Arbitrary amplitude dust acoustic solitary structures have been investigated in a four component multi-species plasma consisting of negatively charged dust grains, nonthermal ions, isothermally distributed electrons and positrons including the effect of dust temperature. We have used the Sagdeev pseudo-potential method to discuss the arbitrary amplitude steady state dust acoustic solitary structures in the present plasma system. We have designed a computational scheme to draw the existence domains of different dust acoustic solitary structures. We have observed only negative potential solitary waves for isothermal ions. But for strong nonthermality of ions the system supports positive potential solitary waves, positive potential double layers and coexistence of solitary waves of both polarities. The positive potential solitary waves are restricted by the positive potential double layers but negative potential double layer has not been found for any parameter regime. The system does not support dust acoustic supersoliton of any polarity. The concentration of positrons plays an important role in the formation of positive potential double layers. Finally, the phase portraits of the dynamical system have been presented to confirm the existence of different dust acoustic solitary structures.
Dust ion acoustic solitary structures in nonthermal dusty plasma
研究了由负电荷尘埃粒子、绝热正离子和非热电子组成的非磁化非热等离子体中尘埃离子声孤波结构。对于等温电子，目前的等离子体系统不支持任何双电层解决方案，而对于非热电子，负电位双电层开始出现时，非热参数超过一个临界值。然而，这种双层解并不能限制本系统所有负势孤立波的出现。结果表明，两种不同类型的负势孤波的出现受到M_c<M<M_D whereas the second type solitary wave exists for all M>_D的限制，其中M_c为马赫数M的下限，M_D（>M_c）为负势双层对应的马赫数。在M=M_D-ε_1和M=M_D+ε_2处，观察到孤波负势振幅之间的有限跳跃，其中0<ε_1<M_D-M_c和ε_2>0。提出了双电层存在的解析理论。还提供了一个数值方案，以找出存在双层解时的马赫数值以及该双层的振幅。虽然两极孤波共存的发生受到M_c<M <= M_max的限制，但当M>M_max时，仍然只存在负势孤波，这里M_max是只存在正势孤波时M的上界。发现了反映能量积分孤立子结构性质的不同组分参数空间，这些解空间为孤立子结构的形成提供了新的结果和物理思想。
Higher order stability of dust ion acoustic solitary wave solution described by the KP equation in a collisionless unmagnetized nonthermal plasma in presence of isothermal positrons
Effect of Landau damping on ion acoustic solitary waves in a multi-species collisionless unmagnetized plasma consisting of nonthermal and isothermal electrons
Damped dust-ion-acoustic solitons in collisional magnetized nonthermal plasmas
研究了一个多粒子磁化碰撞非热等离子体系统中的耗散尘埃-离子-声（DIA）孤子模\textbf{theoretically and parametrically}的特性。该系统中包含惯性离子、服从非热$κ-$分布的非惯性电子和不动尘埃粒子。静电孤波模与低频耗散尘埃离子声孤波（DIASW）有关。考虑了离子与中性粒子的碰撞效应，研究了离子与中性粒子碰撞效应对耗散型DIASW动力学的影响。空间和实验室中的等离子体介质大多远离热平衡，粒子分布更符合$κ-$非热分布，而非热麦克斯韦分布。采用约化摄动方法导出阻尼KdV（dKdV）方程，并利用切双曲方法导出dKdV方程的孤波解，分析其基本特征（振幅、宽度、速度、时间演化等）.分散的潜水员的传播性质，也耗散DIASW的基本特征被认为是影响显着由于等离子体配置参数的变化，也由于在所考虑的等离子体系统中的超热指数$κ$的变化。这项研究的结果的含义可能是有用的，更好地了解静电本地化的扰动，在离子长度和时间尺度，在空间和实验尘埃等离子体，其中存在的过量高能电子和离子中性碰撞阻尼是负责。
Dust-ion-acoustic damped solitary waves and shocks in laboratory and Saturn's E-ring magnetized nonthermal dusty plasmas with anisotropic ion pressure and dust-charge fluctuation
