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 everything which is not the involuntary result of fleeting emotion but the creation of time and will, any marriage, happy or unhappy, is infinitely more interesting than any romance, however passionate.”
—W.H. (Wystan Hugh)
“Today, each artist must undertake to invent himself, a lifelong act of creation that constitutes the essential content of the artist’s work. The meaning of art in our time flows from this function of self-creation. Art is the laboratory for making new men.”
—Harold Rosenberg (1906–1978)
“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)