Fuel-ion diffusion in shock-driven inertial confinement fusion implosions

Abstract

The impact of fuel-ion diffusion in inertial confinement fusion implosions is assessed using nuclear reaction yield ratios and reaction histories. In T3He-gas-filled (with trace D) shock-driven implosions, the observed TT/T3He yield ratio is ∼2× lower than expected from temperature scaling. In D3He-gas-filled (with trace T) shock-driven implosions, the timing of the D3He reaction history is ∼50 ps earlier than those of the DT reaction histories, and average-ion hydrodynamic simulations cannot reconcile this timing difference. Both experimental observations are consistent with reduced T ions in the burn region as predicted by multi-ion diffusion theory and particle-in-cell simulations.The impact of fuel-ion diffusion in inertial confinement fusion implosions is assessed using nuclear reaction yield ratios and reaction histories. In T3He-gas-filled (with trace D) shock-driven implosions, the observed TT/T3He yield ratio is ∼2× lower than expected from temperature scaling. In D3He-gas-filled (with trace T) shock-driven implosions, the timing of the D3He reaction history is ∼50 ps earlier than those of the DT reaction histories, and average-ion hydrodynamic simulations cannot reconcile this timing difference. Both experimental observations are consistent with reduced T ions in the burn region as predicted by multi-ion diffusion theory and particle-in-cell simulations.