A charged particle accelerator for converting electrical potential energy into magnetic orbital angular momentum

Background

The field of advanced particle acceleration is critical for applications like plasma heating in nuclear fusion reactors and precision beam lithography. In these domains, there is a profound need to precisely control the kinetic energy and trajectory of charged particles. Fusion reactors require highly efficient methods to heat plasmas while maintaining strict magnetic confinement to sustain reactions. Similarly, next-generation semiconductor manufacturing demands lithographic techniques capable of making ultra-shallow, precise modifications to material surfaces. Consequently, industries require sophisticated beam technologies that deliver highly energetic particles with specialized momentum profiles.

Despite these needs, current approaches suffer from significant limitations because they primarily generate linear momentum. In fusion applications, conventional neutral beam injectors introduce particles with low magnetic orbital angular momentum. This results in weak magnetic confinement within the plasma, drastically reducing heating efficiency. In beam lithography, traditional accelerators produce beams that strike surfaces with high normal momentum. This perpendicular impact transfers excessive force deep into the substrate, preventing the shallow, tangential impingement required for delicate surface cuts. Furthermore, existing systems struggle to filter out unwanted parallel kinetic energy, leading to inefficient particle trajectories and poor overall beam control.

Technology

The disclosed technology is a particle acceleration system that directly converts electrical potential energy into magnetic orbital angular momentum (MOAM). Charged particles originate in a low-magnetic-field region, undergo focusing via an Einzel lens, and enter a reversed transverse drift filter. Inside, voltage-controlled electrodes and shaped magnetic field gradients generate crossed electric and magnetic fields. By balancing ExB drift against gradient-B drift, the system guides particles along trajectories where kinetic energy increases primarily in the transverse direction. To maintain this transverse dominance, a three-channel geometry utilizes specialized potential wells to systematically trap and drain unwanted parallel kinetic energy.

This solution is fundamentally differentiated from conventional neutral beam injectors, which rely on imparting high linear momentum. By maximizing MOAM instead, the system produces highly energetic, strongly magnetically confined particle beams. This superior magnetic confinement significantly improves heating efficiency when injecting particles into plasmas for fusion reactors. Additionally, the high MOAM causes particles to impinge on surfaces at nearly tangential angles, enabling precise, shallow-angle beam lithography without transferring significant normal momentum to the substrate. The precise control over transverse energy, even in low magnetic fields, makes this architecture uniquely suited for advanced directional momentum transfer, space propulsion, and fundamental physics applications.

Benefits

• Enhances plasma heating efficiency in fusion reactors by producing highly energetic, strongly magnetically confined particle beams.
• Enables precise, shallow-angle beam lithography by allowing particles to impinge on surfaces tangentially without significant normal momentum transfer.
• Facilitates directional momentum transfer, offering potential applications in novel space propulsion systems and mechanical angular momentum generation.
• Provides highly precise control over particle kinetic energy and trajectories, even in low magnetic field environments, using a specialized three-channel filter geometry.
• Ensures robust and reliable operation with high tolerance to physical imperfections and electrode misalignment through adaptive voltage control methods.
• Advances fundamental physics research, such as cosmic neutrino background detection, by enabling the precise transport and measurement of low-energy particles.

Applications

• Fusion reactor plasma heating
• Shallow-angle beam lithography
• Spacecraft directional momentum propulsion
• Mechanical angular momentum generation
• Tangential surface material processing

Additional info

This technology accelerates charged particles by converting electrical potential energy into magnetic orbital angular momentum rather than linear momentum. Utilizing an Einzel lens and reversed transverse drift filter, the system balances ExB and gradient-B drifts. A three-channel geometry drains parallel kinetic energy, ensuring transverse dominance. The resulting energetic, magnetically confined beams enable fusion plasma heating, shallow-angle lithography, and directional momentum transfer.