Nonlinear plasma waves with steady-state d.c. current

Using a low-frequency, low-β model of a magnetized plasma, several nonlinear waves are studied. All the waves share the property that they have a self- consistent time-averaged current in the steady state. The first wave is a one- dimensional solitary wave that propagates obliquely to a static magnetic field. The wave magnetic field has a kink structure, which results in the production of the time-averaged current. A two-dimensional wave that propagates parallel to the background magnetic field is also discussed. This is a forced wave, requiring an antenna structure to support it in the steady state. The characteristics of the two-dimensional wave are dependent upon the wave speed, which in turn is determined by the speed of the travelling wave on the external antenna.