Investigation of stimulated Raman scattering in longitudinal magnetized plasma by theory and kinetic simulation

Abstract

Stimulated Raman scattering (SRS) in a longitudinal magnetized plasma is studied by theoretical analysis and kinetic simulation. The linear growth rate derived via one-dimensional fluid theory shows the dependence on the plasma density, electron temperature, and magnetic field intensity. One-dimensional particle-in-cell simulations are carried out to examine the kinetic evolution of SRS under low magnetic intensity of There are two density regions distinguished in which the absolute growth of enveloped electrostatic waves and spectrum present quite different characteristics. In a relatively low-density plasma (), the plasma wave presents typical absolute growth and the magnetic field alleviates linear SRS. While in the plasma whose density is near the cut-off point (), the magnetic field induces a spectral splitting of the backscattering and forward-scattering waves. It has been observed in simulations and verified by theoretical analysis. Due to this effect, the onset of reflectivity delays, and the plasma waves form high-frequency oscillation and periodic envelope structure. The split wavenumber is proportional to the magnetic field intensity and plasma density. These studies provide novel insight into the kinetic behavior of SRS in magnetized plasmas.