THz Pulse Electron Acceleration Without Waveguides
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for accelerating electrons to relativistic velocities are inefficient, particularly for small electron charges and initial zero kinetic energy electrons, and existing technologies face limitations in energy transfer and synchronization, leading to suboptimal acceleration and energy distribution in electron bunches.
Innovation Solution
The method employs pairs of THz pulses propagating in opposite directions, focusing on the electron bunch to create a superimposed electromagnetic field that cancels magnetic fields and enhances electric field strength, allowing for efficient acceleration across multiple stages without waveguides, enabling the acceleration of electrons from zero initial kinetic energy to relativistic speeds with improved synchronization and energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If dielectric accelerators with laser beams are used to accelerate electrons, then relativistic electron velocities can be achieved, but the accelerator size in the micron range limits it to accelerating only a very small amount of charge at a time
Solution Approach 1:
The patent replaces the mechanical/dielectric accelerator structure with a purely electromagnetic field-based acceleration system using THz pulses. The acceleration occurs in free space without physical grids or dielectric structures, allowing large electron charges to be accelerated simultaneously while maintaining relativistic velocities.
Solution Approach 2:
The patent transitions from one-dimensional acceleration through micron-scale dielectric structures to three-dimensional acceleration in free space using focused THz pulse pairs. This dimensional expansion allows much larger quantities of electrons to be accelerated simultaneously without the spatial constraints of previous designs.
2Speed
If THz pulses are used to accelerate charged particles through optical crystal blocks, then acceleration can be achieved, but the destruction threshold of the crystal material limits the energy of applicable THz pulses from above
Solution Approach 1:
The patent extracts the acceleration function from the optical crystal blocks entirely, performing acceleration in free space using focused THz pulse pairs. This removes the destruction threshold limitation of crystal materials while maintaining the ability to apply high-energy THz pulses for efficient electron acceleration.
Solution Approach 2:
The patent introduces a free space interaction region as an intermediary between the THz pulse source and the electron beam. This intermediary allows the THz pulses to accelerate electrons without the harmful interaction with crystal lattice structures that limits pulse energy in previous designs.
3Force
If counterpropagating THz pulses are used to accelerate electrons, then the electric field strength can be enhanced, but the magnetic fields do not cancel and cause transverse displacement of electrons
Solution Approach 1:
The patent uses asymmetric positioning of the two counterpropagating THz pulses relative to the electron beam. By placing the pulses at specific asymmetric angles and positions, the magnetic field components that cause transverse displacement are minimized while the electric field components that accelerate the electrons are maximized and reinforced.
Solution Approach 2:
The patent optimizes the local field configuration at the specific interaction region where electrons are accelerated. The THz pulses are focused and positioned to create a local environment where electric field enhancement occurs precisely where needed for acceleration, while magnetic field effects are minimized through careful geometric arrangement.
4Speed
If electron acceleration is performed with THz pulses in existing arrangements, then some acceleration occurs, but the accelerating and decelerating forces are compensated and electron energy does not increase significantly
Solution Approach 1:
The patent applies the THz pulse pair in a specific temporal sequence where the first pulse prepares the electrons for acceleration and the second pulse delivers the primary accelerating force. This preliminary action ensures that electrons are in the optimal state to gain maximum energy from the accelerating field while minimizing decelerating effects.
Solution Approach 2:
The patent uses periodic THz pulse pairing where multiple pulse pairs can be applied in sequence. Each pulse pair provides a complete acceleration cycle, and the periodic application of these pairs allows cumulative energy gain while the timing and phase are controlled to ensure accelerating forces dominate over decelerating forces throughout the process.
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 energy and velocity of electron bunches, allowing for the acceleration of larger electric charges with reduced longitudinal spreading and improved monoenergetic behavior, enhancing the efficiency and applicability of electron acceleration.
Implementation Method 1
focusing on the electron bunch to create a superimposed electromagnetic field that cancels magnetic fields and enhances electric field strength
Implementation Method 2
allowing for efficient acceleration across multiple stages without waveguides, enabling the acceleration of electrons from zero initial kinetic energy to relativistic speeds
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3~4A
AI summary
The invention relates to a novel technique for the acceleration of electrons to relativistic energies. According to the technique, electrons (40) of low initial energy are generated by an electron source (17). At the location of the electrons, at least two THz pulses (10, 20) are provided synchronized to an instant of time of the electron generation. By superimposing electric fields of the at least two THz pulses, a non-steady resultant electric field is generated at the location of the electrons and the electrons are brought into interaction with the resultant electric field accordant to a temporal evolution of the electric field strengths of the THz pulses, thereby increasing electron energy, and thus, accelerating the electrons along a propagation path (30) to relativistic energies. Here, the provision of the THz pulses and the instant of time of the electron generation are synchronized to one another by providing, at the location of the electrons at the instant of time of the electron generation, each of the THz pulses by a THz pulse with an electric field of predetermined phase, said phase being the same for each THz pulse, and by generating the non-steady resultant electric field as an electric field with an electric field strength having a direction that represents an accelerating influence on the electrons.