Evolution of nonlinear dust-ion-acoustic waves in an inhomogeneous plasma

The propagation of nonlinear dust-ion-acoustic waves in an inhomogeneous dusty plasma is studied. At small but finite amplitudes, the wave evolution is governed by a modified Korteweg-deVries Burgers equation, whose coefficients are space dependent. The properties of the evolution equation are analyzed and the behavior of the corresponding shock and soliton solutions is numerically studied. If dust-charge perturbation is neglected, there exists a zero-nonlinearity point where the coefficient of the nonlinear term changes from negative to positive. At that point the nonlinear wave also undergoes structural deformation. If the dust-charge perturbation is taken into account, the zero-nonlinearity point may not appear and the soliton or shock wave will retain its form during the propagation. (c) 2006 American Institute of Physics.