The acceleration principle of an electron linear accelerator is mainly based on the acceleration effect of high-frequency electromagnetic fields on the electron beam.
Electronic linear accelerators typically consist of a vacuum accelerator tube, microwave power source, electron gun, focusing coil, and other related components.

1. Electron gun and electron beam generation:

The electron gun is the starting point of an electron linear accelerator, and its main function is to generate and emit high-intensity electron beams. An electron gun typically consists of a cathode, anode, and a beam focusing system. The cathode emits electrons after heating, the anode accelerates the electrons, and the beam focusing system is used to focus the electron beam into a certain beam current.

2. Accelerating Tube and High Frequency Electric Field:

The accelerator tube is the core component of an electron linear accelerator, consisting of a series of metal rings or electrodes that generate a high-frequency electric field through a high-voltage power source.
When the electron beam enters the accelerator tube, it will be accelerated under the action of a high-frequency electric field. The direction of the electric field is the same as the movement direction of the electron beam, so the electron beam will continuously gain energy and gradually increase its speed under the action of the electric field.

3. Traveling wave acceleration and standing wave acceleration:

Electronic linear accelerators can use either traveling wave acceleration or standing wave acceleration.
Traveling wave acceleration refers to the propagation of high-frequency electromagnetic fields generated by microwave power sources along the accelerator tube, interacting with electron beams to achieve acceleration. The electron beam is constantly accelerated and focused under the action of an electromagnetic field.
Standing wave acceleration refers to the formation of standing waves inside the accelerating tube, and the electron beam is accelerated in the standing wave field. The standing wave acceleration method usually involves periodically inserting a circular diaphragm with a central hole into the acceleration tube, relying on the reflection effect of the diaphragm to slow down the phase velocity of electromagnetic field propagation and achieve synchronous acceleration of electrons.

4. Focusing coils:

The focusing coil is used to constrain the electron beam and prevent its diffusion in space. The magnetic field generated by the focusing coil interacts with the charge of the electron beam, maintaining a stable trajectory of the electron beam during acceleration.

5. Functional modules:

The electronic linear accelerator also includes functional modules such as power drive system, frequency stabilization system, beam monitoring system, etc. These modules ensure the normal operation of the accelerator and monitor and control the electron beam.

6. Acceleration process:

The electron beam passes through a series of electrodes and magnets in an accelerator tube, and is subjected to high-frequency electric fields and focused magnetic fields, continuously accelerating and focusing. Finally, the electron beam leaves the accelerator tube at a speed close to the speed of light, reaching the required energy level.

Through the above principles, electron linear accelerators can achieve efficient acceleration of electron beams, providing high-energy electron beams for scientific research, medical and industrial fields.