High-Energy Plasma Generation With Low-Energy Neutral Beams
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Solution Overview
Problem
Generating high-energy plasmas for nuclear fusion using magnetic mirror confinement and neutral beam injection is difficult and costly due to the challenges of efficiently transferring radiofrequency energy to fast ions, requiring high-energy neutral beams that are not practical for net fusion energy generation.
Innovation Solution
A low-energy neutral beam is injected into a magnetic mirror confinement system, with its energy boosted within the containment volume using a radiofrequency electrical field tuned to a harmonic of the cyclotron frequency at a well-defined turning point, preferentially energizing fast ions for fusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a high-energy neutral beam is used to maintain fusion output in a magnetic mirror confinement system, then fusion energy output is sufficient, but the system becomes difficult and costly from an energy standpoint and is not practical for net fusion energy generation
Solution Approach 1:
The patent applies preliminary action by first injecting low-energy neutral beam particles into the magnetic mirror confinement system, then subsequently accelerating them to fusion energies using radiofrequency electromagnetic fields. This two-stage approach allows the system to avoid the immediate energy cost of generating high-energy neutral beams while still achieving the necessary fusion conditions.
Solution Approach 2:
The patent replaces the mechanical approach of directly accelerating neutral beams to high energies with an electromagnetic field-based acceleration method. Radiofrequency electromagnetic fields are used to accelerate the ionized particles to fusion energies, substituting the need for high-energy neutral beam generation equipment with a more efficient electromagnetic acceleration system.
2Use of energy by moving object
If a low-energy neutral beam is injected into the magnetic containment volume, then the energy cost is reduced, but the neutral beam particles lack sufficient energy to produce significant fusion directly
Solution Approach 1:
The patent ensures continuity of useful action by maintaining the neutral beam injection continuously and then using radiofrequency fields to accelerate the particles to fusion energies within the confinement volume. This continuous process ensures that low-energy particles are systematically converted to high-energy fusion-producing particles without interruption.
Solution Approach 2:
The patent introduces radiofrequency electromagnetic fields as an intermediary mechanism between the low-energy neutral beam injection and the high-energy fusion process. These electromagnetic fields serve as the mediator that transfers energy to the ionized particles, accelerating them to the necessary fusion energies without requiring direct high-energy beam injection.
3Power
If radiofrequency energy is transferred to fast ions in the plasma, then ion energy is boosted for fusion, but it is difficult to preferentially transfer energy to fast-neutral beam ions rather than thermal ions
Solution Approach 1:
The patent applies local quality by creating a spatially localized region where radiofrequency energy transfer is most effective. By carefully selecting the pitch angle and energy of the neutral beam, the patent creates a well-defined turning point region where fast ions spend more time, allowing preferential energy transfer to these ions rather than thermal ions throughout the entire plasma volume.
Solution Approach 2:
The patent uses dynamics by exploiting the time-varying nature of particle trajectories in the magnetic mirror confinement system. Fast ions with specific pitch angles follow dynamic trajectories that include turning points where they spend extended time, allowing resonant radiofrequency fields to preferentially transfer energy to these moving particles rather than stationary or slowly moving thermal ions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly increases the efficiency of plasma ion energy boosting, allowing for higher plasma densities and flux rates with lower energy neutral beams, enhancing fusion output and enabling applications such as transmutation and power generation.
Implementation Method 1
High-temperature plasmas can be confined away from a physical container and avoiding damage to the container and possible plasma quenching, by a magnetic mirror confinement system. Such confinement systems may provide an axial magnetic field extending between two ends at which the magnetic flux lines converge. Plasma ions moving within this axial magnetic field spiral along the flux lines at the local cyclotron frequency and are 'reflected' by an axial component of magnetic force acting on the spiraling ions.
Implementation Method 2
A radiofrequency generator can then be used to produce an electrical field to accelerate the beam-sourced ions to an energy sufficient for fusion of the plasma ions. Tuning the radiofrequency waves to a multiple (i.e., a harmonic) of the cyclotron frequency at the turning point, preferentially energizes these neutral beam injected ions to fusion levels
Implementation Method 3
The neutral particles of the neutral beam are ionized, that is, split into plasma ions and electrons
Data Source
AI summary
An apparatus for generating a highly energetic plasma employs a low-energy neutral beam injected into a magnetically contained mirror plasma to produce plasma ions boosted in energy to fusion levels by a coordinated radiofrequency field.