LSP modeling of ultra-intense lasers on cone-coupled wire targets: effect of cone thickness

Experiments with ultra-intense laser pulses incident on cone-coupled wire targets can potentially yield valuable information on the physics relevant to the fast ignition fusion regime. Using the Particle-In-Cell code LSP, we present simulations with fully consistent laser E \& B fields and over 60 million fully kinetic particles designed to model mm-scale cone-wire experiments conducted with the Titan laser at LLNL. Focusing on Cu K$_\alpha$ x-ray line emission -- an informative diagnostic of the population of hot electrons -- we investigate and explain the strong experimental trend that the irradiation of thicker cones produces fewer Cu K$_\alpha$ photons. Comparison to other studies and implications for the feasibility of the fast ignition fusion concept are discussed.