Recent experimental demonstrations of ignition and target gain in inertial confinement fusion (ICF) have stimulated interest in exploring the fundamental physics of violent deuterium-tritium (DT) burn in high-gain ICF targets. A significant DT-burn fraction is a necessary condition for high energy gain and large neutron yields ($>100\mathrm{MJ}$). Using classical molecular-dynamics (MD) simulations and a hybrid fluid-kinetic model, we examine how a large fraction of low-energy $\alpha$ particles can kick D and T ions out of equilibrium in high-gain ICF targets. The MD results suggest that (1) temperatures of $T_D$ and $T_T$ can differ by as much as $\sim 20\%$ of their mean temperature and (2) the deviation of the DT energy distribution from the Maxwell-Boltzmann function can exceed $\sim 30\%$. Some of these MD observations, such as the preferential heating of D ions by low-energy $\alpha$ particles and the temperature separation, can be explained by a proposed hybrid fluid-kinetic model. The implication of such nonequilibrium effects on the DT reactivity is also discussed.

Close

PrevNext

View figure in article

• Inertial confinement fusion
• Plasma thermodynamics
• Plasma-particle interactions
• Hot dense plasma
• Inertially confined plasmas
• Fokker-Planck & Vlasov model
• Molecular dynamics
• Plasma kinetic theory
• Two-fluid & multi-fluid model