Thermionic emission
| Advanced search |
- About 3 results found and you can help!
 Closeup of the filament on a low pressure mercury gas discharge lamp showing white thermionic emission mix coating on the central portion of the coil. Typically made of a mixture of barium, strontium and calcium oxides, the coating is sputtered away through normal use, often eventually resulting in lamp failure. |
Thermionic emission is the heat-induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the binding potential, also known as work function of the metal. The charge carriers can be electrons or ions, and in older literature are sometimes referred to as "thermions". After emission, a charge will initially be left behind in the emitting region that is equal in magnitude and opposite in sign to the total charge emitted. But if the emitter is connected to a battery, then this charge left behind will be neutralized by charge supplied by the battery, as the emitted charge carriers move away from the emitter, and finally the emitter will be in the same state as it was before emission. The thermionic emission of electrons is also known as thermal electron emission.
- See also: Wikipedia
- Related: Cathode, Hot cathode, Cold cathode, Space charge, Thermionic converter, Thermoelectric effect, Vacuum tube, Work function, X-ray tube
| How vacuum tubes really work with a section on the... How vacuum tubes really work with a section on thermionic emission, with equations www.john-a-harper.com/tubes201/ - Web |
| Owen Richardson's Nobel lecture on thermionics Owen Richardson's Nobel lecture on thermionics www.nobel.se/physics/laureates/1928/richardson-lecture.pdf - Web |
| Derivations of thermionic emission equations from ... Derivations of thermionic emission equations from an undergraduate lab www.physics.csbsju.edu/lab/thermionic.pdf - Web |
Average relevance
