Heavy-ion acceleration in a multi-ion-species plasma

The heavy-ion acceleration by a magnetosonic wave in a multi-ion species plasma is discussed. In the plasma of two ion species, the magnetosonic wave splits into two modes (low-frequency and high-frequency modes). KdV equations are derived for these modes. In case of normal propagation, the width of the solitary wave is ∼c/ωpi for low-frequency mode and ∼c/ωpe for high-frequency mode. In a hydrogen plasma including a small amount of He, C, N and Fe, the magnetosonic shock wave reflects a part of hydrogen ions and accelerates heavy ions passing through the wave. All heavy ions have the same terminal velocity. (T. Ikehata)