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Linear accelerator

• Medical linear accelerators (linac) units are used in external beam radiation therapy to treat cancer.

• IT IS A THEREPATIC EQUIPMENT

• Linacs emit a well-defined beam of uniformly intense x-ray photon radiation of different energies, depending on the accelerator.

LINAC (schematic diagram)

components of Linear Accelerator

• Radio frequency Power source

• Modulator

• Electron Gun

• Accelerator guide

Working Principle:

▫ The modulator amplifies the AC power supply, rectifies it to DC power, and produces high-voltage DC pulses that are used to power the electron gun and RF power source.

▫ High-voltage cables electrically connect the electron gun and RF power source to the modulator, which can be located in the gantry.

▫ The electron gun injects electrons into the accelerator guide in pulses of the appropriate duration, velocity, and position to maximize acceleration.

▫ The RF power source, either a magnetron supplies high-frequency electromagnetic waves which accelerate the electrons injected from the electron gun down the accelerator guide.

A power supply Provides DC power to the modulator

Modulator

the magnetron

Deliver the pulses to the electron gun

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row

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the accelerator tube

or structure via a

waveguide systems.

elec

trons

Applications:

• linacs are used primarily to treat bone cancer and tumors of the head and neck.

• High energy linacs are used to treat deep tumors of the pelvis and thorax.

Thank you