Editing Electron cyclotron resonance (section)

== In plasma physics ==
An ionized [[Plasma (physics)|plasma]] may be efficiently produced or heated by superimposing a static [[magnetic field]] and a high-frequency [[electromagnetic field]] at the electron cyclotron [[resonance]] frequency. In the toroidal magnetic fields used in [[magnetic fusion energy]] research, the magnetic field decreases with the major radius, so the location of the power deposition can be controlled within about a centimetre. Furthermore, the heating power can be rapidly modulated and is deposited directly into the electrons. These properties make electron cyclotron heating a very valuable research tool for energy transport studies. In addition to heating, electron cyclotron waves can be used to drive current. The inverse process of [[Cyclotron radiation|electron cyclotron emission]] can be used as a [[Plasma diagnostics|diagnostic]] of the radial electron temperature profile.
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| [[File:Cyclotron-Resonance-Motion Linearly-Pol-Fields Freq-1.0 Efield-1.0 fps-20 Image-Res-100 Image-Size-610x610.gif |thumb|400px |Example of cyclotron resonance between a charged particle and linearly polarized electric field (shown in green). The position vs. time (top panel) is shown as a red trace and the velocity vs. time (bottom panel) is shown as a blue trace.  The background magnetic field is directed out towards the observer.  Note that the circularly polarized example below assumes there is no Lorentz force due to the wave magnetic field acting on the charged particle. This is equivalent to saying that the charged particle's velocity orthogonal to the wave magnetic field is zero.]]
| [[File:Cyclotron-Resonance-Motion Circularly-Pol-Fields Freq-1.0 Efield-1.0 fps-20 Image-Res-100 Image-Size-610x610.gif |thumb|400px  |Example of cyclotron resonance between a charged particle and circularly polarized electric field (shown in green). The position vs. time (top panel) is shown as a red trace and the velocity vs. time (bottom panel) is shown as a blue trace.  The background magnetic field is directed out towards the observer.  Note that the circularly polarized example below assumes there is no Lorentz force due to the wave magnetic field acting on the charged particle. This is equivalent to saying that the charged particle's velocity orthogonal to the wave magnetic field is zero.]]
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