Multiphysics Couplings
Plasma Conductivity Coupling
The Plasma Conductivity Coupling multiphysics coupling node () computes the electrical conductivity of the plasma based on the cold plasma approximation. The electron density is provided by the Plasma or Plasma, Time Periodic interfaces and the and collision frequency can be provided by the Plasma or Plasma, Time Periodic interfaces or set by the user. The angular frequency is provided by the Magnetic Fields or Electromagnetic Waves, Frequency Domain interfaces.
Collision frequency specification
Select how to set the collision frequency from Specify collision frequency using — User defined, Electron mobility (the default), or Electron energy distribution function. The option Electron energy distribution function only exists for the Plasma interface.
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When User defined is selected enter values for the Effective collision frequency and the Field coefficient. The plasma conductivity is computed using these values and the electron density provided by the Plasma or Plasma, Time Periodic interfaces. For the Plasma, Time Periodic interface the electron density used in the plasma conductivity is period averaged.
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When Electron mobility is selected the momentum collision frequency used to computed the plasma conductivity is obtain from the mobility defined in the Plasma interface using
(6-17)
and for the Plasma, Time Periodic interface using
(6-18)
where is the period averaged electron mobility.
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The option Electron energy distribution function is only available when the options two-term approximation (linear), or Boltzmann equation, two-term approximation (quadratic) are selected from the property Electron energy distribution function. When using this option the effective collision frequency νeff and the field coefficient are automatically computed using:
(6-19)
(6-20)
where μr and μi are the real and imaginary parts of the mobility defined in Boltzmann Equation, Two-Term Approximation.
compute tensor plasma conductivity
If a static magnetic field is present, and the pressure is suitably low, it may be necessary to use a full tensor for the plasma conductivity. This can result is a nonlinear and anisotropic plasma conductivity, as is the case in electron cyclotron resonance. When Compute tensor plasma conductivity is active, enter a value for the Doppler broadening parameter. This can smooth resonance zones where the power deposition is focused over a very small region. The lower the value entered, the more smoothing occurs. More information can be found in the Resonance Zone section.
This option is not available for the Plasma, Time Periodic interface.
coupled interfaces
The selection for this multiphysics coupling is locked, and corresponds to the intersection of the Magnetic Fields or Electromagnetic Waves, Frequency Domain and Plasma or Plasma, Time Periodic interfaces specified in the Coupled Interfaces section.