Probing ion species separation and ion thermal decoupling in shock-driven implosions using multiple nuclear reaction histories.

Simultaneously measured DD, DT, and D³He reaction histories are used to probe the impacts of multi-ion physics during the shock phase of inertial confinement fusion implosions. In these relatively hydrodynamiclike (burn-averaged Knudsen number ⟨ N K ⟩ ∼0.3) shock-driven implosions, average-ion hydrodynamic DUED simulations are able to reasonably match burnwidths, nuclear yields, and ion temperatures. However, kinetic-ion FPION simulations are able to better simulate the timing differences and time-resolved reaction rate ratios between DD, DT, and D³He reactions. FPION simulations suggest that the D³He/DT reaction rate ratio is most directly impacted by ion species separation between the ³He and T ions, whereas the D³He/DD reaction rate ratio is affected by both ion species separation and ion temperature decoupling effects. [ABSTRACT FROM AUTHOR]