Magnetosonic wave

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A magnetosonic wave is a longitudinal wave[1] of ions (and electrons) in a magnetized plasma propagating perpendicular to the stationary magnetic field. The wave is dispersionless with a phase velocity ω/k given by

\frac{\omega^2}{k^2}=c^2\,\frac{v_s^2+v_A^2}{c^2+v_A^2},

where vs is the speed of the ion acoustic wave, vA is the speed of the Alfvén wave, and c is the speed of light in vacuum.

In the limit of low magnetic field (vA→0), the wave turns into an ordinary ion acoustic wave. In the limit of low temperature (vs→0), the wave becomes a modified Alfvén wave. Because the phase velocity of the magnetosonic mode is almost always larger than vA, the magnetosonic wave is often called the "fast" hydromagnetic wave.

[edit] References

  1. ^ The wave is longitudinal in the perturbation of the fluid velocity, although the perturbation of the magnetic field is transverse. See Schmidt, Physics of High Temperature Plasmas, p.101.

[edit] See also

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