Increasing Performance of Direct-Drive Inertial Confinement Fusion Implosions via Enhanced Energy Coupling

Recent advances in predictive statistical modeling have led to record fusion yields and increased overall performance, as measured by the normalized no-alpha Lawson parameter cno a extrapolated to 2 MJ of symmetric drive. These increases were driven largely by (a) the introduction of silicon dopant into the ablator, which increases both collisional absorption and cross-beam energy transfer mitigation, and (b) reducing the pulse duration to couple energy more effectively at early times, when the target is relatively unconverged and silicon dopant is present throughout the corona. We will also present the results of dedicated experiments on OMEGA designed to test LILAC’s coupling model late in the pulse, which has shown good agreement with LILAC yields and areal densities. Finally, hydrodynamic scaling of the best-performing implosions to 2 MJ of symmetric drive gives cno a > 0.8, yield amplification > 3, and scaled fusion yield over 700 kJ.