Particle-in-cell simulations of parametric decay instabilities at the upper hybrid layer of fusion plasmas to determine their primary threshold

Mads Givskov Senstius*, Stefan Kragh Nielsen, R. G. Vann, Søren Kjer Hansen

*Corresponding author for this work

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Abstract

Parametric decay instabilities (PDIs) are nonlinear processes by which energy from a strong pump wave may be directed into other waves at other frequencies, in particular natural modes of the medium, provided that energy and momentum are conserved. The particle-in-cell (PIC) code EPOCH is used to simulate PDIs in a magnetically confined fusion plasma converting a 105 GHz microwave X-mode pump wave into electrostatic daughter waves at the upper hybrid (UH) layer. Modes associated with the PDIs as well as a linearly converted electron Bernstein wave (EBW) are identified in f- and k-space. The PDI daughter modes are found to agree with experimental observations from ASDEX Upgrade as well as with analytical predictions, showing a nonlinear increase in power above a predicted threshold.
Original languageEnglish
Article number025010
JournalPlasma Physics and Controlled Fusion
Volume62
Issue number2
Number of pages13
ISSN0741-3335
DOIs
Publication statusPublished - 2020

Keywords

  • Parametric decay instabilities
  • Particle in cell
  • Upper hybrid layer
  • Electron Bernstein waves

Cite this

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title = "Particle-in-cell simulations of parametric decay instabilities at the upper hybrid layer of fusion plasmas to determine their primary threshold",
abstract = "Parametric decay instabilities (PDIs) are nonlinear processes by which energy from a strong pump wave may be directed into other waves at other frequencies, in particular natural modes of the medium, provided that energy and momentum are conserved. The particle-in-cell (PIC) code EPOCH is used to simulate PDIs in a magnetically confined fusion plasma converting a 105 GHz microwave X-mode pump wave into electrostatic daughter waves at the upper hybrid (UH) layer. Modes associated with the PDIs as well as a linearly converted electron Bernstein wave (EBW) are identified in f- and k-space. The PDI daughter modes are found to agree with experimental observations from ASDEX Upgrade as well as with analytical predictions, showing a nonlinear increase in power above a predicted threshold.",
keywords = "Parametric decay instabilities, Particle in cell, Upper hybrid layer, Electron Bernstein waves",
author = "Senstius, {Mads Givskov} and Nielsen, {Stefan Kragh} and Vann, {R. G.} and Hansen, {S{\o}ren Kjer}",
year = "2020",
doi = "10.1088/1361-6587/ab49ca",
language = "English",
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journal = "Plasma Physics and Controlled Fusion",
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publisher = "IOP Publishing",
number = "2",

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TY - JOUR

T1 - Particle-in-cell simulations of parametric decay instabilities at the upper hybrid layer of fusion plasmas to determine their primary threshold

AU - Senstius, Mads Givskov

AU - Nielsen, Stefan Kragh

AU - Vann, R. G.

AU - Hansen, Søren Kjer

PY - 2020

Y1 - 2020

N2 - Parametric decay instabilities (PDIs) are nonlinear processes by which energy from a strong pump wave may be directed into other waves at other frequencies, in particular natural modes of the medium, provided that energy and momentum are conserved. The particle-in-cell (PIC) code EPOCH is used to simulate PDIs in a magnetically confined fusion plasma converting a 105 GHz microwave X-mode pump wave into electrostatic daughter waves at the upper hybrid (UH) layer. Modes associated with the PDIs as well as a linearly converted electron Bernstein wave (EBW) are identified in f- and k-space. The PDI daughter modes are found to agree with experimental observations from ASDEX Upgrade as well as with analytical predictions, showing a nonlinear increase in power above a predicted threshold.

AB - Parametric decay instabilities (PDIs) are nonlinear processes by which energy from a strong pump wave may be directed into other waves at other frequencies, in particular natural modes of the medium, provided that energy and momentum are conserved. The particle-in-cell (PIC) code EPOCH is used to simulate PDIs in a magnetically confined fusion plasma converting a 105 GHz microwave X-mode pump wave into electrostatic daughter waves at the upper hybrid (UH) layer. Modes associated with the PDIs as well as a linearly converted electron Bernstein wave (EBW) are identified in f- and k-space. The PDI daughter modes are found to agree with experimental observations from ASDEX Upgrade as well as with analytical predictions, showing a nonlinear increase in power above a predicted threshold.

KW - Parametric decay instabilities

KW - Particle in cell

KW - Upper hybrid layer

KW - Electron Bernstein waves

U2 - 10.1088/1361-6587/ab49ca

DO - 10.1088/1361-6587/ab49ca

M3 - Journal article

VL - 62

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 2

M1 - 025010

ER -