Rotating and Propagating LIB Stabilized by Self-Induced Magnetic Field

Abstract

Rotating motions of propagating LIB are analyzed in order to suppress the instability of mixed mode of the Kelvin-Helmholtz, tearing and sausage types by the action of a self-induced magnetic field in the axial direction. The beams are assumed to be charge-neutralized but not current-neutralized. The steady-state solutions of propagating LIB with rotations are numerically obtained first. Through the dispersion relation with respect to the ikonal type of perturbations which are added to the steady-state solutions, the growth rates of instabilities appearing in LIB are obtained. It is concluded that if the mean rotating velocity of LIB is comparable to the propagation velocity, in other words, if the induced magnetic field intensity in the axial direction is comparable to the magnetic field intensity in the azimuthal direction, the macro-instability disappears in the propagating ion beam.