Geometric scalings for the electrostatically driven helical plasma state

Journal Article · Wed Dec 27 00:00:00 EST 2017 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.5011774· OSTI ID:1524594

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

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

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 $(m,n)=(2,1)$.

• Research Organization: Tibbar Plasma Technologies, Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: AR0000677
• OSTI ID: 1524594
• Alternate ID(s): OSTI ID: 1414984
• Journal Information: Physics of Plasmas, Vol. 24, Issue 12; ISSN 1070-664X
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY