Equations · equation
Plasma Frequency
Plasma Physics · 1929
- Equation
- ω_p = √(n·e² / (ε₀·mₑ))
- Field
- Plasma Physics
- Named After
- Lewi Tonks · Irving Langmuir
- Symbols
- ω_p natural sloshing frequency of the electrons · n electron density · e electron charge · ε₀ permittivity of free space · mₑ electron mass
- Year
- 1929
Significance
Displace a plasma's electrons and they slosh back at this frequency — waves below it bounce off, waves above pass through. It's why shortwave radio skips off the ionosphere to cross oceans, and why metals (a plasma of conduction electrons) are shiny mirrors to visible light.
Referenced by
constant
element
equation
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