skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A comparison of non-local electron transport models for laser-plasmas relevant to inertial confinement fusion

Authors:
 [1]; ORCiD logo [2];  [2]
  1. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA
  2. York Plasma Institute, University of York, York YO10 5DD, United Kingdom
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1374228
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 8; Related Information: CHORUS Timestamp: 2018-02-14 14:36:25; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Sherlock, M., Brodrick, J. P., and Ridgers, C. P.. A comparison of non-local electron transport models for laser-plasmas relevant to inertial confinement fusion. United States: N. p., 2017. Web. doi:10.1063/1.4986095.
Sherlock, M., Brodrick, J. P., & Ridgers, C. P.. A comparison of non-local electron transport models for laser-plasmas relevant to inertial confinement fusion. United States. doi:10.1063/1.4986095.
Sherlock, M., Brodrick, J. P., and Ridgers, C. P.. 2017. "A comparison of non-local electron transport models for laser-plasmas relevant to inertial confinement fusion". United States. doi:10.1063/1.4986095.
@article{osti_1374228,
title = {A comparison of non-local electron transport models for laser-plasmas relevant to inertial confinement fusion},
author = {Sherlock, M. and Brodrick, J. P. and Ridgers, C. P.},
abstractNote = {},
doi = {10.1063/1.4986095},
journal = {Physics of Plasmas},
number = 8,
volume = 24,
place = {United States},
year = 2017,
month = 8
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on August 8, 2018
Publisher's Accepted Manuscript

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • In some regions of a laser driven inertial fusion target, the electron mean-free path can become comparable to or even longer than the electron temperature gradient scale-length. This can be particularly important in shock-ignited (SI) targets, where the laser-spike heated corona reaches temperatures of several keV. In this case, thermal conduction cannot be described by a simple local conductivity model and a Fick's law. Fluid codes usually employ flux-limited conduction models, which preserve causality, but lose important features of the thermal flow. A more accurate thermal flow modeling requires convolution-like non-local operators. In order to improve the simulation of SImore » targets, the non-local electron transport operator proposed by Schurtz-Nicola├»-Busquet [G. P. Schurtz et al., Phys. Plasmas 7, 4238 (2000)] has been implemented in the DUED fluid code. Both one-dimensional (1D) and two-dimensional (2D) simulations of SI targets have been performed. 1D simulations of the ablation phase highlight that while the shock profile and timing might be mocked up with a flux-limiter; the electron temperature profiles exhibit a relatively different behavior with no major effects on the final gain. The spike, instead, can only roughly be reproduced with a fixed flux-limiter value. 1D target gain is however unaffected, provided some minor tuning of laser pulses. 2D simulations show that the use of a non-local thermal conduction model does not affect the robustness to mispositioning of targets driven by quasi-uniform laser irradiation. 2D simulations performed with only two final polar intense spikes yield encouraging results and support further studies.« less
  • Measurements of the hot-electron generation by the two-plasmon-decay instability are made in plasmas relevant to direct-drive inertial confinement fusion. Density-scale lengths of 400 {micro}m at n{sub cr}/4 in planar CH targets allowed the two-plasmon-decay instability to be driven to saturation for vacuum intensities above ~3.5 x 10{sup 14} W cm{sup -2}. In the saturated regime, ~1% of the laser energy is converted to hot electrons. The hot-electron temperature is measured to increase rapidly from 25 to 90 keV as the laser beam intensity is increased from 2 to 7 x 10{sup 14} W cm{sup -2}. This increase in the hot-electronmore » temperature is compared with predictions from nonlinear Zakharov models.« less
  • A novel x-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any x-ray photon energy range, over a large domain, on a single-shot basis. The device (named energy-encoded pinhole camera) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available x-ray spectral domain is only limited by the quantum efficiency of scientific-grade x-ray CCD cameras, thus extending from a few keV up to a few tens of keV. Spectral 2D images of the emitting plasmamore » can be obtained at any x-ray photon energy provided that a sufficient number of photons had been collected at the desired energy. Results from recent inertial confinement fusion related experiments will be reported in order to detail the new diagnostic.« less
  • Cited by 1