Vlasov theory of magnetized cross-beam energy transfer in a high-energy-density plasma

Cross-beam energy transfer (CBET) is a nonlinear laser–plasma interaction instability where power is transferred between two intersecting lasers in a plasma environment. CBET plays an important role in controlling the implosion shape and laser drive in both indirect and direct drive ignition designs. This article uses an approximate form of the ponderomotive force to derive analytical expressions for the CBET energy spatial transfer rate between lasers in a magnetized plasma using Vlasov–Maxwell theory with a background uniform magnetic field. Magnetization adds significantly greater complexity but introduces a richness to the CBET physics. Several findings include the activation of transfer between cross-polarized lasers, the reduction of transfer between parallel-polarized lasers, and significant power transfer at magnetized plasma modes, including ion Bernstein, lower hybrid, and fast Alfvén modes. We discuss potential impacts of these results on inertial confinement fusion ignition designs relevant to cases with self-generated or externally applied magnetic fields.