Propagation of dust acoustic waves in a dusty plasma in the presence of ion nonthermality and background nonextensivity

摘要

The concept of ion nonthermality is generalized within the theoretical framework of the Tsallis thermostatistics. In this connection, a physically meaningful ion distribution function is outlined. In this communication, we have investigated solitary dust acoustic wave propagation in a charge varying dusty plasma in the presence of ion nonthermality and background nonextensivity. The correct non-Maxwellian ion charging current is derived based on the orbit-limited motion theory. Under grain-current balance, the variable dust charge is expressed in terms of the Lambert function. It is found that nonthermality and its nonextensive nature may act concurrently and influence the restoring force and hence the soliton profile.