Self-Focusing of Transverse Waves in a Magnetoplasma

The self-focusing of the transverse waves (comprising the whistler, Alfvénic and electromagnetic modes) propagating along an applied magnetic field in a plasma of finite temperature is discussed. The method of stretching which has been used by Taniuti and Washimi 5) is applied. It is shown that behaviours of the wave amplitude are described by the nonlinear Schrödinger equation and that the threshold power for the self-focusing becomes very small not only at the special frequency for the whistler wave which was already obtained in the previous paper 5) but also at a frequency for the Alfvén wave. The expression of the coefficient of the nonlinear term of the nonlinear Schrödinger equation is revised.