Comparison between mirror Langmuir probe and gas-puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer
Abstract
Statistical properties of the scrape-off layer plasma fluctuations are studied in ohmically heated plasmas in the Alcator C-Mod tokamak. For the first time, plasma fluctuations as well as parameters that describe the fluctuations are compared across measurements from a mirror Langmuir probe (MLP) and from gas-puff imaging (GPI) that sample the same plasma discharge. This comparison is complemented by an analysis of line emission time-series data, synthesized from the MLP electron density and temperature measurements. The fluctuations observed by the MLP and GPI typically display relative fluctuation amplitudes of order unity together with positively skewed and flattened probability density functions. Such data time series are well described by an established stochastic framework that models the data as a superposition of uncorrelated, two-sided exponential pulses. The most important parameter of the process is the intermittency parameter, $$γ=τ_d/τ_w$$, where τd denotes the duration time of a single pulse and $$τ_w$$ gives the average waiting time between consecutive pulses. In this study we show, using a new deconvolution method, that these parameters can be consistently estimated from different statistics of the data. We also show that the statistical properties of the data sampled by the MLP and GPI diagnostic are very similar. Finally, a synthetic GPI signal using only plasma parameters sampled by the MLP shows qualitatively different fluctuation statistics from the measured GPI signal.
- Authors:
-
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- UiT The Arctic Univ. of Norway, Tromsø (Norway)
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
- Publication Date:
- Research Org.:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC); Research Council of Norway
- OSTI Identifier:
- 1737827
- Grant/Contract Number:
- FC02-99ER54512; 240510/F20
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Journal of Plasma Physics
- Additional Journal Information:
- Journal Volume: 86; Journal Issue: 5; Journal ID: ISSN 0022-3778
- Publisher:
- Cambridge University Press
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; fusion plasma; plasma diagnostics
Citation Formats
Kube, R., Theodorsen, A., Garcia, O. E., Brunner, D., LaBombard, B., and Terry, J. L. Comparison between mirror Langmuir probe and gas-puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer. United States: N. p., 2020.
Web. doi:10.1017/s0022377820001282.
Kube, R., Theodorsen, A., Garcia, O. E., Brunner, D., LaBombard, B., & Terry, J. L. Comparison between mirror Langmuir probe and gas-puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer. United States. https://doi.org/10.1017/s0022377820001282
Kube, R., Theodorsen, A., Garcia, O. E., Brunner, D., LaBombard, B., and Terry, J. L. Fri .
"Comparison between mirror Langmuir probe and gas-puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer". United States. https://doi.org/10.1017/s0022377820001282. https://www.osti.gov/servlets/purl/1737827.
@article{osti_1737827,
title = {Comparison between mirror Langmuir probe and gas-puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer},
author = {Kube, R. and Theodorsen, A. and Garcia, O. E. and Brunner, D. and LaBombard, B. and Terry, J. L.},
abstractNote = {Statistical properties of the scrape-off layer plasma fluctuations are studied in ohmically heated plasmas in the Alcator C-Mod tokamak. For the first time, plasma fluctuations as well as parameters that describe the fluctuations are compared across measurements from a mirror Langmuir probe (MLP) and from gas-puff imaging (GPI) that sample the same plasma discharge. This comparison is complemented by an analysis of line emission time-series data, synthesized from the MLP electron density and temperature measurements. The fluctuations observed by the MLP and GPI typically display relative fluctuation amplitudes of order unity together with positively skewed and flattened probability density functions. Such data time series are well described by an established stochastic framework that models the data as a superposition of uncorrelated, two-sided exponential pulses. The most important parameter of the process is the intermittency parameter, $γ=τ_d/τ_w$, where τd denotes the duration time of a single pulse and $τ_w$ gives the average waiting time between consecutive pulses. In this study we show, using a new deconvolution method, that these parameters can be consistently estimated from different statistics of the data. We also show that the statistical properties of the data sampled by the MLP and GPI diagnostic are very similar. Finally, a synthetic GPI signal using only plasma parameters sampled by the MLP shows qualitatively different fluctuation statistics from the measured GPI signal.},
doi = {10.1017/s0022377820001282},
journal = {Journal of Plasma Physics},
number = 5,
volume = 86,
place = {United States},
year = {Fri Oct 30 00:00:00 EDT 2020},
month = {Fri Oct 30 00:00:00 EDT 2020}
}
Works referenced in this record:
Transport-driven Scrape-Off-Layer flows and the boundary conditions imposed at the magnetic separatrix in a tokamak plasma
journal, September 2004
- LaBombard, B.; Rice, J. E.; Hubbard, A. E.
- Nuclear Fusion, Vol. 44, Issue 10
Hybrid time dependent/independent solution for the He I line ratio temperature and density diagnostic for a thermal helium beam with applications in the scrape-off layer-edge regions in tokamaks
journal, January 2012
- Muñoz Burgos, J. M.; Schmitz, O.; Loch, S. D.
- Physics of Plasmas, Vol. 19, Issue 1
Comparison of 3D flux-driven scrape-off layer turbulence simulations with gas-puff imaging of Alcator C-Mod inner-wall limited discharges
journal, April 2015
- Halpern, F. D.; Terry, J. L.; Zweben, S. J.
- Plasma Physics and Controlled Fusion, Vol. 57, Issue 5
Edge turbulence imaging in the Alcator C-Mod tokamak
journal, May 2002
- Zweben, S. J.; Stotler, D. P.; Terry, J. L.
- Physics of Plasmas, Vol. 9, Issue 5
Reconstruction of current profile parameters and plasma shapes in tokamaks
journal, November 1985
- Lao, L. L.; St. John, H.; Stambaugh, R. D.
- Nuclear Fusion, Vol. 25, Issue 11
Visible imaging of turbulence in the SOL of the Alcator C-Mod tokamak
journal, March 2001
- Terry, J. L.; Maqueda, R.; Pitcher, C. S.
- Journal of Nuclear Materials, Vol. 290-293
The influence of blobs on neutral particles in the scrape-off layer
journal, March 2016
- Thrysøe, Alexander S.; Tophøj, Laust E. H.; Naulin, Volker
- Plasma Physics and Controlled Fusion, Vol. 58, Issue 4
Plasma fluctuations in the scrape-off layer and at the divertor target in Alcator C-Mod and their relationship to divertor collisionality and density shoulder formation
journal, May 2019
- Kuang, A. Q.; LaBombard, B.; Brunner, D.
- Nuclear Materials and Energy, Vol. 19
Fluctuations and transport in the TCV scrape-off layer
journal, June 2007
- Garcia, O. E.; Horacek, J.; Pitts, R. A.
- Nuclear Fusion, Vol. 47, Issue 7
Overview of edge electrostatic turbulence experiments on TCV
journal, March 2005
- Horacek, J.; Pitts, R. A.; Graves, J. P.
- Czechoslovak Journal of Physics, Vol. 55, Issue 3
Burst statistics in Alcator C-Mod SOL turbulence
journal, July 2013
- Garcia, O. E.; Cziegler, I.; Kube, R.
- Journal of Nuclear Materials, Vol. 438
Intermittent fluctuations in the Alcator C-Mod scrape-off layer
journal, May 2013
- Garcia, O. E.; Fritzner, S. M.; Kube, R.
- Physics of Plasmas, Vol. 20, Issue 5
Richardson-Lucy Deblurring for Scenes under a Projective Motion Path
journal, August 2011
- Yu-Wing Tai, ; Brown, M. S.
- IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 33, Issue 8
Density limits in toroidal plasmas
journal, July 2002
- Greenwald, Martin
- Plasma Physics and Controlled Fusion, Vol. 44, Issue 8
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
An experimental investigation of the high density transition of the scrape-off layer transport in ASDEX Upgrade
journal, November 2014
- Carralero, D.; Birkenmeier, G.; Müller, H. W.
- Nuclear Fusion, Vol. 54, Issue 12
Intermittent transport in the plasma periphery of the T-10 tokamak
journal, March 2004
- Kirnev, G. S.; Budaev, V. P.; Grashin, S. A.
- Plasma Physics and Controlled Fusion, Vol. 46, Issue 4
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
Relationship between frequency power spectra and intermittent, large-amplitude bursts in the Alcator C-Mod scrape-off layer
journal, August 2017
- Theodorsen, A.; Garcia, O. E.; Kube, R.
- Nuclear Fusion, Vol. 57, Issue 11
Scrape-off layer turbulence in TCV: evidence in support of stochastic modelling
journal, January 2016
- Theodorsen, A.; Garcia, O. E.; Horacek, J.
- Plasma Physics and Controlled Fusion, Vol. 58, Issue 4
Neutral Gas Transport Modeling with DEGAS 2
journal, January 1994
- Stotler, Daren; Karney, Charles
- Contributions to Plasma Physics, Vol. 34, Issue 2-3
Statistical properties of the plasma fluctuations and turbulent cross-field fluxes in the outboard mid-plane scrape-off layer of Alcator C-Mod
journal, January 2019
- Kube, R.; Garcia, O. E.; Theodorsen, A.
- Nuclear Materials and Energy, Vol. 18
Stochastic modelling of intermittent fluctuations in the scrape-off layer: Correlations, distributions, level crossings, and moment estimation
journal, May 2016
- Garcia, O. E.; Kube, R.; Theodorsen, A.
- Physics of Plasmas, Vol. 23, Issue 5
Auto-correlation function and frequency spectrum due to a super-position of uncorrelated exponential pulses
journal, March 2017
- Garcia, O. E.; Theodorsen, A.
- Physics of Plasmas, Vol. 24, Issue 3
Transport by intermittency in the boundary of the DIII-D tokamak
journal, May 2003
- Boedo, J. A.; Rudakov, D. L.; Moyer, R. A.
- Physics of Plasmas, Vol. 10, Issue 5
Universality of Poisson-driven plasma fluctuations in the Alcator C-Mod scrape-off layer
journal, December 2018
- Theodorsen, A.; Garcia, O. E.; Kube, R.
- Physics of Plasmas, Vol. 25, Issue 12
Experimental studies of edge turbulence and confinement in Alcator C-Mod
journal, May 2010
- Cziegler, I.; Terry, J. L.; Hughes, J. W.
- Physics of Plasmas, Vol. 17, Issue 5
Intermittent fluctuations in the TCV scrape-off layer
journal, May 2015
- Garcia, O. E.; Horacek, J.; Pitts, R. A.
- Nuclear Fusion, Vol. 55, Issue 6
An Iterative Image Space Reconstruction Algorthm Suitable for Volume ECT
journal, June 1986
- Daube-Witherspoon, Margaret E.; Muehllehner, Gerd
- IEEE Transactions on Medical Imaging, Vol. 5, Issue 2
Fast piezoelectric valve offering controlled gas injection in magnetically confined fusion plasmas for diagnostic and fuelling purposes
journal, March 2017
- Griener, M.; Schmitz, O.; Bald, K.
- Review of Scientific Instruments, Vol. 88, Issue 3
Experimental investigation of the parallel structure of fluctuations in the scrape-off layer of Alcator C-Mod
journal, March 2014
- Grulke, O.; Terry, J. L.; Cziegler, I.
- Nuclear Fusion, Vol. 54, Issue 4
Impact of neutral density fluctuations on gas puff imaging diagnostics
journal, August 2017
- Wersal, C.; Ricci, P.
- Nuclear Fusion, Vol. 57, Issue 11
Statistical analysis of the ion flux to the JET outer wall
journal, January 2017
- Walkden, N. R.; Wynn, A.; Militello, F.
- Nuclear Fusion, Vol. 57, Issue 3
Scrape off layer profiles interpreted with filament dynamics
journal, August 2016
- Militello, F.; Omotani, J. T.
- Nuclear Fusion, Vol. 56, Issue 10
Statistical properties of a filtered Poisson process with additive random noise: distributions, correlations and moment estimation
journal, April 2017
- Theodorsen, A.; Garcia, O. E.; Rypdal, M.
- Physica Scripta, Vol. 92, Issue 5
Fluctuation statistics in the scrape-off layer of Alcator C-Mod
journal, March 2016
- Kube, R.; Theodorsen, A.; Garcia, O. E.
- Plasma Physics and Controlled Fusion, Vol. 58, Issue 5
Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak
dataset, January 2018
- D. Brunner, A. Q. Kuang
- Harvard Dataverse
SOL width and intermittent fluctuations in KSTAR
journal, August 2017
- Garcia, O. E.; Kube, R.; Theodorsen, A.
- Nuclear Materials and Energy, Vol. 12
Stochastic Modeling of Intermittent Scrape-Off Layer Plasma Fluctuations
journal, June 2012
- Garcia, O. E.
- Physical Review Letters, Vol. 108, Issue 26
A Model-Based Deconvolution Approach to Solve Fiber Crossing in Diffusion-Weighted MR Imaging
journal, March 2007
- Dell'Acqua, Flavio; Rizzo, Giovanna; Scifo, Paola
- IEEE Transactions on Biomedical Engineering, Vol. 54, Issue 3
Qualification and implementation of line ratio spectroscopy on helium as plasma edge diagnostic at ASDEX Upgrade
journal, December 2017
- Griener, M.; Burgos, J. M. Muñoz; Cavedon, M.
- Plasma Physics and Controlled Fusion, Vol. 60, Issue 2
Experimental investigation of transport phenomena in the scrape-off layer and divertor
journal, February 1997
- LaBombard, B.
- Journal of Nuclear Materials, Vol. 241-243, Issue 1
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
Particle transport in the scrape-off layer and its relationship to discharge density limit in Alcator C-Mod
journal, May 2001
- LaBombard, B.; Boivin, R. L.; Greenwald, M.
- Physics of Plasmas, Vol. 8, Issue 5
New insights on boundary plasma turbulence and the quasi-coherent mode in Alcator C-Mod using a Mirror Langmuir Probe
journal, May 2014
- LaBombard, B.; Golfinopoulos, T.; Terry, J. L.
- Physics of Plasmas, Vol. 21, Issue 5
Level crossings, excess times, and transient plasma–wall interactions in fusion plasmas
journal, April 2016
- Theodorsen, A.; Garcia, O. E.
- Physics of Plasmas, Vol. 23, Issue 4
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
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
Blob properties in L- and H-mode from gas-puff imaging in ASDEX upgrade
journal, October 2014
- Fuchert, G.; Birkenmeier, G.; Carralero, D.
- Plasma Physics and Controlled Fusion, Vol. 56, Issue 12
Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak
journal, July 2017
- Brunner, D.; Kuang, A. Q.; LaBombard, B.
- Review of Scientific Instruments, Vol. 88, Issue 7
Self-similar density turbulence in the TCV tokamak scrape-off layer
journal, February 2005
- Graves, J. P.; Horacek, J.; Pitts, R. A.
- Plasma Physics and Controlled Fusion, Vol. 47, Issue 3
Mirror Langmuir probe: A technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode
journal, July 2007
- LaBombard, B.; Lyons, L.
- Review of Scientific Instruments, Vol. 78, Issue 7
Statistical features of coherent structures at increasing magnetic field pitch investigated using fast imaging in QUEST
journal, November 2012
- Banerjee, Santanu; Zushi, H.; Nishino, N.
- Nuclear Fusion, Vol. 52, Issue 12
Neutral transport simulations of gas puff imaging experiments
journal, March 2003
- Stotler, D.; Labombard, B.; Terry, J.
- Journal of Nuclear Materials, Vol. 313-316
An iterative technique for the rectification of observed distributions
journal, June 1974
- Lucy, L. B.
- The Astronomical Journal, Vol. 79
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