The effects of nonadiabatic dust charge variation and ultraviolet irradiation on the modulational instability of dust ion acoustic waves

摘要

The effects of nonadiabatic dust charge fluctuation on the nonlinear propagation of the dust ion acoustic (DIA) waves in the dusty plasma with positively charged dust grains have been investigated. By using the reductive perturbation technique, a three-dimensional modified nonlinear Schr?dinger equation (mNLSE) governing the nonlinear envelope DIA waves was derived and the approximate solitary wave solution of the mNLSE was also obtained in the weak effect of nonadiabatic dust charge fluctuation limit, which shows that the amplitude of the DIA solitary wave exponentially decreases with time due to the collisionless dissipation caused by the nonadiabatic dust charge variation. The frequency, instability growth rate, and the critical modulational wave number of the small amplitude modulation are all dependent on photoelectron generated by ultraviolet irradiation and time due to the presence of nonadiabatic dust charge variation. The transverse perturbation plays an important role in the modulational instability region.