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Title: Disconnection of scrape off layer turbulence between the outer midplane and divertor target plate in NSTX

Abstract

The connection between scrape off layer (SOL) turbulence at the outer midplane and at the divertor target plate is characterized in the National Spherical Torus Experiment (NSTX). In this work, divertor fluctuations due to midplane blobs are studied by imaging their helical intersection with the divertor plate. Divertor fluctuation levels gradually decrease approaching the outer strike point. Divertor radial turbulence scale lengths as well as radial and poloidal turbulence propagation velocities are comparable to those on the low field side midplane. Strong correlation between divertor and midplane turbulence is observed in the far SOL. The correlation progressively decreases towards the separatrix, along with the decrease in the measured divertor fluctuations. The reduction in correlation is consistent with an electrostatic two-region blob model with perpendicular ion polarization currents due to X-point geometry causing filament disconnection.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3];  [4]; ORCiD logo [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Lodestar Research Corporation, Boulder, CO (United States)
  4. X Science LLC, Plainsboro, NJ (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1643699
Alternate Identifier(s):
OSTI ID: 1642353
Report Number(s):
LLNL-JRNL-774768
Journal ID: ISSN 0029-5515; TRN: US2201961
Grant/Contract Number:  
AC02-09CH11466; AC52-07NA27344; FG02-97ER54392
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 60; Journal Issue: 2; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Scotti, F., Zweben, S., Myra, J., Maqueda, R., and Soukhanovskii, V. Disconnection of scrape off layer turbulence between the outer midplane and divertor target plate in NSTX. United States: N. p., 2019. Web. doi:10.1088/1741-4326/ab5886.
Scotti, F., Zweben, S., Myra, J., Maqueda, R., & Soukhanovskii, V. Disconnection of scrape off layer turbulence between the outer midplane and divertor target plate in NSTX. United States. https://doi.org/10.1088/1741-4326/ab5886
Scotti, F., Zweben, S., Myra, J., Maqueda, R., and Soukhanovskii, V. Wed . "Disconnection of scrape off layer turbulence between the outer midplane and divertor target plate in NSTX". United States. https://doi.org/10.1088/1741-4326/ab5886. https://www.osti.gov/servlets/purl/1643699.
@article{osti_1643699,
title = {Disconnection of scrape off layer turbulence between the outer midplane and divertor target plate in NSTX},
author = {Scotti, F. and Zweben, S. and Myra, J. and Maqueda, R. and Soukhanovskii, V.},
abstractNote = {The connection between scrape off layer (SOL) turbulence at the outer midplane and at the divertor target plate is characterized in the National Spherical Torus Experiment (NSTX). In this work, divertor fluctuations due to midplane blobs are studied by imaging their helical intersection with the divertor plate. Divertor fluctuation levels gradually decrease approaching the outer strike point. Divertor radial turbulence scale lengths as well as radial and poloidal turbulence propagation velocities are comparable to those on the low field side midplane. Strong correlation between divertor and midplane turbulence is observed in the far SOL. The correlation progressively decreases towards the separatrix, along with the decrease in the measured divertor fluctuations. The reduction in correlation is consistent with an electrostatic two-region blob model with perpendicular ion polarization currents due to X-point geometry causing filament disconnection.},
doi = {10.1088/1741-4326/ab5886},
journal = {Nuclear Fusion},
number = 2,
volume = 60,
place = {United States},
year = {Wed Dec 18 00:00:00 EST 2019},
month = {Wed Dec 18 00:00:00 EST 2019}
}

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Works referenced in this record:

Radial resolution enhancement of the NSTX Thomson scattering diagnostic
journal, October 2012

  • LeBlanc, B. P.; Diallo, A.; Labik, G.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4738655

Edge transport studies in the edge and scrape-off layer of the National Spherical Torus Experiment with Langmuir probes
journal, April 2014

  • Boedo, J. A.; Myra, J. R.; Zweben, S.
  • Physics of Plasmas, Vol. 21, Issue 4
  • DOI: 10.1063/1.4873390

Edge turbulence and SOL transport in tokamaks
journal, June 2009


Investigation into the formation of the scrape-off layer density shoulder in JET ITER-like wall L-mode and H-mode plasmas
journal, February 2018


Edge and SOL turbulence and blob variations over a large database in NSTX
journal, September 2015


Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus Experiment divertor
journal, October 2012

  • Scotti, Filippo; Roquemore, A. L.; Soukhanovskii, V. A.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4739510

Filamentary velocity scaling validation in the TCV tokamak
journal, July 2018

  • Tsui, C. K.; Boedo, J. A.; Myra, J. R.
  • Physics of Plasmas, Vol. 25, Issue 7
  • DOI: 10.1063/1.5038019

Collisionality and magnetic geometry effects on tokamak edge turbulent transport. I. A two-region model with application to blobs
journal, November 2006

  • Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.
  • Physics of Plasmas, Vol. 13, Issue 11
  • DOI: 10.1063/1.2364858

Recent theoretical progress in understanding coherent structures in edge and SOL turbulence
journal, October 2008

  • Krasheninnikov, S. I.; D'Ippolito, D. A.; Myra, J. R.
  • Journal of Plasma Physics, Vol. 74, Issue 5
  • DOI: 10.1017/S0022377807006940

Intermittent electron density and temperature fluctuations and associated fluxes in the Alcator C-Mod scrape-off layer
journal, April 2018

  • Kube, R.; Garcia, O. E.; Theodorsen, A.
  • Plasma Physics and Controlled Fusion, Vol. 60, Issue 6
  • DOI: 10.1088/1361-6587/aab726

Fast imaging of filaments in the X-point region of Alcator C-Mod
journal, August 2017


Statistical properties of electrostatic turbulence in toroidal magnetized plasmas
journal, November 2007


Penetration of filamentary structures into the divertor region of spherical tokamaks
journal, February 2019

  • Baver, D. A.; Myra, J. R.
  • Physics of Plasmas, Vol. 26, Issue 2
  • DOI: 10.1063/1.5065390

Blob structure and motion in the edge and SOL of NSTX
journal, January 2016

  • Zweben, S. J.; Myra, J. R.; Davis, W. M.
  • Plasma Physics and Controlled Fusion, Vol. 58, Issue 4, Article No. 044007
  • DOI: 10.1088/0741-3335/58/4/044007

X -Point Effect on Plasma Blob Dynamics
journal, March 2016


Transport by intermittent convection in the boundary of the DIII-D tokamak
journal, November 2001

  • Boedo, J. A.; Rudakov, D.; Moyer, R.
  • Physics of Plasmas, Vol. 8, Issue 11
  • DOI: 10.1063/1.1406940

Assessing material migration through 13C injection experiments
journal, August 2011


High-speed imaging of edge turbulence in NSTX
journal, December 2003


Filament structures at the plasma edge on MAST
journal, November 2006


Modification of SOL profiles and fluctuations with line-average density and divertor flux expansion in TCV
journal, August 2017


Experimental investigation of the parallel structure of fluctuations in the scrape-off layer of Alcator C-Mod
journal, March 2014


Effect of the magnetic field geometry on the flute-like perturbations near the divertor X point
journal, September 1993


Experimental Validation of a Filament Transport Model in Turbulent Magnetized Plasmas
journal, November 2015


Simulation of turbulence in the divertor region of tokamak edge plasma
journal, March 2005


Turbulence in the Divertor Region of Tokamak Edge Plasma
journal, April 2004

  • Umansky, M. V.; Rognlien, T. D.; Xu, X. Q.
  • Contributions to Plasma Physics, Vol. 44, Issue 13
  • DOI: 10.1002/ctpp.200410025

Direct observations of L-I-H and H-I-L transitions with the X-point reciprocating probe in ASDEX Upgrade
journal, April 2014

  • Müller, S. H.; Conway, G. D.; Birkenmeier, G.
  • Physics of Plasmas, Vol. 21, Issue 4
  • DOI: 10.1063/1.4870012

High density Langmuir probe array for NSTX scrape-off layer measurements under lithiated divertor conditions
journal, October 2010

  • Kallman, J.; Jaworski, M. A.; Kaita, R.
  • Review of Scientific Instruments, Vol. 81, Issue 10
  • DOI: 10.1063/1.3494381

SOL width and intermittent fluctuations in KSTAR
journal, August 2017


Stochastic Modeling of Intermittent Scrape-Off Layer Plasma Fluctuations
journal, June 2012


Divertor leg filaments in NSTX-U
journal, October 2018


Edge instability regimes with applications to blob transport and the quasicoherent mode
journal, September 2005

  • Myra, J. R.; D’Ippolito, D. A.
  • Physics of Plasmas, Vol. 12, Issue 9
  • DOI: 10.1063/1.2048847

Invited Review Article: Gas puff imaging diagnostics of edge plasma turbulence in magnetic fusion devices
journal, April 2017

  • Zweben, S. J.; Terry, J. L.; Stotler, D. P.
  • Review of Scientific Instruments, Vol. 88, Issue 4
  • DOI: 10.1063/1.4981873

Heuristic drift-based model of the power scrape-off width in low-gas-puff H-mode tokamaks
journal, December 2011


Interchange turbulence in the TCV scrape-off layer
journal, December 2005


The appearance and propagation of filaments in the private flux region in Mega Amp Spherical Tokamak
journal, September 2015

  • Harrison, J. R.; Fishpool, G. M.; Thornton, A. J.
  • Physics of Plasmas, Vol. 22, Issue 9
  • DOI: 10.1063/1.4929924

Scaling of the tokamak near the scrape-off layer H-mode power width and implications for ITER
journal, August 2013


Fluctuation-driven transport in the DIII-D boundary
journal, May 2002

  • Rudakov, D. L.; Boedo, J. A.; Moyer, R. A.
  • Plasma Physics and Controlled Fusion, Vol. 44, Issue 6
  • DOI: 10.1088/0741-3335/44/6/308

Observations of the turbulence in the scrape-off-layer of Alcator C-Mod and comparisons with simulation
journal, May 2003

  • Terry, J. L.; Zweben, S. J.; Hallatschek, K.
  • Physics of Plasmas, Vol. 10, Issue 5
  • DOI: 10.1063/1.1564090

Two-dimensional turbulence cross-correlation functions in the edge of NSTX
journal, October 2017

  • Zweben, S. J.; Stotler, D. P.; Scotti, F.
  • Physics of Plasmas, Vol. 24, Issue 10
  • DOI: 10.1063/1.5002695

Self-similar density turbulence in the TCV tokamak scrape-off layer
journal, February 2005


Lithium sputtering from lithium-coated plasma facing components in the NSTX divertor
journal, August 2015


Spatial structure of scrape-off-layer filaments near the midplane and X-point regions of Alcator-C-Mod
journal, June 2009


The poloidal distribution of turbulent fluctuations in the Mega-Ampère Spherical Tokamak
journal, March 2005

  • Antar, G. Y.; Counsell, G.; Ahn, J. -W.
  • Physics of Plasmas, Vol. 12, Issue 3
  • DOI: 10.1063/1.1861894

Latest investigations on fluctuations, ELM filaments and turbulent transport in the SOL of ASDEX Upgrade
journal, June 2011


Tomographic reconstruction of tokamak edge turbulence from single visible camera data and automatic turbulence structure tracking
journal, April 2019


Convective transport by intermittent blob-filaments: Comparison of theory and experiment
journal, June 2011

  • D’Ippolito, D. A.; Myra, J. R.; Zweben, S. J.
  • Physics of Plasmas, Vol. 18, Issue 6
  • DOI: 10.1063/1.3594609

Experimental validation of a filament transport model in turbulent magnetized plasmas
text, January 2015


SOL width and intermittent fluctuations in KSTAR
preprint, January 2016