially-extending magnetic flux lines converging at opposed first and second ends of a containment volume holding a plasma;
(b) a neutral beam generator directing a neutral beam of particles into the containment volume at a predetermined pitch and energy so that the particles disassociate into plasma ions within the containment volume; and
(c) a radiofrequency generator producing an electrical field to accelerate the plasma ions to an energy above that of the particles entering the containment volume;
whereby plasma ions escaping from the first and second plasma plug produce a fusion reaction in the reaction volume.
16. The fusion apparatus of claim 15 wherein a pressure of plasma ions within the first and second plasma plug is greater than a pressure of plasma ions within the reaction volume.
17. The fusion apparatus of claim 16 further including an electrical generator receiving neutrons from the reaction volume to generate electrical power.