Collision-induced instability in a magneto-active plasma

The dispersion laws for the waves propagating in a magnetoactive plasma are obtained, using the Boltzmann equation with a collision term representative of isotropic, recoilless, elastic, binary scattering of the electrons. In the work, the two cases (I) M; k||B_o and (II); kiB_o are studied, where k and B_o are the wave vector and the uniform external magnetic field. Assuming a δ-function for the velocity distribution function the dispersion laws for a long wavelength limit are classified as follows : A……ω(ω+iv)²=ω_p²(ω+iv-i V/3‧dv/dV) B……ω(ω±ω_c+iv)²=ω_p²(ω±ω_c+iv-i V/3‧dv/dV) where ω_c, ω_p and v are the cyclotron, the plasma, the collision frequency respectively. After some calculations under the assumption v (V) =const×V^h, it is found that the initial disturbance grows for h>3 and Im (ω) attains its maximum value at Re (ω) =ω_c. (author)