Impact of Target-level, High-mode Perturbations on 2-D DRACO Simulations of Direct-Drive Implosions at OMEGA

We present ensemble comparisons between measured and predicted yield and areal density (ρR) using a database of high-resolution, post-shot simulations that incorporate laser imprint and additional high-mode perturbations, suspected to arise from target imperfections. Previous 2-D DRACO (Ref. [1]) simulations, which assumed smooth targets, indicated a weak influence of laser imprint on implosions with moderate stability (inflight adiabat > 4, inflight aspect ratio < 35). However, comparisons with experimental data revealed the need for an additional, significant degradation source to reconcile discrepancies. By including additional high-mode perturbations (up to mode 120), we achieved significant improvements in the prediction of neutron yield measurements across a wide range of implosions. We hypothesize that these high-mode perturbations may effectively mimic the impact of target imperfections. These findings align with hypotheses that target defects contribute to early core emission signatures not captured in previous simulations (Ref. [2]). This motivates further investigation into accurately modeling the impact of target imperfections.