This paper investigates the features of the nonlinear kinetic Alfvén waves (KAWs) in a magnetized bi-ion plasma. In such a plasma model, a general Sagdeev equation can be obtained for different ranges of the plasma parameter α ≡ β/2Q (where β is the pressure ratio of the thermal to magnetic and Q is the mass ratio of electrons to protons). The analytical results show that the nonlinear dispersion curve of the KAWs is divided into two branches, and the wave phase speed decreases with more heavy ions. The numerical results indicate that both hump and dip density solitons, whose width and amplitude are affected by heavy ions, can possibly coexist in such bi-ion plasmas.
本文研究了磁化双离子等离子体中非线性动力学阿尔芬波（KAWs）的特征。在此类等离子体模型中，针对等离子体参数α ≡ β/2Q（其中β为热压与磁压之比，Q为电子与离子的质量比）的不同取值范围，可得到一般的萨格德夫方程。解析结果表明，非线性动力学阿尔芬波的色散曲线分为两支，且波相速度随重离子含量的增加而降低。数值结果进一步表明，在该类双离子等离子体中，凸形和凹形密度孤子均可能存在，其宽度和振幅受重离子影响。