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Title: Hohlraum modeling for opacity experiments on the National Ignition Facility

This paper discusses the modeling of experiments that measure iron opacity in local thermodynamic equilibrium (LTE) using laser-driven hohlraums at the National Ignition Facility (NIF). A previous set of experiments fielded at Sandia's Z facility [Bailey et al., Nature 517, 56 (2015)] have shown up to factors of two discrepancies between the theory and experiment, casting doubt on the validity of the opacity models. The purpose of the new experiments is to make corroborating measurements at the same densities and temperatures, with the initial measurements made at a temperature of 160 eV and an electron density of 0.7 × 10 22 cm -3. The X-ray hot spots of a laser-driven hohlraum are not in LTE, and the iron must be shielded from a direct line-of-sight to obtain the data [Perry et al., Phys. Rev. B 54, 5617 (1996)]. This shielding is provided either with the internal structure (e.g., baffles) or external wall shapes that divide the hohlraum into a laser-heated portion and an LTE portion. In contrast, most inertial confinement fusion hohlraums are simple cylinders lacking complex gold walls, and the design codes are not typically applied to targets like those for the opacity experiments. We will discuss the initialmore » basis for the modeling using LASNEX, and the subsequent modeling of five different hohlraum geometries that have been fielded on the NIF to date. This includes a comparison of calculated and measured radiation temperatures.« less
Authors:
ORCiD logo [1] ;  [1] ;  [2] ; ORCiD logo [1] ;  [1] ; ORCiD logo [1] ;  [2] ;  [3] ;  [1] ; ORCiD logo [1] ; ORCiD logo [1] ;  [2] ;  [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. National Security Technologies, LLC, Livermore, CA (United States)
Publication Date:
Report Number(s):
LA-UR-17-28949
Journal ID: ISSN 1070-664X
Grant/Contract Number:
AC52-06NA25396; AC52-07NA27344; AC52-06NA25946
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 6; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Opacity-on-NIF; hohlraum modeling
OSTI Identifier:
1479930
Alternate Identifier(s):
OSTI ID: 1441085

Dodd, Evan S., DeVolder, Barbara Gloria, Martin, M. E., Krasheninnikova, Natalia Sergeevna, Tregillis, Ian Lee, Perry, Theodore Sonne, Heeter, R. F., Opachich, Y. P., Moore, A. S., Kline, John L., Johns, Heather Marie, Liedahl, D. A., Cardenas, Tana, Olson, Richard Edward, Wilde, Bernhard Heinz, and Urbatsch, Todd James. Hohlraum modeling for opacity experiments on the National Ignition Facility. United States: N. p., Web. doi:10.1063/1.5026285.
Dodd, Evan S., DeVolder, Barbara Gloria, Martin, M. E., Krasheninnikova, Natalia Sergeevna, Tregillis, Ian Lee, Perry, Theodore Sonne, Heeter, R. F., Opachich, Y. P., Moore, A. S., Kline, John L., Johns, Heather Marie, Liedahl, D. A., Cardenas, Tana, Olson, Richard Edward, Wilde, Bernhard Heinz, & Urbatsch, Todd James. Hohlraum modeling for opacity experiments on the National Ignition Facility. United States. doi:10.1063/1.5026285.
Dodd, Evan S., DeVolder, Barbara Gloria, Martin, M. E., Krasheninnikova, Natalia Sergeevna, Tregillis, Ian Lee, Perry, Theodore Sonne, Heeter, R. F., Opachich, Y. P., Moore, A. S., Kline, John L., Johns, Heather Marie, Liedahl, D. A., Cardenas, Tana, Olson, Richard Edward, Wilde, Bernhard Heinz, and Urbatsch, Todd James. 2018. "Hohlraum modeling for opacity experiments on the National Ignition Facility". United States. doi:10.1063/1.5026285. https://www.osti.gov/servlets/purl/1479930.
@article{osti_1479930,
title = {Hohlraum modeling for opacity experiments on the National Ignition Facility},
author = {Dodd, Evan S. and DeVolder, Barbara Gloria and Martin, M. E. and Krasheninnikova, Natalia Sergeevna and Tregillis, Ian Lee and Perry, Theodore Sonne and Heeter, R. F. and Opachich, Y. P. and Moore, A. S. and Kline, John L. and Johns, Heather Marie and Liedahl, D. A. and Cardenas, Tana and Olson, Richard Edward and Wilde, Bernhard Heinz and Urbatsch, Todd James},
abstractNote = {This paper discusses the modeling of experiments that measure iron opacity in local thermodynamic equilibrium (LTE) using laser-driven hohlraums at the National Ignition Facility (NIF). A previous set of experiments fielded at Sandia's Z facility [Bailey et al., Nature 517, 56 (2015)] have shown up to factors of two discrepancies between the theory and experiment, casting doubt on the validity of the opacity models. The purpose of the new experiments is to make corroborating measurements at the same densities and temperatures, with the initial measurements made at a temperature of 160 eV and an electron density of 0.7 × 1022 cm-3. The X-ray hot spots of a laser-driven hohlraum are not in LTE, and the iron must be shielded from a direct line-of-sight to obtain the data [Perry et al., Phys. Rev. B 54, 5617 (1996)]. This shielding is provided either with the internal structure (e.g., baffles) or external wall shapes that divide the hohlraum into a laser-heated portion and an LTE portion. In contrast, most inertial confinement fusion hohlraums are simple cylinders lacking complex gold walls, and the design codes are not typically applied to targets like those for the opacity experiments. We will discuss the initial basis for the modeling using LASNEX, and the subsequent modeling of five different hohlraum geometries that have been fielded on the NIF to date. This includes a comparison of calculated and measured radiation temperatures.},
doi = {10.1063/1.5026285},
journal = {Physics of Plasmas},
number = 6,
volume = 25,
place = {United States},
year = {2018},
month = {6}
}