Scaling of spoke rotation frequency within a Penning discharge

doi:10.1063/1.5038733

Title: Scaling of spoke rotation frequency within a Penning discharge

Full Record
Other Related Research

Abstract

A rotating plasma spoke is shown to develop in two-dimensional full-sized kinetic simulations of a Penning discharge cross-section. Electron cross-field transport within the discharge is highly anomalous and correlates strongly with the spoke phase. Similarity between collisional and collisionless simulations demonstrates that ionization is not necessary for spoke formation. Parameter scans with discharge current I_d, applied magnetic field strength B, and ion mass m_i show that the spoke frequency scales with √ eE_rL_n/m_i, where E_r is the radial electric field, L_n is the gradient length scale, and e is the fundamental charge. As a result, this scaling suggests that the spoke may develop as a non-linear phase of the collisionless Simon-Hoh instability.

Authors:

Powis, Andrew T. ^[1];

^[2];

^[3]

Princeton Univ., Princeton, NJ (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Univ. of Saskatchewan, Saskatoon, SK (Canada)

Publication Date:: 2018-07-12

Research Org.:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1543871

Grant/Contract Number:: AC02-05CH11231

Resource Type:: Accepted Manuscript

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 25; Journal Issue: 7; 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; Physics

Citation Formats


                    Powis, Andrew T., Carlsson, Johan A., Kaganovich, Igor D., Raitses, Yevgeny, and Smolyakov, Andrei. Scaling of spoke rotation frequency within a Penning discharge.  United States: N. p., 2018. 
        Web.  doi:10.1063/1.5038733.

Copy to clipboard


                    Powis, Andrew T., Carlsson, Johan A., Kaganovich, Igor D., Raitses, Yevgeny, & Smolyakov, Andrei. Scaling of spoke rotation frequency within a Penning discharge.  United States.  doi:10.1063/1.5038733.

Copy to clipboard


                    Powis, Andrew T., Carlsson, Johan A., Kaganovich, Igor D., Raitses, Yevgeny, and Smolyakov, Andrei. Thu .  
        "Scaling of spoke rotation frequency within a Penning discharge".  United States.  doi:10.1063/1.5038733.  https://www.osti.gov/servlets/purl/1543871.

Copy to clipboard


                    
@article{osti_1543871,

  title        = {Scaling of spoke rotation frequency within a Penning discharge},

  author       = {Powis, Andrew T. and Carlsson, Johan A. and Kaganovich, Igor D. and Raitses, Yevgeny and Smolyakov, Andrei},

  abstractNote = {A rotating plasma spoke is shown to develop in two-dimensional full-sized kinetic simulations of a Penning discharge cross-section. Electron cross-field transport within the discharge is highly anomalous and correlates strongly with the spoke phase. Similarity between collisional and collisionless simulations demonstrates that ionization is not necessary for spoke formation. Parameter scans with discharge current Id, applied magnetic field strength B, and ion mass mi show that the spoke frequency scales with √eErLn/mi, where Er is the radial electric field, Ln is the gradient length scale, and e is the fundamental charge. As a result, this scaling suggests that the spoke may develop as a non-linear phase of the collisionless Simon-Hoh instability.},

  doi          = {10.1063/1.5038733},

  journal      = {Physics of Plasmas},

  number       = 7,

  volume       = 25,

  place        = {United States},

  year         = {2018},

  month        = {7}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

DOI: 10.1063/1.5038733

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 5 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Particle-in-cell simulations of anomalous transport in a Penning discharge

Journal Article Carlsson, Johan ; Kaganovich, Igor ; Powis, Andrew ; ... - Physics of Plasmas

Electrostatic particle-in-cell simulations of a Penning discharge are performed in order to investigate azimuthally asymmetric, spoke-like structures previously observed in experiments. Two-dimensional simulations show that for Penning-discharge conditions, a persistent nonlinear spoke-like structure forms readily and rotates in the direction of E × B and electron diamagnetic drifts. The azimuthal velocity is within about a factor of 2 of the ion acoustic speed. The spoke frequency follows the experimentally observed scaling with ion mass, which indicates the importance of ion inertia in spoke formation. The spoke provides enhanced (anomalous) radial electron transport, and the effective cross-field conductivity is several timesmore »« less
Cited by 5
DOI: 10.1063/1.5017467

Full Text Available
Dimensionless size scaling of intrinsic rotation in DIII-D

Journal Article deGrassie, John S. ; Solomon, Wayne M. ; Rice, J. E. ; ... - Physics of Plasmas

A dimensionless empirical scaling for intrinsic toroidal rotation is given; M _A ~β _Nρ*, where M _A is the toroidal velocity divided by the Alfvén velocity, β _N the usual normalized β value, and ρ* is the ion gyroradius divided by the minor radius. This scaling describes well experimental data from DIII-D, and also some published data from C-Mod and JET. The velocity used in this scaling is in an outer location in minor radius, outside of the interior core and inside of the large gradient edge region in H-mode conditions. Furthermore, this scaling establishes the basic magnitude of themore »« less
Cited by 2
DOI: 10.1063/1.4960023

Full Text Available
A multi-machine scaling of halo current rotation

Journal Article Myers, C. E. ; Eidietis, N. W. ; Gerasimov, S. N. ; ... - Nuclear Fusion

Halo currents generated during unmitigated tokamak disruptions are known to develop rotating asymmetric features that are of great concern to ITER because they can dynamically amplify the mechanical stresses on the machine. This paper presents a multi-machine analysis of these phenomena. More specifically, data from C-Mod, NSTX, ASDEX Upgrade, DIII-D, and JET are used to develop empirical scalings of three key quantities: the machine-specific minimum current quench time,more »« less
Cited by 1
DOI: 10.1088/1741-4326/aa958b

Full Text Available
Understanding and predicting profile structure and parametric scaling of intrinsic rotation

Journal Article Wang, W. X. ; Grierson, B. A. ; Ethier, S. ; ... - Physics of Plasmas

This study reports on a recent advance in developing physical understanding and a first-principles-based model for predicting intrinsic rotation profiles in magnetic fusion experiments. It is shown for the first time that turbulent fluctuation-driven residual stress (a non-diffusive component of momentum flux) along with diffusive momentum flux can account for both the shape and magnitude of the observed intrinsic toroidal rotation profile. Both the turbulence intensity gradient and zonal flow E×B shear are identified as major contributors to the generation of the k _∥-asymmetry needed for the residual stress generation. The model predictions of core rotation based on global gyrokineticmore »« less
Cited by 2
DOI: 10.1063/1.4997789

Full Text Available
Optical–SZE scaling relations for DES optically selected clusters within the SPT-SZ Survey

Journal Article Saro, A. ; Bocquet, S. ; Mohr, J. ; ... - Monthly Notices of the Royal Astronomical Society

We study the Sunyaev-Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 degmore »« less
Cited by 1
DOI: 10.1093/mnras/stx594

Full Text Available

Similar Records