The Impact of Target-Layer Imperfections on Performance Sensitivity to Laser Imprint for Direct-Drive Inertial Confinement Fusion (DDICF) Implosions on OMEGA.
ORAL
Abstract
Recent experimental results showed that the highest performing class of DDICF implosions on OMEGA at adiabat ~4.5 are not dominated by degradation from laser imprint1, but are significant at adiabat~3.5 . This was shown by measuring changes in neutron yield and neutron-averaged areal density (ρR) to varying levels of laser spot smoothing by spectral dispersion (SSD) and observing performance saturation for sufficiently high SSD bandwidth. We report on a 2-D simulation study with DRACO2 seeking to reproduce these trends by introducing target imperfections via a surface-roughness spectrum, in addition to laser imprint. While previous DRACO simulation results with laser imprinting alone did not show performance saturation at the SSD levels observed, a mechanism to reproduce it could be done through an additional, high-mode perturbation source that is independent of SSD. The perturbation added is characterized by <1 um amplitude, high-mode imperfections (l=60 to 120 spectrum suggested by 2D VISAR measurements3) at the fuel-ablator interface, in addition to a NIF standard surface roughness spectrum. The results from this study are valuable for determining what perturbation seeds need to be included in simulations in order to create scientifically credible performance extrapolations for future target designs.
*This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856.
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Publication:J. P. Knauer, R. Betti, D. Patel, V. Gopalaswamy, D. Cao, A. Lees, A. Shvydky, M. J. Bonino, E. M. Campbell, T. J. B. Collins, C. J. Forrest, V. Yu. Glebov, V. N, Goncharov, D. R. Harding, J. A. Marozas, F. J. Marshall, P. W. McKenty, J. L. Peebles, P. B. Radha, S. P. Regan, T. C. Sangster, C. Stoeckl, M. Gatu Johnson, J. A. Frenje, R. D. Petrasso, L. Aghaian, J. Murray, B. Serrato, D. Guzman, M. Hoppe, C. Shuldberg, and M. Farrell, presented at the 64th American Physical Society Division of Plasma Physics, Spokane, WA, 17–21 October 2022 (invited).
P. B. Radha, V. N. Goncharov, T. J. B. Collins, J. A. Delettrez, Y. Elbaz, V. Yu. Glebov,R. L. Keck, D. E. Keller, J. P. Knauer, J. A. Marozas, F. J. Marshall, P. W. McKenty, D.D. Meyerhofer, S. P. Regan, T. C. Sangster, D. Shvarts, S. Skupsky, Y. Srebro, R. P. J.Town, and C. Stoeckl, Phys. Plasmas12, 032702 (2005).
J. L. Peebles, S. X. Hu, W. Theobald, V. N. Goncharov, N. Whiting, E. M. Campbell, T. R. Boehly, S. P. Regan, P. M. Celliers, S. J. Ali, and G. Duchateau, presented at the 61st Meeting of the American Physical Society Division of Plasma Physics, Fort Lauderdale, FL, 21–25 October 2019.
Presenters
Duc M Cao
University of Rochester, Laboratory for Laser Energetics
U. Rochester/LLE
Authors
Duc M Cao
University of Rochester, Laboratory for Laser Energetics
U. Rochester/LLE
James P Knauer
University of Rochester
Riccardo Betti
Laboratory for Laser Energy, Rochester, NY, USA.
University of Rochester
LLE, Univ of Rochester
Dhrumir P Patel
University of Rochester
Varchas Gopalaswamy
Laboratory for Laser Energetics - Rochester
Aarne Lees
University of Rochester
Alexander Shvydky
Lab for Laser Energetics
Laboratory for Laser Energetics
Laboratory for Laser Energetics, University of Rochester
Cliff A Thomas
University of Rochester
John A Marozas
Laboratory for Laser Energetics, University of Rochester
Patrick m McKenty
Laboratory for Laser Energetics, University of Rochester
P. B Radha
Laboratory for Laser Energetics - Rochester
University of Rochester
Laboratory for Laser Energetics
TImothy J Collins
University of Rochester
Valeri N Goncharov
University of Rochester, Laboratory for Laser Energetics
Chad J Forrest
LLE
Lab for Laser Energetics
University of Rochester
University of Rochester, Laboratory for Laser Energetics
Laboratory for Laser Energetics
Christian Stoeckl
University of Rochester
Vladimir Glebov
Lab for Laser Energetics
University of Rochester
Mark J Bonino
Laboratory for Laser Energetics
University of Rochester, Laboratory for Laser Energetics
University of Rochester
David R Harding
Laboratory for Laser Energetics
Laboratory for Laser Energetics, University of Rochester
University of Rochester, Laboratory for Laser Energetics
University of Rochester
Frederic J Marshall
University of Rochester
Jonathan L Peebles
Laboratory for Laser Energetics
Sean P Regan
Laboratory for Laser Energetics, University of Rochester
