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:
“A fact is the end or last issue of spirit. The visible creation is the terminus or the circumference of the invisible world.”
—Ralph Waldo Emerson (1803–1882)
“The creation of a world view is the work of a generation rather than of an individual, but we each of us, for better or for worse, add our brick to the edifice.”
—John Dos Passos (1896–1970)
“For me, the principal fact of life is the free mind. For good and evil, man is a free creative spirit. This produces the very queer world we live in, a world in continuous creation and therefore continuous change and insecurity. A perpetually new and lively world, but a dangerous one, full of tragedy and injustice. A world in everlasting conflict between the new idea and the old allegiances, new arts and new inventions against the old establishment.”
—Joyce Cary (1888–1957)