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Electron-beam processing involves irradiation (treatment) of products using a high-energy electron-beam accelerator. Electron-beam accelerators utilize an on-off technology, with a common design being similar to that of a cathode ray television. Electron-beam processing is used in industry primarily for three product modifications:
Research in this area has focused on the three most common sources of radiation used for these applications, including gamma, electron beam, and x-ray radiation. [17] The mechanisms of radiation damage are different for polymers and metals, since dislocations and grain boundaries do not have real significance in a polymer.
Very high energies from electron beams from particle accelerators, reaching tens of megaelectronvolts, can be deeply penetrating. Conversely, megavolt-scale beams can deposit their energy deeper with less damage to the dermis; modern radiotherapy electron beam accelerators take advantage of this.
Electron beam therapy is used in the treatment of superficial tumors like cancer of skin regions, or total skin (e.g. mycosis fungoides), diseases of the limbs (e.g. melanoma and lymphoma), nodal irradiation, and it may also be used to boost the radiation dose to the surgical bed after mastectomy or lumpectomy.
Electron-beam machining is a process in which high-velocity electrons are concentrated into a narrow beam with a very high planar power density. The beam cross-section is then focused and directed toward the work piece, creating heat and vaporizing the material. Electron-beam machining can be used to accurately cut or bore a wide variety of metals.
The beam passed through the back of his head, the occipital and temporal lobes of his brain, the left middle ear, and out through the left-hand side of his nose. The exposed parts of his head received a local dose of 200,000 to 300,000 roentgens (2,000 to 3,000 Sieverts ). [ 3 ]
External beam radiation therapy (EBRT) is a form of radiotherapy that utilizes a high-energy collimated beam of ionizing radiation, from a source outside the body, to target and kill cancer cells. A radiotherapy beam is composed of particles which travel in a consistent direction; each radiotherapy beam consists of one type of particle intended ...
The electron beam current required to produce the X-rays is about 100 times greater than that used for electron therapy. [6] Turntable rotation. The patient is placed on a fixed stretcher. Above them is a turntable to which the components that modify the electron beam are fixed.