Systems and methods for FRC plasma position stability

Patent metadata

Field	Value
Publication number	US-11217351-B2
Application number	US-201815976532-A
Country	US
Kind code	B2
Filing date	May 10, 2018
Priority date	Nov 13, 2015
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

Systems and methods are provided that facilitate stability of an FRC plasma in both radial and axial directions and axial position control of an FRC plasma along the symmetry axis of an FRC plasma chamber. The systems and methods exploit an axially unstable equilibria of the FRC plasma to enforce radial stability, while stabilizing or controlling the axial instability. The systems and methods provide feedback control of the FRC plasma axial position independent of the stability properties of the plasma equilibrium by acting on the voltages applied to a set of external coils concentric with the plasma and using a non-linear control technique.

First claim

What is claimed is:

1. A method for stabilizing a field reversed configuration (FRC) plasma comprising the steps of:
forming an FRC plasma positioned along a longitudinal axis of a confinement chamber adjacent a mid-plane of the confinement chamber by forming an FRC magnetic field about a rotating plasma in the confinement chamber;
stabilizing the FRC plasma in a radial direction normal to the longitudinal axis to position the FRC plasma axisymmetric about the longitudinal axis by adjusting an applied magnetic field to induce radial stability and axial instability in the FRC plasma; and
stabilizing the FRC plasma in an axial direction along the longitudinal axis by adjusting first and second radial magnetic fields, wherein the first and second radial magnetic fields interact with the FRC magnetic field to axially move the FRC plasma to position the FRC plasma axisymmetric about the mid-plane.

2. The method of claim 1 further comprising the step of generating an applied magnetic field within the chamber with quasi-dc coils encircling the confinement chamber and extending axially along the confinement chamber.

3. The method of claim 1 further comprising the step of axially injecting plasma into the FRC plasma from axially mounted plasma guns.

4. The method of claim 1 wherein the first and second radial magnetic fields are antisymmetric about the mid-plane.

5. The method of claim 4 wherein the first and second radial magnetic fields are generated due to currents induced in counter directions in first and second radial coils positioned about the confinement chamber.

6. The method of claim 1 wherein the step of stabilizing the FRC plasma includes monitoring the position of the FRC plasma.

7. The method of claim 6 wherein the step of monitoring the position of the FRC plasma includes monitoring magnetic measurements associated with the FRC plasma.

8. The method of claim 6 further comprising the step of measuring current in the first and second radial coils.

9. The method of claim 8 further comprising the step of monitoring the velocity of the FRC plasma.

10. The method of claim 1 further comprising maintaining one or more of plasma thermal energy, plasma particle count, plasma radius, plasma length and magnetic flux of the FRC plasma at or about a constant value without decay by injecting beams of fast neutral atoms from neutral beam injectors into the FRC plasma at an angle towards the mid-plane of the confinement chamber and injecting a compact toroid plasma into the FRC plasma.

11. The method of claim 10 further comprising the step of generating a mirror magnetic field within opposing ends of the confinement chamber with quasi-dc mirror coils extending about the opposing ends of the confinement chamber.

12. The method of claim 1 wherein the step of the forming the FRC plasma includes forming a formation FRC plasma in a first formation section coupled to an end of the confinement chamber and accelerating the formation FRC plasma towards the mid-plane of the confinement chamber to form the FRC plasma.

13. The method of claim 12 wherein the step of the forming the FRC plasma includes forming a second formation FRC plasma in a second formation section coupled to a second end of the confinement chamber and accelerating the second formation FRC plasma towards the mid-plane of the confinement chamber where the two formation FRC plasmas merge to form the FRC plasma.

14. The method of claim 12 wherein the step of forming the FRC plasma includes one of forming a formation FRC plasma while accelerating the formation FRC plasma towards the mid-plane of the confinement chamber and forming a formation FRC plasma then accelerating the formation FRC plasma towards the mid-plane of the confinement chamber.

15. The method of claim 13 further comprising the step of guiding magnetic flux surfaces of the FRC magnetic field into diverters coupled to the ends of the first and second formation sections.

16. The method of claim 1 further comprising the step of conditioning the internal surfaces of the chamber, formation sections, and diverters with a gettering system.

17. The method of claim 16 wherein the gettering system includes one of a Titanium deposition system and a Lithium deposition system.

18. The method of claim 1 further comprising the step of controlling a radial electric field profile in an edge layer of the FRC plasma.

19. The method of claim 18 wherein the step of controlling the radial electric field profile in the edge layer of the FRC plasma includes applying a distribution of electric potential to a group of open flux surfaces of the FRC plasma with biasing electrodes.

Assignees

• Tae Tech Inc

Inventors

• Gonzalez Jesus Antonio Romero

Classifications

• H05H1/02

  Arrangements for confining plasma by electric or magnetic fields; Arrangements for heating plasma ({G21B1/00 takes precedence;} electron optics H01J) · CPC title

• G21B1/05 Primary

  with magnetic or electric plasma confinement · CPC title

• G21B1/17

  Vacuum chambers; Vacuum systems · CPC title

• Y02E30/10

  Nuclear fusion reactors · CPC title

• H05H1/12 Primary

  wherein the containment vessel forms a closed or nearly closed loop {(G21B1/05 takes precedence)} · CPC title