Geometric scalings for the electrostatically driven helical plasma state

Akçay, Cihan; Finn, John M.; Nebel, Richard A.; Barnes, Daniel C.

doi:10.1063/1.5011774

Title: Geometric scalings for the electrostatically driven helical plasma state

Abstract

A new plasma state has been investigated [Akcay et al., Phys. Plasmas 24, 052503 (2017)], with a uniform applied axial magnetic field in a periodic cylinder of length $L=2πR$, driven by helical electrodes. The drive is single helicity, depending on $mθ+kz=mθ-nζ$, where $ζ=z/R$ and $k=-n/R$. For strong $(m,n)=(1,1)$ drive, the state was found to have a strong axial mean current density, with a mean-field safety factor $$q_0(r)$$ just above the pitch of the electrodes $m/n=1$ in the interior. This state has possible applications to DC electrical transformers and tailoring of the current profile in tokamaks. Here, we study two geometric issues of interest for these applications: (i) scaling of properties with the plasma length or aspect ratio and (ii) behavior for different helicities, specifically $(m,n)=(1,n)$ for n > and $(m,n)=(2,1)$.

Authors:

Akçay, Cihan ^[1]; Finn, John M. ^[1]; Nebel, Richard A. ^[1]; Barnes, Daniel C. ^[1]

Tibbar Plasma Technologies, Los Alamos, NM (United States)

Publication Date:: Wed Dec 27 00:00:00 EST 2017

Research Org.:: Tibbar Plasma Technologies, Los Alamos, NM (United States)

Sponsoring Org.:: USDOE Advanced Research Projects Agency - Energy (ARPA-E)

OSTI Identifier:: 1524594

Alternate Identifier(s):: OSTI ID: 1414984

Grant/Contract Number:: AR0000677

Resource Type:: Accepted Manuscript

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 24; Journal Issue: 12; Journal ID: ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats


                    Akçay, Cihan, Finn, John M., Nebel, Richard A., and Barnes, Daniel C. Geometric scalings for the electrostatically driven helical plasma state.  United States: N. p., 2017. 
Web.  doi:10.1063/1.5011774.

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                    Akçay, Cihan, Finn, John M., Nebel, Richard A., & Barnes, Daniel C. Geometric scalings for the electrostatically driven helical plasma state.  United States.  https://doi.org/10.1063/1.5011774

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                    Akçay, Cihan, Finn, John M., Nebel, Richard A., and Barnes, Daniel C. Wed .  
"Geometric scalings for the electrostatically driven helical plasma state".  United States.  https://doi.org/10.1063/1.5011774.  https://www.osti.gov/servlets/purl/1524594.

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@article{osti_1524594,

  title        = {Geometric scalings for the electrostatically driven helical plasma state},

  author       = {Akçay, Cihan and Finn, John M. and Nebel, Richard A. and Barnes, Daniel C.},

  abstractNote = {A new plasma state has been investigated [Akcay et al., Phys. Plasmas 24, 052503 (2017)], with a uniform applied axial magnetic field in a periodic cylinder of length $L=2πR$, driven by helical electrodes. The drive is single helicity, depending on $mθ+kz=mθ-nζ$, where $ζ=z/R$ and $k=-n/R$. For strong $(m,n)=(1,1)$ drive, the state was found to have a strong axial mean current density, with a mean-field safety factor $q_0(r)$ just above the pitch of the electrodes $m/n=1$ in the interior. This state has possible applications to DC electrical transformers and tailoring of the current profile in tokamaks. Here, we study two geometric issues of interest for these applications: (i) scaling of properties with the plasma length or aspect ratio and (ii) behavior for different helicities, specifically $(m,n)=(1,n)$ for n > and $(m,n)=(2,1)$.},

  doi          = {10.1063/1.5011774},

  journal      = {Physics of Plasmas},

  number       = 12,

  volume       = 24,

  place        = {United States},

  year         = {Wed Dec 27 00:00:00 EST 2017},

  month        = {Wed Dec 27 00:00:00 EST 2017}

}

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https://doi.org/10.1063/1.5011774

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Cited by: 1 work

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Figures / Tables:

FIG. 1: The reciprocal of the mean safety factor on the axis, 1/q₀(0), and the O-point position r_O, as functions of the applied helical potential ϕ₀ for different aspect ratios R/r_w, with (m, n) = (1, 1). The dependence of these two quantities on ϕ₀ exhibits little sensitivity to R/r_w,more »

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Works referenced in this record:

Electrostatically driven helical plasma state
journal, May 2017

Akçay, Cihan; Finn, John M.; Nebel, Richard A.
Physics of Plasmas, Vol. 24, Issue 5
DOI: 10.1063/1.4981384

Semi-implicit magnetohydrodynamic calculations
journal, June 1987

Schnack, D. D.; Barnes, D. C.; Mikic, Z.
Journal of Computational Physics, Vol. 70, Issue 2
DOI: 10.1016/0021-9991(87)90186-0

Single and multiple helicity Ohmic states in reversed‐field pinches
journal, May 1992

Finn, John M.; Nebel, Rick; Bathke, Charles
Physics of Fluids B: Plasma Physics, Vol. 4, Issue 5
DOI: 10.1063/1.860082

Review of spheromak research
journal, June 1994

Jarboe, T. R.
Plasma Physics and Controlled Fusion, Vol. 36, Issue 6
DOI: 10.1088/0741-3335/36/6/002

Properties of the electrostatically driven helical plasma state
text, January 2017

Akçay, Cihan; Finn, John M.; Nebel, Richard A.
arXiv
DOI: 10.48550/arxiv.1710.03339

Figures / Tables found in this record:

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

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Title: Geometric scalings for the electrostatically driven helical plasma state

Abstract

Citation Formats

Figures / Tables:

Electrostatically driven helical plasma state journal, May 2017

Semi-implicit magnetohydrodynamic calculations journal, June 1987

Single and multiple helicity Ohmic states in reversed‐field pinches journal, May 1992

Review of spheromak research journal, June 1994

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Electrostatically driven helical plasma state
journal, May 2017

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Single and multiple helicity Ohmic states in reversed‐field pinches
journal, May 1992

Review of spheromak research
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Properties of the electrostatically driven helical plasma state
text, January 2017