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:
“If we admit a thing so extraordinary as the creation of this world, it should seem that we admit something strange, and odd, and new to human apprehension, beyond any other miracle whatsoever.”
—George Berkeley (1685–1753)
“The human spirit is itself the most wonderful fairy tale that can possibly be. What a magnificent world lies enclosed within our bosoms! No solar orbit hems it in, the inexhaustible wealth of the total visible creation is outweighed by its riches!”
—E.T.A.W. (Ernst Theodor Amadeus Wilhelm)
“The very austerity of the Brahmans is tempting to the devotional soul, as a more refined and nobler luxury. Wants so easily and gracefully satisfied seem like a more refined pleasure. Their conception of creation is peaceful as a dream.”
—Henry David Thoreau (1817–1862)