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How are linear accelerators used in medicine and industry?

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Diagram of a linear proton resonance accelerator, or linac, showing protons entering from a source, passing through a series of labeled drift tubes powered by a radio-frequency source, and exiting as a beam through a cavity. — particle accelerator The accelerator is a large-diameter tube within which an electric field oscillates at a high radio frequency. Within the accelerator tube are smaller diameter metallic drift tubes, which are carefully sized and spaced to shield the protons from decelerating oscillations of the electric field. In the spaces between the drift tubes, the electric field is oriented properly to accelerate the protons in their direction of travel.

Linear accelerators are versatile instruments that impart energy to subatomic particles, serving critical roles in both medicine and industry.1

Medical Applications

In medicine, linear accelerators are the primary tools for external beam radiation therapy. By accelerating electrons or other charged particles, these machines generate high-energy beams—often in the megavoltage range—that can penetrate deep into the body to treat tumors. This technology allows for precise targeting, such as in intensity-modulated radiation therapy (IMRT), while minimizing damage to surrounding healthy tissue. Additionally, linear accelerators are used for the sterilization of disposable medical supplies, including syringes and blood transfusion kits.234

Industrial Applications

In industry, linear accelerators are utilized for radiation processing, which involves modifying or synthesizing materials using electron beams. Key industrial uses include:4
* Material Curing: Electron beams are used to cure paints, coatings, and rubber for automobile tires at room temperature, which is more energy-efficient than traditional heat-based methods.4
* Polymer Processing: Irradiation facilitates the cross-linking of polymers, essential for producing heat-shrinkable packaging and high-temperature insulation for wires and cables.4
* Food Preservation: Small doses of radiation inhibit sprouting and delay spoilage in food products, offering an energy-efficient alternative to refrigeration or canning.4
* Radiography: These machines are employed for industrial radiography to inspect materials and components.53