Ion heating enhancement in fast ignition through mid-Z doping

In inertial confinement fusion, the central ignition scheme operates on a nanosecond ignition timescale, establishing thermal equilibrium between electron and ion temperatures. In contrast, the fast ignition (FI) approach reduces this timescale to approximately 10 picoseconds, resulting in an electron-ion temperature non-equilibrium. In FI, doping the DT target with a specific amount of mid-to-high Z elements could effectively shorten the electron-ion equilibrium time, enhance the ion temperature, and consequently increase the neutron yield. In this work, we study the effects of the dopant atomic number and concentration on fusion neutron yield under different ignition laser parameters and target densities. Our theoretical analysis and simulations indicate that optimizing the doping concentration can significantly elevate neutron yield. Specifically, doping a 100 g cm−3 DT target with 0.16% Mo can increase the neutron yield obtained from a 40 kJ, 5 ps laser pulse by a factor of three and trigger the α-particle self-heating.