Small amplitude dust ion–acoustic solitons including dust charge fluctuations in dusty plasma with regularized–<i>κ</i> distributed electrons

Abstract The small amplitude dust ion acoustic (DIA) solitons including the dust charge fluctuation in a dusty plasma with regularized– κ distributed electrons (RKDEs) has been studied from the reductive perturbation theory. The numerical results reveal that there only exists the soliton with velocity larger than the DIA velocity which is modified by the RKDEs and the dust charge fluctuation. And the polarity of soliton may be positive and negative. The negative soliton presences in a case with relatively small spectral index κ . For positive soliton, the amplitude of soliton increases with the decrease of cutoff parameter α and κ . Whereas, the amplitude of negative soliton varies in an inverse way. The reduction of the phase velocity of DIA wave (DIAW) for the presence of the dust charge fluctuation increases with the decrease of α and the electron concentration σ . But, it varies with κ non-monotonously. The effects of dust charge fluctuation on the width of DIA solitons is similar as the ones of the phase velocity of DIAW. Furthermore, dust charge fluctuations cause the amplitude of negative solitons to increase, and this effect diminishes as κ , σ and α increase. Whereas, the effect of dust charge fluctuations on the amplitude of positive solitons behaves inversely. The model is applied to interpret the observed electrostatic structures in Saturn’s magnetosphere, with particular discussion on the existence of non-Maxwellian electrons characterized by low κ -values.