System of converging plasma pistons

Patent metadata

Field	Value
Publication number	US-11744002-B2
Application number	US-201816645066-A
Country	US
Kind code	B2
Filing date	Sep 11, 2018
Priority date	Sep 12, 2017
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

A magnetic confinement system includes a magnetic mirror device that includes a chamber to hold a target plasma and a coil arrangement to generate a magnetic field configuration in the chamber to confine the target plasma in cylindrically-symmetric form in the chamber, the magnetic field configuration having open ends. The magnetic confinement system further includes plasma guns to generate plasma pistons and project the plasma pistons at the open ends of the magnetic field configuration. In operation, the plasma pistons converge towards each other to close the open ends of the magnetic field configuration and to compress and heat the target plasma.

First claim

What is claimed is:

1. A magnetic confinement system comprising:
a) a magnetic mirror device including
i) a chamber to hold a target plasma;
ii) a coil arrangement to generate a magnetic field configuration in the chamber to confine the target plasma in cylindrically-symmetric form in the chamber, the magnetic field configuration having open ends, the coil arrangement including plural coils arranged along a length of the chamber to generate a longitudinal magnetic field to confine the target plasma radially, the magnetic field strengthened at the ends of the magnetic field configuration to form magnetic mirrors; and

b) plasma guns to generate plasma pistons and project the plasma pistons at the open ends of the magnetic field configuration and at the target plasma confined by the magnetic field configuration, the plasma guns arranged to project the plasma pistons along a longitudinal axis of the chamber, the plasma pistons in operation converging towards each other, current through the coils of the coil arrangement in operation being adjusted as the converging plasma pistons enter the chamber, the coils including end coils at ends of the target plasma and central coils between the end coils, wherein the current being adjusted includes relaxing current in the end coils to relax the magnetic mirrors so as to accommodate the converging plasma pistons, and wherein the system is configured to electromagnetically pin the plasma pistons in place at the target plasma, to plug the open ends of the magnetic field configuration and to compress and heat the target plasma.

2. The system of claim 1 , wherein the chamber is cylindrical.

3. The system of claim 1 , wherein each of the plasma guns is configured to project one of the plasma pistons at one of the open ends of the magnetic field configuration.

4. The system of claim 1 , wherein the plasma guns are linear railguns and the chamber is non-cylindrical to accommodate the linear railguns.

5. The system of claim 1 , wherein the plasma guns are coaxial railguns.

6. The system of claim 1 , wherein each plasma piston comprises a series of plasma pistons.

7. The system of claim 1 , wherein each plasma piston comprises primarily a composition different from that of the target plasma.

8. The system of claim 1 , wherein each plasma piston comprises primarily thermonuclear fuel.

9. The system of claim 1 , further comprising means to hold the plasma pistons in position after compression of the target plasma.

10. The system of claim 1 , wherein the target plasma is confined in a field-reversed configuration.

11. The system of claim 1 , wherein the target plasma is a spheromak.

12. The system of claim 1 , wherein the coil arrangement is configured to modify the magnetic field configuration progressively to maintain compression of, or further compress, the target plasma via the plasma pistons.

13. The system of claim 1 , the plasma pistons are electromagnetically pinned in place at the target plasma by reversing current direction in the end coils while maintaining current direction in the central coils to provide cusp magnetic fields to pin the plasma pistons in place at the target plasma.

14. The system of claim 1 , wherein the plasma pistons are electromagnetically pinned in place at the target plasma by forcing current through the plasma pistons to provide a Lorentz force to hold the plasma pistons in place at the target plasma.

15. The system of claim 1 , further comprising a mechanism to further compress the target plasma radially.

16. The system of claim 15 , wherein the mechanism is configured to increase the magnetic field at a center region of the magnetic field configuration to compress the target plasma radially.

17. The system of claim 15 , wherein the mechanism includes a liner within the chamber, the liner configured to implode to compress the target plasma radially.

18. The system of claim 1 , wherein the target plasma comprises primarily thermonuclear fuel.

19. The system of claim 18 , wherein the target plasma further comprises a relatively small amount of heavy ions to cool electrons via bremsstrahlung.

20. The system of claim 1 , further comprising a central conductor extending through the chamber between two of the plasma guns to stabilize the plasma pistons.

21. The system of claim 20 , wherein the central conductor is configured to further stabilize the plasma pistons, the target plasma, or both, by application of a current through the central conductor.

22. A magnetic confinement system comprising:
a) a magnetic mirror device including
i) a chamber to hold a target plasma;
ii) a coil arrangement to generate a magnetic field configuration in the chamber to confine the target plasma in cylindrically-symmetric form in the chamber, the magnetic field configuration having open ends, the coil arrangement including plural coils arranged along a length of the chamber to generate a longitudinal magnetic field to confine the target plasma radially, the magnetic field strengthened at the ends of the magnetic field configuration to form magnetic mirrors;

b) coaxial railguns to generate plasma pistons and project the plasma pistons along a longitudinal axis of the chamber at the open ends of the magnetic field configuration, the plasma pistons in operation converging towards each other, current through the coils of the coil arrangement in operation being adjusted as the converging plasma pistons enter the chamber, the coils including end coils at ends of the target plasma and central coils between the end coils, wherein the current being adjusted includes relaxing current in the end coils to relax the magnetic mirrors so as to accommodate the converging plasma pistons, and wherein the system is configured to electromagnetically pin the plasma pistons in place at the target plasma, to plug the open ends of the magnetic field configuration and to compress and heat the target plasma;
c) a mechanism to further compress the target plasma radially; and
d) a central conductor extending through the chamber between two of the coaxial railguns to stabilize the plasma pistons.

23. The system of claim 22 , wherein each of the plasma pistons comprises primarily a composition different from that of the target plasma.

24. The system of claim 22 , wherein the mechanism to further compress the target plasma radially includes a liner within the chamber, the liner configured to implode to compress the target plasma radially.

25. The system of claim 22 , wherein the central conductor is joined at each end to a central electrode of one of the two coaxial railguns.

26. The system of claim 22 , wherein the plasma pistons are electromagnetically pinned in place at the target plasma by reversing current direction in the end coils while maintaining current direction in the central coils to provide cusp magnetic fields to pin the plasma pistons in place at the target plasma.

27. The system of claim 22 , wherein the plasma pistons are electromagnetically pinned in place at the target plasma by forcing current through the plasma pistons to provide a Lorentz force to hold the plasma pistons in place at the target plasma.

Assignees

• Univ New Hampshire

Inventors

• Connell James J

Classifications

• H05H1/06

  Longitudinal pinch devices · CPC title

• H05H1/14 Primary

  wherein the containment vessel is straight and has magnetic mirrors · CPC title

• G21B1/15 Primary

  Particle injectors for producing thermonuclear fusion reactions, e.g. pellet injectors · CPC title

• G21B1/052

  reversed field configuration · CPC title

• G21B3/008

  Fusion by pressure waves · CPC title