Encyclopedia > Space charge

  Article Content

Space charge

When a metal object is placed in a vacuum, and is heated to incandescence, the energy is sufficient to cause electrons to "boil" away from the surface atoms and surround the metal object in a cloud of free electrons. The resulting cloud is negatively charged, and can be attracted to any nearby positively charged object, thus producing an electrical current which passes through the vacuum.

This effect was first observed by Thomas Edison in light bulb filaments[?], where it is sometimes called the Edison effect[?].

See also



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Ocean Beach, New York

... 61 households out of which 29.5% have children under the age of 18 living with them, 45.9% are married couples living together, 8.2% have a female householder with no ...

 
 
 
This page was created in 40.2 ms