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:
“Humility like darkness reveals the heavenly lights. The shadows of poverty and meanness gather around us, “and lo! creation widens to our view.””
—Henry David Thoreau (1817–1862)
“There have been heroes for whom this world seemed expressly prepared, as if creation had at last succeeded; whose daily life was the stuff of which our dreams are made, and whose presence enhanced the beauty and ampleness of Nature herself.”
—Henry David Thoreau (1817–1862)
“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)