Plasma generator with permanent magnet divertor

Patent metadata

Field	Value
Publication number	US-11923095-B2
Application number	US-202117461366-A
Country	US
Kind code	B2
Filing date	Aug 30, 2021
Priority date	Aug 30, 2021
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

A divertor for system supporting plasma for fusion employs permanent magnets providing far weaker magnetic field strength than conventionally used in cryogenic magnetic systems through an ability to place the permanent magnets in close proximity to the plasma containment volume.

First claim

What we claim is:

1. An apparatus for producing plasma having an energy that allows for nuclear fusion, comprising:
a containment volume within a vessel;
an extraction volume outside of the containment volume;
a containment field magnet structure providing containment magnetic flux lines, wherein the containment magnetic flux lines are configured to provide cyclonic retention of plasma ions at nuclear fusion energies in the containment volume; and
a divertor magnet structure of permanent magnets located adjacent to the containment volume,
wherein the divertor magnet structure is positioned to create an X point of zero magnetic field,
wherein the X point allows plasma ions at a periphery of the containment volume to escape into the extraction volume.

2. The apparatus of claim 1 further including a neutron absorption structure surrounding the containment volume and absorbing neutron energy, and wherein the divertor magnet structure is between the neutron absorption structure and the containment volume.

3. The apparatus of claim 2 wherein the neutron absorption structure provides at least one of: (a) a reaction volume to receive neutrons therethrough and containing an element for transmutation into a different element and (b) at least portions of an electrical generator receiving neutrons from the reaction volume to generate electrical power.

4. The apparatus of claim 1 further including a thermal absorption structure surrounding the containment volume providing cooling channels for receiving circulating coolant, and wherein the divertor magnet structure is between the thermal absorption structure and the containment volume.

5. The apparatus of claim 1 further including a coolant flow system providing coolant flow conduits in thermal communication with permanent magnets, a coolant flow pump, and a coolant cooler to recirculate coolant to extract heat from the divertor magnet structure.

6. The apparatus of claim 1 wherein the divertor magnet structure provides a first hoop of permanent magnet material generating flux lines in the containment volume counter to the containment magnetic flux lines.

7. The apparatus of claim 6 wherein the divertor magnet structure provides a Halbach array further including second and third hoops together flanking the first hoop and having magnetic polarization with opposite polarity to each other.

8. The apparatus of claim 1 further including walls separating the containment volume from the extraction volume and providing an opening centered about the X point, the walls extending away from a plane perpendicular to the containment magnetic flux lines as the walls extend away from the opening.

9. The apparatus of claim 1 wherein the containment field magnet structure provides a mirror containment field providing axially-extending magnetic flux lines converging at opposed first and second ends of the containment volume providing ion turnaround points and wherein the divertor magnet structure is placed toward a center position between the first and second ends.

10. The apparatus of claim 9 further including multiple divertor magnet structures placed symmetrically with respect to a center position between the first and second ends.

11. The apparatus of claim 1 wherein the containment field magnet structure provides a mirror containment field providing axially-extending magnetic flux lines converging at opposed first and second ends of the containment volume providing ion turnaround points and wherein the divertor magnet structure includes a first and second divertor magnet structure placed at corresponding first and second ends outside of the turnaround points for plasma ions at fusion energies.

12. The apparatus of claim 1 wherein the containment field magnet structure provides a toroidal containment volume.

13. The apparatus of claim 1 further including a target in the extraction volume presenting a face for receiving escaping plasma ions and deflecting the escaping plasma ions into a walled chamber outside of the containment volume.

14. The apparatus of claim 1 further including a permanent magnet shield layer positioned between the permanent magnet and the containment volume.

15. The apparatus of claim 1 further wherein the permanent magnets are rare earth alloys having magnetization of greater than 1 T.

16. The apparatus of claim 1 further wherein the permanent magnets are iron nitride magnets.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Forest Cary Brett
• Pizzo Jonathan
• Schmitz Oliver

Classifications

• H05H1/105

  using magnetic pumping · CPC title

• H05H1/11

  using cusp configuration (H05H1/14 takes precedence) · CPC title

• H05H1/12

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

• H05H1/14

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

• Y02E30/10

  Nuclear fusion reactors · CPC title