Creation
Charged particles such as electrons, positrons, and protons may be separated from their common surrounding. This can be accomplished by e.g. thermionic emission or arc discharge. The following devices are commonly used as sources for particle beams:
- ion source
- cathode ray tube, or more specifically in one of its parts called electron gun. This is also part of traditional television and computer screens.
- photocathodes may also be built in as a part of an electron gun, using the photoelectric effect to separate particles from their substrate.
- Neutron beams may be created by energetic proton beams which impact on a target, e.g. of beryllium material. (see article Particle therapy).
Read more about this topic: Particle Beam
Famous quotes containing the word creation:
“Like witches they flew along rows
Keeping creation at ease;
With a tendril for needle
They sewed up the air with a stem;”
—Theodore Roethke (1908–1963)
“One of the necessary qualifications of an efficient business man in these days of industrial literature seems to be the ability to write, in clear and idiomatic English, a 1,000-word story on how efficient he is and how he got that way.... It seems that the entire business world were devoting its working hours to the creation of a school of introspective literature.”
—Robert Benchley (1889–1945)