Lower hybrid oscillation

Lower hybrid oscillation

A lower hybrid oscillation is a longitudinal oscillation of ions and electrons in a magnetized plasma. The direction of propagation must be very nearly perpendicular to the stationary magnetic field, within about √("m"e/"m"i) radians. Otherwise the electrons can move along the field lines fast enough to shield the oscillations in potential, in which case an electrostatic ion cyclotron wave results. The frequency of oscillation is:omega = sqrt{ Omega_comega_c},where Ωc is the ion cyclotron frequency and ωc is the electron cyclotron frequency. This is the lower hybrid frequency, so called because it is a "hybrid", or mixture, of two frequencies. There are also an upper hybrid frequency and upper hybrid oscillation. The lower hybrid oscillation is unusual in that the ion and electron masses play an equally important role. This mode is relatively unimportant in practice because the necessary precise orientation relative to the magnetic field is seldom achieved. Exceptions are the use of lower hybrid waves to heat fusion plasmas and the lower hybrid drift instability, which was thought to be an important determinant of transport in the Field-Reversed Configuration (but was not found experimentally).

See also

* Electrostatic ion cyclotron wave
* Waves in plasmas
* Ion acoustic wave
* Upper hybrid oscillation

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Upper hybrid oscillation — An upper hybrid oscillation is a mode of oscillation of a magnetized plasma. It consists of a longitudinal motion of the electrons perpendicular to the magnetic field with the dispersion relation:omega^2 = omega {pe}^2 + omega {ce}^2 + 3 k^2 v… …   Wikipedia

  • Electrostatic ion cyclotron wave — An electrostatic ion cyclotron wave is a longitudinal oscillation of the ions (and electrons) in a magnetized plasma, propagating nearly (but not exactly) perpendicular to the magnetic field. The angle (in radians) between the direction of… …   Wikipedia

  • Boltzmann relation — In a plasma, the Boltzmann relation connects the electron density n e to the plasma potential phi;pl as follows:: n e = n 0 exp(e phi;pl/ k B T e)The reference for the potential is taken to be a position where the electron density is n 0.It can… …   Wikipedia

  • Waves in plasmas — are an interconnected set of particles and fields which propagates in a periodically repeating fashion. A plasma is a quasineutral, electrically conductive fluid. In the simplest case, it is composed of electrons and a single species of positive… …   Wikipedia

  • Plasma scaling — The parameters of plasmas, including their spatial and temporal extent, vary by many orders of magnitude. Nevertheless, there are significant similarities in the behaviors of apparently disparate plasmas. It is not only of theoretical interest to …   Wikipedia

  • Electrodeless plasma thruster — The electrodeless plasma thruster is a spacecraft propulsion engine. It was created by Mr. Gregory Emsellem based on technology developed by French Atomic Energy Commission scientist Dr Richard Geller and Dr. Terenzio Consoli, for high speed… …   Wikipedia

  • Rocket engine — RS 68 being tested at NASA s Stennis Space Center. The nearly transparent exhaust is due to this engine s exhaust being mostly superheated steam (water vapor from its propellants, hydrogen and oxygen) …   Wikipedia

  • Electronic amplifier — A practical amplifier circuit An electronic amplifier is a device for increasing the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In… …   Wikipedia

  • United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …   Universalium

  • Operational amplifier — A Signetics μa741 operational amplifier, one of the most successful op amps. An operational amplifier ( op amp ) is a DC coupled high gain electronic voltage amplifier with a differential input and, usually, a single ended output.[1] An op amp… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”