Some properties of large-amplitude, negative-potential solitary waves in a three-component plasma

Large-amplitude, negative-potential solitary waves in a plasma containing positive and negative, cold, collisionless ions and isothermal electrons are studied computationally and analytically. When their amplitude and speed are large, both speed and width are proportional to the square root of amplitude. That is, amplitude is proportional to speed squared, while width increases directly with speed. Approximate expressions relating these quantities are derived.