Convective gain of stimulated Brillouin scattering in long-scale length, two-ion-component plasmas

The linear kinetic theory is developed for the convective amplification of stimulated Brillouin scattering in a plasma containing two distinct ion species. A computationally tractable expression for the gain coefficient Q is obtained by, first, restricting consideration to growth from the two possible weakly damped ion modes in the two-ion-species plasma and, second, invoking the two-mode approximation for ε−1, the ion response function, in the plasma. Furthermore, a practical procedure is presented for efficiently obtaining Q over the mesh of a large-scale hydrodynamic simulation of a laser-irradiated target. The theory and its application are demonstrated in the simulation of a simple gas target.