Medical accelerator, a particle accelerator device used in biomedical applications for radiation therapy of tumors. According to the different types of accelerating particles, the shape of the accelerating electric field, and the different orbits followed by the particle acceleration process, accelerators are classified into various types. At present, electron linear accelerators are commonly used in radiation therapy.

Electron linear accelerator utilizes high-energy electrons with a certain energy (sub light speed) to interact with the microwave electric field of high-power microwaves, thereby obtaining higher energy. At this point, the speed of electrons does not increase significantly, mainly due to the continuous increase in mass (Einstein’s theory of relativity).

Direct electron extraction can be used for electron beam therapy.

Electron impact on heavy metal targets produces bremsstrahlung radiation, emitting X-rays for X-ray therapy. (The principle is similar to that of an X-ray machine, where the accelerator uses a transmission target.)

A simple electronic linear accelerator should at least include an acceleration site (accelerator tube), a high-power microwave source and waveguide system, a control system, radiation equalization, and protection system.

Medical linear accelerators are divided into two categories based on the characteristics of microwave transmission: traveling wave and standing wave. Their basic structures and systems include electron guns, microwave power sources (magnetrons or klystrons), waveguides [isolators, RF (radio frequency microwave source) monitors, phase shifters, RF absorption loads, RF windows, etc.], DC DC power supplies (radio frequency generators, pulse modulators, electron gun emission delay circuits, etc.), vacuum systems [vacuum pumps (titanium pumps)] The servo system (focusing coil, centering coil), deflection system (deflection chamber, deflection magnet), dose monitoring system, leveling system, field formation system, etc. are installed at the treatment head, fixed frame, rotating frame, treatment bed, control console, etc.