Instabilities of the Whistler Mode in the Magnetosphere

248-253The nature of the convective instability has been investigated for whistler wave propagation at frequencies less than and close to the cyclotron frequency for an anisotropic and loss cone velocity distribution for the electrons. The dispersion equation has been solved and an expression is given for the growth or decay rate of the waves for convective instability. Detailed numerical calculations have been made for the growth or decay rate of the wave for different values of the anisotropy ratio T/TII of the perpendicular and parallel temperatures, and the Mcllwain parameter L. It is found that for parallel propagation, the waves are unstable for frequencies less than the cyclotron frequency and the instability depends only on the anisotropy parameter T/TII and not on the loss cone index i