Observations of multiple nuclear reaction histories and fuel-ion species dynamics in shock-driven inertial confinement fusion implosions
Fuel-ion species dynamics in hydrodynamiclike shock-driven DT3He-filled inertial confinement fusion
implosion is quantitatively assessed for the first time using simultaneously measured D3He and DT reaction
histories. These reaction histories are measured with the particle x-ray temporal diagnostic, which captures
the relative timing between different nuclear burns with unprecedented precision (∼10 ps). The observed
50 +- 10 ps earlier D3He reaction history timing (relative to DT) cannot be explained by average-ion
hydrodynamic simulations and is attributed to fuel-ion species separation between the D, T, and 3He ions
during shock convergence and rebound. At the onset of the shock burn, inferred 3He/T fuel ratio in the burn
region using the measured reaction histories is much higher as compared to the initial gas-filled ratio. As T
and 3He have the same mass but different charge, these results indicate that the charge-to-mass ratio plays
an important role in driving fuel-ion species separation during strong shock propagation even for these
hydrodynamiclike plasmas.