الفهرس | Only 14 pages are availabe for public view |
Abstract A reductive perturbation theory has been applied to investigate solitary waves structure in an unmagnetized and a magnetized hot dusty plasma consisting of isothermal hot electron , nonisothermal (vortex like distribution ) ions and high negatively charged massive dust grains . ?The perturbation theory leads to a modified Korteweg de Vries (mKdV) equation. A nonisothermal ions distribution provides the possibility of coexistence of both rarefactive and compressive solitary waves , independent of the sign of the nonlinear coefficient in the mKdV equation . On the other hand , in case of a critical ion density , the reductive perturbation theory has been applied with a new time space stretching to give an evolution equation ; Korteweg de Vries (KdV) equation, describing the system in this situation . It has been shown that , at the critical ion density , if the sign of the nonlinear coefficient is positive (negative) there exist compressive (rarefactive) solitary waves . ?It is seen that , in both cases ( the mKdV equation and the KdV equation ) , the magnitude of the external magnetic field has no effect on the amplitude of the solitary waves but it affects on the width of the solitary waves . It is shown also that as the magnitude of the magnetic field increases the width of the solitary waves decreases. |