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Title: Return current instability driven by a temperature gradient in ICF plasmas

Abstract

Here, hot plasmas with strong temperature gradients in inertial confinement fusion (ICF) experiments are examined for ion acoustic instabilities produced by electron heat flow. The return current instability (RCI) due to a neutralizing current of cold electrons arising in response to a large electron heat flux has been considered. First, the linear threshold and growth rates are derived in the nonlocal regime of thermal transport. They are compared with the results of Vlasov-Fokker-Planck (VFP) simulations in one spatial dimension. Very good agreement has been found between kinetic VFP simulations and the linear theory of the RCI. A quasi-stationary state of ion acoustic turbulence produced by the RCI is achieved in the VFP simulations. Saturation of the RCI involves heating of ions in the tail of the ion distribution function and convection of the enhanced ion acoustic fluctuations from the unstable region of the plasma. Further evolution of the ion acoustic turbulence and its effects on absorption and transport are also discussed.

Authors:
 [1];  [2];  [3];  [2]
  1. Univ. of Alberta, Edmonton, AB (Canada)
  2. Russian Academy of Science, Moscow (Russia)
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United Kingdom)
Sponsoring Org.:
USDOE
OSTI Identifier:
1393332
Report Number(s):
LLNL-PROC-737115
Journal ID: ISSN 0741-3335
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Plasma Physics and Controlled Fusion
Additional Journal Information:
Journal Volume: 60; Journal Issue: 1; Conference: Presented at: European Physical Society Plasma Physics, Belfast (United Kingdom), 26-30 Jun 2017; Journal ID: ISSN 0741-3335
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; return current instability; ion acoustic turbulence; anomalous absorption and transport

Citation Formats

Rozmus, W., Brantov, A. V., Sherlock, M., and Bychenkov, V. Yu. Return current instability driven by a temperature gradient in ICF plasmas. United States: N. p., 2017. Web. doi:10.1088/1361-6587/aa868d.
Rozmus, W., Brantov, A. V., Sherlock, M., & Bychenkov, V. Yu. Return current instability driven by a temperature gradient in ICF plasmas. United States. doi:10.1088/1361-6587/aa868d.
Rozmus, W., Brantov, A. V., Sherlock, M., and Bychenkov, V. Yu. Thu . "Return current instability driven by a temperature gradient in ICF plasmas". United States. doi:10.1088/1361-6587/aa868d.
@article{osti_1393332,
title = {Return current instability driven by a temperature gradient in ICF plasmas},
author = {Rozmus, W. and Brantov, A. V. and Sherlock, M. and Bychenkov, V. Yu},
abstractNote = {Here, hot plasmas with strong temperature gradients in inertial confinement fusion (ICF) experiments are examined for ion acoustic instabilities produced by electron heat flow. The return current instability (RCI) due to a neutralizing current of cold electrons arising in response to a large electron heat flux has been considered. First, the linear threshold and growth rates are derived in the nonlocal regime of thermal transport. They are compared with the results of Vlasov-Fokker-Planck (VFP) simulations in one spatial dimension. Very good agreement has been found between kinetic VFP simulations and the linear theory of the RCI. A quasi-stationary state of ion acoustic turbulence produced by the RCI is achieved in the VFP simulations. Saturation of the RCI involves heating of ions in the tail of the ion distribution function and convection of the enhanced ion acoustic fluctuations from the unstable region of the plasma. Further evolution of the ion acoustic turbulence and its effects on absorption and transport are also discussed.},
doi = {10.1088/1361-6587/aa868d},
journal = {Plasma Physics and Controlled Fusion},
number = 1,
volume = 60,
place = {United States},
year = {Thu Oct 12 00:00:00 EDT 2017},
month = {Thu Oct 12 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
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