Beam driven temporal growth and spatial amplification of electrostatic waves in a partially spin polarized degenerate magnetized plasma

Abstract

The temporal growth and spatial amplification of electrostatic waves due to the interaction of an electron beam with a partially spin polarized degenerate magnetized plasma are studied. Using Fourier analysis, a generalized linear dispersion relation is derived for parallel propagating electrostatic waves in the presence of electron spin polarization. The electron spin polarization gives birth to a new spin-dependent wave (spin electron acoustic wave) in the real wave spectrum. Furthermore, increasing spin polarization reduces the temporal growth rate of the unstable mode. Regarding spatial amplification (magnitude of the imaginary wave number), it is found that spin polarization significantly affects the magnitude of both the real and the imaginary wave numbers. Additionally, how the various other parameters such as electron beam density, beam thermal speed, and streaming speed of the beam electron influence the temporal growth and spatial rates is also discussed. These effects would have a strong bearing on instability phenomena in the degenerate metallic and semiconductor plasmas and in astrophysical plasmas.