# US 12,770,744 B2 · Plasma compression system utilizing poloidal field coils > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,770,744 B2 - Document ID: US12770744B2 - Status: Granted - Kind: B2 - Application number: 18/844,363 - Filed: 2023-03-14 - Published: 2025-06-12 - Granted: 2026-10-20 - Earliest claimed: 2022-03-14 - Assignees: General Fusion Inc. - Applicants: General Fusion Inc. - Inventors: Stephen James Howard; Meritt Wayne Reynolds; Michel Laberge; Alexander Douglas Mossman; David Plant; Celso Ribeiro - Web page: https://patentgrep.com/patent/US12770744B2 ## CPC - G21B 1/05: with magnetic or electric plasma confinement - G21B: FUSION REACTORS (uncontrolled reactors G21J) ## Abstract Examples of a plasma compression system are disclosed. The system includes a metallic vessel configured to receive and contain a plasma. The system further includes a metallic liquid liner in the vessel and at least partially bounding a plasma compression region having a longitudinal axis, and means for moving the liquid liner inwardly towards the longitudinal axis to compress the plasma in the plasma compression region. The system further includes a plurality of electrically conductive coils outside the plasma compression region and configured to generate a poloidal magnetic field in the liquid liner and the plasma compression region. At least some of the poloidal magnetic field within the plasma compression region extends along the longitudinal axis, and at least some of the poloidal magnetic field in the liquid liner moves inwardly towards the longitudinal axis with the liquid liner as the liquid liner moves towards the longitudinal axis. ## Claims ### Claim 1 A plasma compression system comprising: a vessel configured to receive and contain a plasma and a metallic liquid medium circulating around a longitudinal rotation axis so as to at least partially bound a plasma compression region configured to receive and contain the plasma; a plurality of drivers configured to controllably reduce a volume of the plasma compression region by inwardly moving the liquid medium towards the longitudinal rotation axis, the liquid medium compressing the plasma; and a plurality of electrically conductive coils outside the plasma compression region and configured to generate a poloidal magnetic field in the vessel, the liquid medium, and the plasma compression region, at least some of the poloidal magnetic field within the plasma compression region extending along the longitudinal rotation axis, and at least some of the poloidal magnetic field in the liquid medium moving inwardly towards the longitudinal rotation axis with the liquid medium as the liquid medium moves towards the longitudinal rotation axis. ### Claim 2 (depends on 1) The plasma compression system of claim 1, wherein the vessel comprises a ferromagnetic or ferrimagnetic material. ### Claim 3 (depends on 2) The plasma compression system of claim 2, wherein the plurality of electrically conductive coils are positioned relative to a wall of the vessel such that the vessel wall concentrates the poloidal magnetic field in the plasma compression region. ### Claim 4 (depends on 1) The plasma compression system of claim 1, wherein the plurality of electrically conductive coils comprises at least two substantially ring-shaped coils positioned substantially symmetrically around and substantially perpendicularly to the longitudinal rotation axis, the at least two substantially ring-shaped coils at different corresponding locations along the longitudinal rotation axis. ### Claim 5 (depends on 1) The plasma compression system of claim 1, wherein the plurality of electrically conductive coils comprises at least a first coil and a second coil spaced from and substantially parallel to the first coil, wherein the plasma compression region is between the first and second coils. ### Claim 6 (depends on 1) The plasma compression system of claim 1, wherein the vessel comprises wall portions having an inner radius in a range of 3.5 m to 5.5 m along a direction substantially perpendicular to the wall portions. ### Claim 7 (depends on 6) The plasma compression system of claim 6, further comprising a metallic rotating core inside the vessel, the rotating core configured to rotate about the longitudinal rotation axis, and at least portions of the rotating core having an inner radius in a range of 1.5 m to 3 m along the direction substantially perpendicular to the wall portions. ### Claim 8 (depends on 1) The plasma compression system of claim 1, further comprising a first electrical power source configured to flow substantially constant electric current in the plurality of electrically conductive coils while the liquid medium compresses the plasma. ### Claim 9 (depends on 8) The plasma compression system of claim 8, wherein the first electrical power source is configured to flow the electric current with an AC component and a DC component, wherein the AC component has a frequency that is less than 10 Hz and a magnitude less than 10% of a magnitude of the DC component. ### Claim 10 (depends on 8) The plasma compression system of claim 8, wherein the electrical power source is configured to flow a substantially constant electric current over a lifetime of the plasma within the plasma compression region. ### Claim 11 (depends on 1) The plasma compression system of claim 1, wherein a second electrical power source is coupled to a plurality of formation field coils and is configured to generate a formation magnetic field at the centerline (equatorial plane) of the vessel cavity in a range of 100 mWb to 700 mWb within the plasma compression region. ### Claim 12 (depends on 1) The plasma compression system of claim 1, wherein the plurality of drivers comprises a plurality of mechanical drivers. ### Claim 13 (depends on 1) The plasma compression system of claim 1, wherein the plurality of drivers comprises acoustic waves impinging upon the liquid medium. ### Claim 14 (depends on 1) The plasma compression system of claim 1, wherein the plurality of drivers comprises explosive gas or compressed gas applying a force to move the liquid medium. ### Claim 15 A plasma compression system comprising: a metallic vessel configured to receive and contain a plasma; a metallic liquid liner in the vessel and at least partially bounding a plasma compression region having a longitudinal axis; a plurality of drivers configured to move the liquid liner inwardly towards the longitudinal axis to compress the plasma in the plasma compression region; and a plurality of electrically conductive coils outside the plasma compression region and configured to generate a poloidal magnetic field in the liquid liner and the plasma compression region, at least some of the poloidal magnetic field within the plasma compression region extending along the longitudinal axis, and at least some of the poloidal magnetic field in the liquid liner moving inwardly towards the longitudinal axis with the liquid liner as the liquid liner moves towards the longitudinal axis. ### Claim 16 (depends on 15) The plasma compression system of claim 15, wherein the vessel is ferromagnetic or ferrimagnetic. ### Claim 17 (depends on 15) The plasma compression system of claim 15, wherein the plurality of electrically conductive coils are positioned relative to a wall of the vessel such that the vessel wall at least partially concentrates the poloidal magnetic field within the plasma compression region. ### Claim 18 (depends on 15) The plasma compression system of claim 15, wherein the plasma is substantially toroidal and substantially symmetric about the longitudinal axis, at least some of the poloidal magnetic field in the plasma compression region extending along a poloidal direction relative to the substantially toroidal plasma. ### Claim 19 (depends on 15) The plasma compression system of claim 15, further comprising a first electrical power source coupled to the electrically conductive coils and configured to generate the poloidal magnetic field within the plasma compression region with a strength sufficient to inhibit the plasma from impinging the liquid liner. ### Claim 20 (depends on 15) The plasma compression system of claim 15, wherein the plurality of electrically conductive coils comprises at least two substantially ring-shaped coils positioned substantially symmetrically around and substantially perpendicularly to the longitudinal axis, the at least two substantially ring-shaped coils at different corresponding locations along the longitudinal axis. ### Claim 21 (depends on 15) The plasma compression system of claim 15, further comprising a rotating core and a liquid medium in the vessel, the rotating core configured to rotate and circulate the liquid medium to form the liquid liner and the plasma compression region. ### Claim 22 (depends on 21) The plasma compression system of claim 21, wherein the rotating core has an outer surface that is spaced from an inner surface of the vessel by a gap, and the plurality of drivers comprises a plurality of implosion drivers extending through the rotating core from the gap to the plasma compression region and containing at least some of the liquid medium. ### Claim 23 (depends on 22) The plasma compression system of claim 22, further comprising a pressurized fluid source in fluid communication with the plurality of implosion drivers, wherein the pressurized fluid source is configured to controllably apply pressurized gas to the plurality of implosion drivers, thereby causing the implosion drivers to apply pressure pulses to the liquid medium such that the liquid liner is pushed inwards to collapse the plasma compression region and compress the plasma within the plasma compression region. ### Claim 24 (depends on 15) The plasma compression system of claim 15, wherein the plurality of drivers further comprises: a plurality of compression drivers fixedly mounted to an outer surface of the vessel, and in fluid communication with the plurality of implosion drivers; a compression fluid in the gap and in fluid communication the compression drivers and implosion drivers; and a pressurized fluid source in fluid communication with the plurality of compression drivers, wherein the pressurized fluid source is configured to controllably apply pressurized gas to the plurality of compression drivers, thereby causing the compression drives to apply first pressure pulses via the compression fluid to the plurality of implosion drivers, and thereby causing the implosion drivers to apply second pressure pulses to the liquid medium such that the liquid liner is pushed inwards to collapse the plasma compression region and compress the plasma within the plasma compression region. ### Claim 25 (depends on 15) The plasma compression system of claim 15, further comprising a plasma injector in fluid communication with the vessel and configured to inject the plasma into the plasma compression region. ### Claim 26 (depends on 15) The plasma compression system of claim 15, wherein the plurality of drivers comprises at least one of: a plurality of mechanical drivers; acoustic waves impinging upon the liquid medium; explosive gas or compressed gas applying a force to move the liquid medium. ### Claim 27 A method comprising: injecting a magnetized toroidal plasma into a plasma compression region, the plasma compression region at least partially bounded by a metallic liquid liner having a longitudinal axis; generating a poloidal magnetic field within the liquid liner and the plasma compression region, at least some of the poloidal magnetic field in the plasma compression region extending along the longitudinal axis; and moving the liquid liner towards the longitudinal axis thereby reducing a volume of the plasma compression region containing the plasma and compressing the plasma, at least some of the poloidal magnetic field in the liquid liner moving inwardly towards the longitudinal axis with the liquid liner as the liquid liner moves towards the longitudinal axis. ### Claim 28 (depends on 27) The method of claim 27, wherein said generating poloidal magnetic field comprises flowing electrical current through a plurality of coils external to the plasma compression region. ### Claim 29 (depends on 28) The method of claim 28, wherein, during said compressing, the electric current is substantially constant. ### Claim 30 (depends on 27) The method of claim 27, wherein said compressing the liquid liner comprises adjusting a trajectory of the liquid liner to dynamically adjust the poloidal magnetic field within the plasma compression region. ### Claim 31 (depends on 27) The method of claim 27, further comprising rotating a metallic liquid medium to form the metallic liquid liner, wherein the liquid liner rotates around a rotation axis symmetric with the longitudinal axis.