Editing Plasma oscillation (section)

{{Short description|Rapid oscillations of electron density}}
{{about|a specific type of plasma wave|plasma waves in general|Waves in plasmas}}
'''Plasma oscillations''', also known as '''Langmuir waves''' (after [[Irving Langmuir]]), are rapid oscillations of the [[electron density]] in conducting media such as [[Plasma (physics)|plasmas]] or [[metal]]s in the [[ultraviolet]] region. The oscillations can be described as an instability in the [[Drude model#AC field|dielectric function of a free electron gas]]. The frequency depends only weakly on the wavelength of the oscillation. The [[quasiparticle]] resulting from the [[Quantization (physics)|quantization]] of these oscillations is the ''[[plasmon]]''.

Langmuir waves were discovered by American [[physicist]]s [[Irving Langmuir]] and [[Lewi Tonks]] in the 1920s.<ref>{{cite journal |url=http://www.columbia.edu/~mem4/ap6101/Tonks_Langmuir_PR29.pdf |journal=Physical Review |year=1929 |volume=33 |issue=8 |pages=195–210 |title=Oscillations in ionized gases |first1=Lewi |last1=Tonks |first2=Irving |last2=Langmuir|bibcode=1929PhRv...33..195T |doi=10.1103/PhysRev.33.195 |pmc=1085653 }}</ref>  They are parallel in form to [[Jeans instability]] waves, which are caused by gravitational instabilities in a static medium.