SOLITARY SOUND PULSES VIA ELECTRON-VORTEX DISTRIBUTION IN PARTIALLY-IONIZED PLASMAS

It is shown that nonlinear propagation of sound waves in partially ion ized collisional plasmas is governed by a modified Korteweg-de Vries ( mKdV) equation when the electron distribution function deviates from t he Boltzmann distribution. The mKdV equation admits a sharply localize d solitary sound pulse, the profile and width of which are: different from that which involves the Boltzmann electron number density respons e. Since the electron-vortex distribution induced solitary sound pulse s are more pronounced, it can easily be identified in partially ionize d plasmas.