Stochastic Mantle for Magnetic Fusion Devices

Abstract

All magnetic nuclear fusion devices face common technical challenges related to power and particle control arising from the close proximity of a thermonuclear plasma to the plasma-facing component. The plasma-facing component is subjected to high incident power density and erosion processes, and must facilitate the efficient remove of the fusion-ash. In the past, limiters and divertors have been used in magnetic fusion devices for this purpose. These are discussed and extended to a new concept, the stochastic mantle, which utilizes a stochastic magnetic field layer to disperse power on the plasma-facing component to the maximum extent possible. Further, if operated at sufficient plasma collisionality, it reduces the energy of particles incident on the plasma-facing component, globally reducing erosion by physical sputtering, while producing high gas pressures for fusion-ash removal through pumping ducts. The approach is particular suited for stellarators, but others devices may be considered.

Claims

1. A stellarator fusion reactor comprising: a core plasma, said core plasma being configured by a core magnetic geometry, said core magnetic geometry comprising nested, closed, three-dimensional toroidal magnetic flux surfaces, said core magnetic geometry being created by a combination of external magnets and internal electric currents flowing within said core plasma; said core magnetic geometry confining said core plasma against energy losses by particle and thermal transport across and along magnetic field lines, allowing attainment of thermonuclear plasma conditions, resulting in nuclear fusion reactivity, generating energetic fusion product particles, said energetic fusion product particles comprising neutrons and ions; a surrounding plasma chamber, said surrounding plasma chamber encompassing said core plasma and having an interior plasma-facing component, said interior plasma-facing component being actively-cooled in order to receive power leaving said core plasma, while maintaining said interior plasma-facing component within engineering limits for power removal; a stochastic mantle, said stochastic mantle being formed and disposed outside of said core magnetic geometry, having a stochastic magnetic field, said stochastic magnetic field having magnetic fields lines circumnavigating said stellarator fusion reactor, moving in a toroidal direction, diffusing randomly in both a radial direction and a poloidal direction, a portion of said magnetic fields lines intersecting said internal plasma-facing component of said surrounding plasma chamber; a mantle plasma, said mantle plasma being present in said stochastic mantle, said mantle plasma comprising ions, electrons, atoms and molecules; a fusion-ash, said fusion-ash comprising particles created as energetic fusion ions, after said energetic fusion ions lose energy and reach a temperature of local conditions in said core plasma and said mantle plasma; a conducted power, said conducted power being created in said core plasma and moving to a periphery of said core plasma; said stochastic mantle conveying said conducted power to said interior plasma-facing component along said stochastic magnetic field by particle and thermal transport; and said stochastic magnetic field being created and configured with said combination of external magnets and internal electric currents flowing within said core plasma to provide uniform deposition of said conducted power on a surface of said interior plasma-facing component.

2. The stellarator fusion reactor, as described in claim 1, wherein said stochastic mantle further comprises: a last closed flux surface (LCFS), said LCFS marking an outer most flux surface of said core magnetic geometry, said LCFS providing a boundary between said core plasma and said mantle plasma; said stochastic magnetic field ensures that parallel plasma transport processes in said mantle plasma result in similar plasma transport processes in said radial direction; said mantle plasma being subject to heat conduction, convection and electromagnetic radiation; a connection length L, said connection length L being a distance from a location within said stochastic mantle along said stochastic magnetic field and intersecting said interior plasma-facing component, said connection length L being a maximum for field lines originating adjacent said LCFS; and said mantle plasma having a high collisionality, said high collisionality arising from an electron mean free path along field lines shorter than said connection length L from said LCFS throughout said stochastic mantle.

3. The stellarator fusion reactor, as described in claim 2, wherein said stochastic mantle further comprises: an opaque condition within said mantle plasma, said opaque condition arising due to plasma density and temperature levels in said mantle plasma, said opaque condition ensuring that said atoms and said molecules entering said stochastic mantle adjacent said interior plasma-facing component are screened by ionization processes within said mantle plasma before reaching said LCFS; said opaque condition within said stochastic mantle ensuring said conducted power coming from said core plasma enters said stochastic mantle by conduction; and said opaque condition within said stochastic mantle, preventing creation of energetic atoms by charge-exchange processes inside said LCFS, preventing energy loss by said energetic atoms from said core plasma; and eliminating potential for physical sputtering by said energetic atoms of said interior plasma-facing component.

4. The stellarator fusion reactor, as described in claim 3, wherein said stochastic mantle further comprises: a conduction-limited layer, said conduction-limited layer transmitting power by parallel electron heat conduction; said stochastic magnetic field ensuring said parallel electron heat conduction results in radial electron heat conduction; said conduction-limited layer being disposed adjacent said LCFS and extending radially outward into said stochastic mantle, said conduction-limited layer resulting from high plasma collisionality and an absence of convection resulting from said opaque plasma condition; said conduction-limited layer, supports a first mantle plasma temperature adjacent said LCFS and a second, lower mantle plasma temperature adjacent said interior plasma-facing component; said second lower mantle plasma temperature adjacent to said interior plasma-facing component ensuring lower particle energies for particles striking said interior plasma-facing component, said low particle energies reducing physical sputtering, thereby reducing erosion of said interior plasma-facing component; a mantle plasma pressure, said mantle plasma pressure being within said stochastic mantle and being a product of a mantle plasma density and said second, lower mantle plasma temperature; and said conduction-limited layer and said absence of convection ensuring that said mantle plasma pressure is conserved along said stochastic magnetic field in said conduction-limited layer, a radial decrease in said second, lower plasma temperature resulting in a radial rise in said mantle plasma density within said conduction-limited layer.

5. The stellarator fusion reactor, as described in claim 4, wherein said stochastic mantle further comprises: a dissipative layer, said dissipative layer comprising said atoms and said molecules, interaction between said mantle plasma and said atoms and said molecules resulting in dissipative processes; said dissipative layer being located in a region of said second, lower mantle plasma temperature outside of said conduction-limited layer and adjacent said interior plasma-facing component as a result of said opaque condition; said dissipative processes within the dissipative layer comprise ionization of said atoms and said molecules, dissociation of said molecules, an atomic radiative process, molecular radiative processes, bremsstrahlung radiation from said electrons in said mantle plasma, recombination processes and a molecule formation process; said dissipative processes occurring in a volume of said dissipative layer and adjacent to said surface of said interior plasma-facing component; said fusion-ash being present in said mantle plasma, said fusion-ash becoming said fusion-ash gas by said recombination processes; said dissipative processes reducing said second, lower mantle plasma temperature in said dissipative layer adjacent said interior plasma-facing component, ensuring lower particle energies for particles striking said interior plasma-facing component, said lower particle energies reducing said physical sputtering, thereby reducing erosion of said interior plasma-facing component; a gas pressure, said gas pressure within the dissipative layer, adjacent said plasma-facing component, being a sum of a pressure of said atoms, a pressure of said molecules and a pressure of said fusion-ash gas; said dissipative layer increasing said gas pressure adjacent said interior plasma-facing component, facilitating removal of gas and said fusion-ash gas through pumping ducts exiting said surrounding plasma chamber through vacuum pumps; and said gas and fusion-ash gas surrounding said periphery of said core plasma, allowing placement of said pumping ducts around said periphery of said core plasma.

6. A magnetic fusion device, comprising: a toroidal fusion plasma having a toroidal fusion core plasma, said toroidal fusion core plasma created by a combination of external magnets and internal electric currents flowing within said toroidal fusion core plasma; said toroidal fusion core plasma having energy losses by particle and thermal transport across and along magnetic field lines, said energy losses carrying power to a periphery of said toroidal fusion core plasma; said magnetic fusion device having a surrounding plasma chamber, said surrounding plasma chamber encompassing said core plasma and having an interior plasma-facing component, said interior plasma-facing component being actively-cooled in order to receive said power, while maintaining said interior plasma-facing component within engineering limits for power removal; a stochastic mantle, said stochastic mantle comprising mantle plasma and being disposed outside of said toroidal fusion core plasma, having a stochastic magnetic field, said stochastic magnetic field having magnetic fields lines circumnavigating said toroidal fusion plasma, moving in a toroidal direction, diffusing in both radial and poloidal directions, a first portion of said magnetic fields lines intersecting said internal plasma-facing component of said surrounding plasma chamber; said stochastic mantle allowing energy losses from said toroidal fusion core plasma to said interior plasma-facing component along said magnetic field lines by particle and thermal transport; said stochastic mantle being generated without degrading confinement of said toroidal fusion core plasma; said stochastic mantle being configured with said magnetic field lines providing a flux of particles, plasma momentum and energy along said magnetic field lines corresponding to radial flux based on said stochastic magnetic field; said first portion of said magnetic field lines intersecting with said interior plasma-facing component being configured with said combination of external magnets and internal electric currents flowing within said toroidal fusion core plasma to provide uniform deposition of said power incident on a surface of said interior plasma-facing component; said stochastic mantle separating said toroidal fusion core plasma from said interior plasma-facing component, having a first radial width and high collisionality, said first radial width and said high collisionality, permitting development of parallel-field plasma temperature gradients and dissipative processes, said parallel-field plasma temperature gradients and dissipative processes providing cold plasma conditions adjacent said interior plasma-facing component; said cold plasma conditions adjacent to said interior plasma-facing component providing low particle energies for said particles striking said interior plasma-facing component, said low particle energies being below a threshold for physical sputtering, thereby preventing erosion of said interior plasma-facing component; said dissipative processes within said stochastic mantle, comprising plasma-neutral interactions with neutral particles, said plasma-neutral interactions elevating gas pressure adjacent said interior plasma-facing component, facilitating removal of fusion-ash gas through pumping ducts connected to vacuum pumps; said gas pressure and fusion-ash gas surround said periphery of said toroidal fusion core plasma, permitting placement of said pumping ducts around said periphery of said core plasma; said stochastic mantle comprising an inner, conduction-limited layer, said inner conduction-limited layer, transmitting power by parallel electron heat conduction, and an outer, dissipative layer, said outer dissipative layer comprising atoms and molecules and providing dissipative processes by an interaction of said mantle plasma with said atoms and said molecules; and said stochastic mantle protecting said interior plasma-facing component of the magnetic fusion device, as said stochastic mantle is global and uniform.

7. The stellarator fusion reactor, as described in claim 1, further comprising: an energetic fusion product ion loss process, said energetic fusion product ion loss process arising from a portion of energetic fusion product ions not transferring energy to said core plasma, said portion of said energetic fusion product ions escaping said core plasma, reaching said periphery of said core plasma; and said stochastic mantle providing protection of said interior plasma-facing component against said energetic fusion product ion loss process, said protection provided by said mantle plasma, including said atoms and said molecules, reducing energy of said energetic fusion product ions exiting from said core plasma through a friction process, globally protecting said interior plasma-facing components from excessive local incident power density and damage.

8. The magnetic fusion device as described in claim 6, further comprising: an energetic fusion product ion loss process, said energetic fusion product ion loss process arising from a portion of energetic fusion product ions not transferring energy to said toroidal fusion core plasma, said portion of said energetic fusion product ions escaping said toroidal fusion core plasma, reaching said periphery of said toroidal fusion core plasma; and said stochastic mantle providing protection of said interior plasma-facing component against said energetic fusion product ion loss process, said protection provided by said mantle plasma, including said atoms and said molecules, reducing energy of said energetic fusion product ions exiting from said toroidal fusion core plasma through a friction process, globally protecting said interior plasma-facing components from excessive local incident power density and damage.

Description

DESCRIPTION OF THE DRAWINGS

[0077] FIG. 1 is a vertical section through a generic toroidal magnetic fusion device showing its basic features and reference directions, i.e. toroidal, radial and poloidal directions. C/L refers to the center-line of the toroidal magnetic fusion device.

[0078] FIG. 2 is a vertical section through a generic toroidal magnetic fusion device showing the utilization of the stochastic mantle to define the plasma boundary and its relationship to the core plasma and the plasma-facing component. C/L refers to the center-line of the toroidal magnetic fusion device.

[0079] FIG. 3 is a vertical section through a stellarator fusion reactor showing the utilization of the stochastic mantle to define the plasma boundary. Note, the use of divertor plates and divertor baffles are not required, allowing freedom with respect to the location of pumping ducts and vacuum pumps. Nuclear shielding associated with the pumping duct is not shown. C/L refers to the center-line of the stellarator fusion reactor.

[0080] FIG. 4 Is a graph illustrating the radial dependencies of plasma conditions within the core plasma (confined) and stochastic mantle (mantle plasma) of a stellarator fusion reactor, including plasma temperature, density and pressure, and gas pressure, under conditions of a stochastic magnetic field within the mantle plasma and high plasma collisionality. The conduction-limited and dissipative layers are indicated.

[0081] FIG. 5 is a vertical section through a magnetic fusion device with toroidal geometry showing the utilization of the stochastic mantle to define the plasma boundary. Note, the use of divertor plates and divertor baffles are not required, allowing freedom with respect to the location of pumping ducts and vacuum pumps. Nuclear shielding associated with the pumping duct is not shown. C/L refers to the center-line of the magnetic fusion device.

[0082] FIG. 6 Is a graph illustrating the radial dependencies of plasma conditions within the core plasma (confined) and stochastic mantle (mantle plasma) of a magnetic fusion device, including plasma temperature, density and pressure, and gas pressure, under conditions of a stochastic magnetic field within the mantle plasma and high plasma collisionality. The conduction-limited and dissipative layers are indicated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0083] 1) As illustrated in FIGS. 3 and 4, a stellarator fusion reactor 100 satisfying the objectives identified above can be constructed from the following components. A core plasma 10 is provided. The core plasma 10 is configured by a core magnetic geometry. The core magnetic geometry includes nested, closed, three-dimensional toroidal magnetic flux surfaces 30 as shown in FIG. 3. The core magnetic geometry is created by a combination of external magnets and internal electric currents flowing within the core plasma 10. The core magnetic geometry confines the core plasma 10 against energy losses by particle and thermal transport across and along magnetic field lines. This confinement allows attainment of thermonuclear plasma conditions, resulting in nuclear fusion reactivity and generating energetic fusion product particles. The energetic fusion product particles include neutrons and ions.

[0084] A surrounding plasma chamber 11 is provided. The surrounding plasma chamber 11 has an interior plasma-facing component 1. The interior plasma-facing component 1 is actively-cooled in order to receive power leaving the core plasma 10, while maintaining the interior plasma-facing component 1 within engineering limits for power removal. A stochastic mantle 12 is provided. The stochastic mantle 12 is located outside of the core magnetic geometry and has a stochastic magnetic field. The stochastic magnetic field has magnetic fields lines circumnavigating the stellarator fusion reactor 100, moving in a toroidal direction 2, diffusing randomly in both a radial direction 3 and a poloidal direction 4, as illustrated in FIG. 1. A portion of the magnetic field lines intersect the internal plasma-facing component 1 of the surrounding plasma chamber 11, as shown in FIG. 3.

[0085] A mantle plasma 13 is provided. The mantle plasma 13 is present in the stochastic mantle 12. The mantle plasma 13 includes ions, electrons, atoms and molecules. A fusion-ash is created. The fusion-ash includes particles created as energetic fusion ions, after the energetic fusion ions lose energy and reach a temperature of local conditions in the core plasma 10 and the mantle plasma 13. A conducted power is created. The conducted power is created in the core plasma 10 and moves to a periphery of the core plasma 10. The stochastic mantle 12 conveys the conducted power to the interior plasma-facing component 1 along the stochastic magnetic field by particle and thermal transport. The stochastic magnetic field is configured with the combination of external magnets and internal electric currents flowing within the core plasma 10 to provide uniform deposition of the conducted power on a surface of the interior plasma-facing component 1.

[0086] 2) In a variant of the invention, the stochastic mantle 12 further includes a last closed flux surface (LCFS) 14. The LCFS 14 marks an outer most flux surface of the core magnetic geometry. The LCFS 14 provides a boundary between the core plasma 10 and the mantle plasma 13. The stochastic magnetic field ensures that parallel plasma transport processes in the mantle plasma 13 result in similar plasma transport processes in the radial direction 3. The mantle plasma 13 is subject to heat conduction, convection and electromagnetic radiation.

[0087] A connection length L is provided. The connection length L is a distance from a location within the stochastic mantle 12 along the stochastic magnetic field which intersects the interior plasma-facing component 1. The connection length L is a maximum for field lines originating adjacent the LCFS 14. The mantle plasma 13 has a high collisionality. The high collisionality arises from an electron mean free path along field lines shorter than the connection length L from the LCFS throughout the stochastic mantle 12.

[0088] 3) In another variant, the stochastic mantle 12 further includes an opaque condition within the mantle plasma 13. The opaque condition ensures that the atoms and the molecules entering the stochastic mantle 12 adjacent the interior plasma-facing component 1 are screened by ionization processes within the mantle plasma 13 before reaching the LCFS 14. The opaque condition within the stochastic mantle 12 ensures that the conducted power coming from the core plasma 10 enters the stochastic mantle 12 by conduction.

[0089] The opaque condition within the stochastic mantle 12, prevents creation of energetic atoms by charge-exchange processes inside the LCFS 14, preventing energy loss by the energetic atoms from the core plasma 10 and eliminating potential for physical sputtering by the energetic atoms of the interior plasma-facing component 1.

[0090] 4) In still another variant, as illustrated in FIGS. 3 and 4, the stochastic mantle 12 further includes a conduction-limited layer 20. The conduction-limited layer 20 transmits power by parallel electron heat conduction. The stochastic magnetic field ensures that the parallel electron heat conduction results in radial electron heat conduction. The conduction-limited layer 20 is located adjacent to the LCFS 14 and extends radially outward into the stochastic mantle 12. The conduction-limited layer 20 results from high plasma collisionality and an absence of convection resulting from the opaque plasma condition. The conduction-limited layer 20 supports a first mantle plasma temperature 21 adjacent the LCFS 14 and a second, lower mantle plasma temperature 22 adjacent the interior plasma-facing component 1.

[0091] The second lower mantle plasma temperature 22 adjacent to the interior plasma-facing component 1 ensures lower particle energies for particles striking the interior plasma-facing component 1. The low particle energies reduce physical sputtering, thereby reducing erosion of the interior plasma-facing component 1. A mantle plasma pressure 23 is created. The mantle plasma pressure 23 is created within the stochastic mantle 12 and is a product of a mantleplasma density 24 and the second, lower mantle plasma temperature 22. The conduction-limited layer 20 and the absence of convection ensures that the mantle plasma pressure 23 is conserved along the stochastic magnetic field in the conduction-limited layer 20. A radial decrease in the second, lower plasma temperature 22 results in a radial rise 25 in the mantle plasma density 24 within the conduction-limited layer 20.

[0092] 5) In still another variant, the stochastic mantle 12 further includes a dissipative layer 26. The dissipative layer 26 includes the atoms and the molecules. Interaction between the mantle plasma 13 and the atoms and the molecules results in dissipative processes. The dissipative layer 26 is located in a region of the second, lower mantle plasma temperature 22 outside of the conduction-limited layer 20 and adjacent the interior plasma-facing component 1 as a result of the opaque condition.

[0093] The dissipative processes within the dissipative layer 26 include ionization of the atoms and the molecules, dissociation of the molecules, an atomic radiative process, molecular radiative processes, bremsstrahlung radiation from the electrons in the mantle plasma 13, recombination processes and a molecule formation process. The dissipative processes occur in a volume of the dissipative layer 26 and adjacent to the surface of the interior plasma-facing component 1. The fusion-ash is present in the mantle plasma 13. The fusion-ash becomes the fusion-ash gas by the recombination processes.

[0094] The dissipative processes reduce the second, lower mantle plasma temperature 22 in the dissipative layer 26 adjacent the interior plasma-facing component 1. This reduced second, lower mantle plasma temperature 22 ensuring lower particle energies for particles striking the interior plasma-facing component 1. The lower particle energies reduce the physical sputtering, thereby reducing erosion of the interior plasma-facing component 1. A gas pressure 27 is created. The gas pressure 27 within the dissipative layer 26, adjacent the plasma-facing component 1, is a sum of a pressure of the atoms, a pressure of the molecules and a pressure of the fusion-ash gas. The dissipative layer 26 increases the gas pressure 27 adjacent the interior plasma-facing component 1 to facilitate removal of gas and the fusion-ash gas through pumping ducts 31 exiting the surrounding plasma chamber 11 through vacuum pumps 32. The gas and fusion-ash gas surrounding the periphery of the core plasma 10, allow placement of the pumping ducts 31 around the periphery of the core plasma 10.

[0095] 6) As illustrated in FIGS. 1, 2, 5 and 6, a magnetic fusion device 101 employing the stochastic mantle 12 technology can be constructed from the following components. A toroidal fusion plasma that has a toroidal fusion core plasma 110 is provided. The toroidal fusion core plasma 110 is created by a combination of external magnets and internal electric currents flowing within the toroidal fusion core plasma 110. The toroidal fusion core plasma 110 has energy losses by particle and thermal transport across and along magnetic field lines, the energy losses carrying power to a periphery of the toroidal fusion core plasma 110. The magnetic fusion device has a surrounding plasma chamber 11. The surrounding plasma chamber 11 has an interior plasma-facing component 1. The interior plasma-facing component 1 is actively-cooled in order to receive the power, while maintaining the interior plasma-facing component 1 within engineering limits for power removal.

[0096] A stochastic mantle 12 is provided. The stochastic mantle 12 includes mantle plasma 13 and is located outside of the toroidal fusion core plasma 110. The stochastic mantle 12 has a stochastic magnetic field. The stochastic magnetic field has magnetic fields lines that circumnavigate the toroidal fusion core plasma 110. The magnetic field lines move in a toroidal direction 2 and diffuse in radial 3 and poloidal 4 directions. A first portion of the magnetic field lines intersect the interior plasma-facing component 1 of the surrounding plasma chamber 11. The stochastic mantle 12 allows energy losses from the toroidal fusion core plasma 110 to the interior plasma-facing component 1 along the magnetic field lines by particle and thermal transport.

[0097] The stochastic mantle 12 is generated without degrading confinement of the toriodal fusion core plasma 110. The stochastic mantle 12 is configured with the magnetic field lines providing a flux of particles, plasma momentum and energy along the magnetic field lines corresponding to radial flux based on the stochastic magnetic field. The first portion of the magnetic field lines that intersects with the interior plasma-facing component 1 is configured with the combination of external magnets and internal electric currents flowing within the toroidal fusion core plasma 110 to provide uniform deposition of the power incident on a surface of the interior plasma-facing component 1. The stochastic mantle 12 separates the toroidal fusion core plasma 110 from the interior plasma-facing component 1. The stochastic mantle 12 has a first radial width and high collisionality. The first radial width and the high collisionality permit development of parallel-field plasma temperature gradients and dissipative processes. The parallel-field plasma temperature gradients and dissipative processes provide cold plasma conditions adjacent the interior plasma-facing component 1.

[0098] The cold plasma conditions adjacent to the interior plasma-facing component 1 provide low particle energies for the particles striking the interior plasma-facing component 1. The low particle energies reduce physical sputtering, thereby reducing erosion of the interior plasma-facing component 1. The dissipative processes within the stochastic mantle include plasma-neutral interactions with neutral particles. The plasma-neutral interactions elevate gas pressure 27 adjacent the interior plasma-facing component 1 to facilitate removal of fusion-ash gas through pumping ducts 31 connected to vacuum pumps 32. The gas pressure 27 and fusion-ash gas surround the periphery of the toroidal fusion core plasma 110 permit placement of the pumping ducts 31 around the periphery of the toroidal fusion core plasma 110.

[0099] The stochastic mantle 12 includes an inner, conduction-limited layer 20 and an outer, dissipative layer 26. The inner conduction-limited layer 20 transmits power by parallel electron heat conduction. The outer, dissipative layer 26, where atoms and molecules are present provides dissipative processes by an interaction of the mantle plasma 13 with the atoms and the molecules. The stochastic mantle 12 protects the interior plasma-facing component 1 of the magnetic fusion device, as the stochastic mantle 12 is global and uniform.

[0100] 7) In a further variant of the invention, as illustrated in FIGS. 3-4, the stellarator fusion reactor 100 further includes an energetic fusion product ion loss process. The energetic fusion product ion loss process arises from a portion of energetic fusion product ions not transferring energy to the core plasma 10. This portion of the energetic fusion product ions escape the core plasma 10 and reach the periphery of the core plasma 10. The stochastic mantle 12 provides protection of the interior plasma-facing component 1 against the energetic fusion product ion loss process. The protection provided by the mantle plasma 13, includes the atoms and the molecules which reduce energy of the energetic fusion product ions exiting from the core plasma 10 through a friction process, globally protecting the interior plasma-facing component 1 from excessive local incident power density and damage.

[0101] 8) In a final variant of the invention, as illustrated in FIGS. 1, 2, 5 and 6, the magnetic fusion device 101 further includes an energetic fusion product ion loss process. The energetic fusion product ion loss process arises from a portion of energetic fusion product ions not transferring energy to the toroidal fusion core plasma 110. This portion of the energetic fusion product ions escape the toroidal fusion core plasma 110 and reach the periphery of the toroidal fusion core plasma 110. The stochastic mantle 12 provides protection of the interior plasma-facing component 1 against the energetic fusion product ion loss process. The protection provided by the mantle plasma 13, includes the atoms and the molecules which reduce energy of the energetic fusion product ions exiting from the toroidal fusion core plasma 110 through a friction process, globally protecting the interior plasma-facing components 1 from excessive local incident power density and damage.