Instability of the Linearly Polarized Mode in Counterstreaming Electron-Ion Plasmas

Abstract

The instability of the linearly polarized mode propagating perpendicular to the magnetic field, considered previously for counterstreaming electron plasmas, is here studied for plasmas with ion streaming using the cold‐plasma equations. For two ion beams with velocities +u_i and −u_i in a neutralizing background of electrons, it is found that instability occurs when u_i>cΩ_i/ω_pi, with maximum growth rate (u_i²ω_pi²/c² − Ω_i²)^1/2, when Ω_i and ω_pi are, respectively, the ion cyclotron and plasma frequencies; c is the velocity of light. The case of two counterstreaming plasmas with both electron and ion streaming is also discussed.