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Forrest, Chad

Publications and source records attributed to Forrest, Chad.

Report-out of Breakout Group 6: Time-resolved Neutron Energy Spectra [Slides]

Summary: More than 40 scientists met to discuss time-resolved neutron energy spectra; Six talks were given covering physics motivation and five candidate techniques; Presentations stimulated much discussion and questions & answers, and led to required next steps for each technique to enable downselection.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Observation of persistent species temperature separation in inertial confinement fusion mixtures

The injection and mixing of contaminant mass into the fuel in inertial confinement fusion (ICF) implosions is a primary factor preventing ignition. ICF experiments have recently achieved an alpha-heating regime, in which fusion self-heating is the dominant source of yield, by reducing the susceptibility of implosions to instabilities that inject this mass. We report the results of unique separated reactants implosion experiments studying pre-mixed contaminant as well as detailed high-resolution three-dimensional simulations that are in good agreement with experiments. At conditions relevant to mixing regions in high-yield implosions, we observe persistent chunks of contaminant that do not achieve thermal equilibrium with the fuel throughout the burn phase. The assumption of thermal equilibrium is made in nearly all computational ICF modeling and methods used to infer levels of contaminant from experiments. We estimate that these methods may underestimate the amount of contaminant by a factor of two or more.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗