Skip to main content Accessibility help
×
Home
Hostname: page-component-7ccbd9845f-hl5gf Total loading time: 0.386 Render date: 2023-01-29T02:06:59.150Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true

Effect of sheared E × B flow on the blob dynamics in the scrape-off layer of HL-2A tokamak

Published online by Cambridge University Press:  11 November 2022

W.C. Wang
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
J. Cheng*
Affiliation:
Institute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, PR China
Z.B. Shi
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
L.W. Yan
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
Z.H. Huang
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
N. Wu
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
Q. Zou
Affiliation:
Institute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, PR China
Y.J. Zhu
Affiliation:
Institute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, PR China
X. Chen
Affiliation:
Institute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, PR China
J.Q. Dong
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027, PR China
W.L. Zhong
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
M. Xu
Affiliation:
Southwestern Institute of Physics, Chengdu, Sichuan 610041, PR China
*
Email address for correspondence: chengj@swjtu.edu.cn

Abstract

The effect of sheared E × B flow on the blob dynamics in the scrape-off layer (SOL) of HL-2A tokamak has been studied during the plasma current ramp-up in ohmically heated deuterium plasmas by the combination of poloidal and radial Langmuir probe arrays. The experimental results indicate that the SOL sheared E × B flow is substantially enhanced as the plasma current exceeds a certain value and the strong sheared E × B flow has the ability to slow the blob radial motion via stretching its poloidal correlation length. The locally accumulated blobs are suggested to be responsible for the increase of plasma density just outside the Last Closed Flux Surface (LCFS) observed in this experiment. The results presented here reveal the significant role played by the strong sheared E × B flow on the blob dynamics, which provides a potential method to control the SOL width by modifying the sheared E × B flow in future tokamak plasmas.

Type
Research Article
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Beall, J.M., Kim, Y.C. & Powers, E.J. 1982 Estimation of wavenumber and frequency spectra using fixed probe pairs. J. Appl. Phys. 53, 3933.CrossRefGoogle Scholar
Bisai, N., Das, A., Deshpande, S., Jha, R., Kaw, P., Sen, A. & Singh, R. 2005 Formation of a density blob and its dynamics in the edge and the scrape-off layer of a tokamak plasma. Phys. Plasmas 12, 102515.CrossRefGoogle Scholar
Burrell, K.H. 1998 Turbulence and sheared flow. Science 281, 1816.CrossRefGoogle Scholar
Carralero, D., Manz, P., Aho-Mantila, L., Birkenmeier, G., Brix, M., Groth, M., Müller, H.W., Stroth, U., Vianello, N., Wolfrum, E., ASDEX Upgrade team & JET Contributors 2015 Experimental validation of a filament transport model in turbulent magnetized plasmas. Phys. Rev. Lett. 115, 215002.CrossRefGoogle ScholarPubMed
Carter, T.A. & Maggs, J.E. 2009 Modifications of turbulence and turbulent transport associated with a bias-induced confinement transition in the large plasma device. Phys. Plasmas 16, 012304.CrossRefGoogle Scholar
Cheng, J., Dong, J.Q., Yan, L.W., Itoh, K., Zhao, K.J., Hong, W.Y., Huang, Z.H., Nie, L., Lan, T. & Liu, A.D. 2013 Generation of large-scale coherent structures by turbulence in the edge plasmas of the HL-2A tokamak. Nucl. Fusion 53, 093008.CrossRefGoogle Scholar
D'Ippolito, D.A., Myra, J.R. & Krasheninnikov, S.I. 2002 Cross-field blob transport in tokamak scrape-off-layer plasmas. Phys. Plasmas 9, 222.CrossRefGoogle Scholar
D'Ippolito, D.A., Myra, J.R. & Zweben, S.J. 2011 Convective transport by intermittent blob-filaments: comparison of theory and experiment. Phys. Plasmas 18, 060501.CrossRefGoogle Scholar
Fedorczak, N., Peret, M., Bufferand, H., Ciraolo, G., Ghendrih, P. & Tamain, P. 2019 A spectral filament model for turbulent transport and scrape off layer width in circular geometry. Nucl. Mater. Energy 19, 433.CrossRefGoogle Scholar
Filippas, A.V., Bengston, R.D., Li, G.X., Meier, M., Ritz, C.P. & Powers, E.J. 1995 Conditional analysis of floating potential fluctuations at the edge of the Texas Experimental Tokamak Upgrade (TEXT-U). Phys. Plasmas 2, 839.CrossRefGoogle Scholar
Fuchert, G., Birkenmeier, G., Ramisch, M. & Stroth, U. 2016 Characterization of the blob generation region and blobby transport in a stellarator. Plasma Phys. Control. Fusion 58, 054005.CrossRefGoogle Scholar
Furno, I., Labit, B., Podesta, M., Fasoli, A., Mueller, S.H., Poli, F.M., Ricci, P., Theiler, C., Brunner, S. & Diallo, A. 2008 Experimental observation of the blob-generation mechanism from interchange waves in a plasma. Phys. Rev. Lett. 100, 055004.CrossRefGoogle ScholarPubMed
Garcia, O.E., Horacek, J., Pitts, R.A., Nielsen, A.H., Fundamenski, W., Naulin, V. & Rasmussen, J.J. 2007 a Fluctuations and transport in the TCV scrape-off layer. Nucl. Fusion 47, 667.CrossRefGoogle Scholar
Garcia, O.E., Naulin, V., Nielsen, A.H. & Rasmussen, J.J. 2004 Computations of intermittent transport in scrape-off layer plasmas. Phys. Rev. Lett. 92, 165003.CrossRefGoogle ScholarPubMed
Garcia, O.E., Pitts, R.A., Horacek, J., Madsen, J., Naulin, V., Nielsen, A.H. & Rasmussen, J.J. 2007 b Collisionality dependent transport in TCV SOL plasmas. Plasma Phys. Control. Fusion 49, B47.CrossRefGoogle Scholar
Garcia, O.E., Pitts, R.A., Horacek, J., Nielsen, A.H., Fundamenski, W., Graves, J.P., Naulin, V. & Rasmussen, J.J. 2007 c Turbulent transport in the TCV SOL. J. Nucl. Mater. 363-365, 575.CrossRefGoogle Scholar
Ghendrih, P., Ciraolo, G., Larmande, Y., Sarazin, Y., Tamain, P., Beyer, P., Chiavassa, G., Darmet, G., Garbet, X. & Grandgirard, V. 2009 Shearing effects on density burst propagation in SOL plasmas. J. Nucl. Mater. 390-391, 425.CrossRefGoogle Scholar
Giacomin, M., Stagni, A., Ricci, P., Boedo, J.A., Horacek, J., Reimerdes, H. & Tsui, C.K. 2021 Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges. Nucl. Fusion 61, 076002.CrossRefGoogle Scholar
Grulke, O., Klinger, T., Endler, M. & Piel, A. 2001 Analysis of large-scale fluctuation structures in the scrape-off layer of the Wendelstein 7-AS stellarator. Phys. Plasmas 8, 5171.CrossRefGoogle Scholar
Halpern, F.D., LaBombard, B., Terry, J.L. & Zweben, S.J. 2017 Outer midplane scrape-off layer profiles and turbulence in simulations of Alcator C-Mod inner-wall limited discharges. Phys. Plasmas 24, 072502.CrossRefGoogle Scholar
Happel, T., Greiner, F., Mahdizadeh, N., Nold, B., Ramisch, M. & Stroth, U. 2009 Generation of intermittent turbulent events at the transition from closed to open field lines in a toroidal plasma. Phys. Rev. Lett. 102, 255001.CrossRefGoogle Scholar
Katz, N., Egedal, J., Fox, W., Le, A. & Porkolab, M. 2008 Experiments on the propagation of plasma filaments. Phys. Rev. Lett. 101, 015003.CrossRefGoogle ScholarPubMed
Kirk, A., Thornton, A.J., Harrison, J.R., Militello, F. & Walkden, N.R. 2016 L-mode filament characteristics on MAST as a function of plasma current measured using visible imaging. Plasma Phys. Control. Fusion 58, 085008.CrossRefGoogle Scholar
Krasheninnikov, S.I. 2001 On scrape off layer plasma transport. Phys. Lett. A 283, 368.CrossRefGoogle Scholar
Labombard, B., Boivin, R.L., Greenwald, M., Hughes, J. & Group, A. 2001 Particle transport in the scrape-off layer and its relationship to discharge density limit in Alcator C-Mod. Phys. Plasmas 8, 2107.CrossRefGoogle Scholar
Lin, H., Li, G.X., Bengtson, R.D., Ritz, C.P. & Tsui, H. 1992 A comparison fluctuations of Langmuir probe techniques for measuring temperature. Rev. Sci. Instrum. 63, 4611.CrossRefGoogle Scholar
Militello, F. & Omotani, J.T. 2016 Scrape off layer profiles interpreted with filament dynamics. Nucl. Fusion 56, 104004.CrossRefGoogle Scholar
Myra, J.R., D'Ippolito, D.A., Stotler, D.P., Zweben, S.J., LeBlanc, B.P., Menard, J.E., Maqueda, R.J. & Boedo, J. 2006 a Blob birth and transport in the tokamak edge plasma: analysis of imaging data. Phys. Plasmas 13, 092509.CrossRefGoogle Scholar
Myra, J.R., Russell, D.A. & D'Ippolito, D.A. 2006 b Collisionality and magnetic geometry effects on tokamak edge turbulent transport. I. A two-region model with application to blobs. Phys. Plasmas 13, 112502.CrossRefGoogle Scholar
Offeddu, N., Han, W., Theiler, C., Golfinopoulos, T., Terry, J.L., Marmar, E., Wüthrich, C., Tsui, C.K., de Oliveira, H., Duval, B.P., Galassi, D., Oliveira, D.S., Mancini, D. & the TCV Team 2022 Cross-field and parallel dynamics of SOL filaments in TCV. Nucl. Fusion 62, 096014.CrossRefGoogle Scholar
Russell, D.A., Myra, J.R. & D'Ippolito, D.A. 2007 Collisionality and magnetic geometry effects on tokamak edge turbulent transport. II. Many-blob turbulence in the two-region model. Phys. Plasmas 14, 102307.CrossRefGoogle Scholar
Shesterikov, I., Xu, Y., Hidalgo, C., Berte, M., Dumortier, P., Schoor, M.V., Vergote, M. & Van Oost, G. 2012 Direct evidence of eddy breaking and tilting by edge sheared flows observed in the TEXTOR tokamak. Nucl. Fusion 52, 042004.CrossRefGoogle Scholar
Terry, J.L., Zweben, S.J., Hallatschek, K., LaBombard, B., Maqueda, R.J., Bai, B., Boswell, C.J., Greenwald, M., Kopon, D., Nevins, W.M., Pitcher, C.S., Rogers, B.N., Stotler, D.P. & Xu, X.Q. 2003 Observations of the turbulence in the scrape-off-layer of Alcator C-Mod and comparisons with simulation. Phys. Plasmas 10, 1739.CrossRefGoogle Scholar
Tsui, C.K., Boedo, J.A., Myra, J.R., Duval, B., Labit, B., Theiler, C., Vianello, N., Vijvers, W.A.J., Reimerdes, H., Coda, S., Février, O., Harrison, J.R., Horacek, J., Lipschultz, B., Maurizio, R., Nespoli, F., Sheikh, U., Verhaegh, K. & Walkden, N. 2018 Filamentary velocity scaling validation in the TCV tokamak. Phys. Plasmas 25, 072506.CrossRefGoogle Scholar
Tsui, H.Y.W., Bengtson, R.D., Li, G.X., Lin, H., Meier, M., Ritz, C.P. & Wootton, A.J. 1992 A new scheme for Langmuir probe measurement of transport and electron temperature fluctuations. Rev. Sci. Instrum. 63, 4608.CrossRefGoogle Scholar
Vianello, N., et al. 2019 Scrape-off layer transport and filament characteristics in high-density tokamak regimes. Nucl. Fusion 60, 016001.CrossRefGoogle Scholar
Xu, G.S., Naulin, V., Fundamenski, W., Hidalgo, C., Alonso, J.A., Silva, C., Gonçalves, B., Nielsen, A.H., Juul Rasmussen, J., Krasheninnikov, S.I., Wan, B.N. & Stamp, M. 2009 Blob/hole formation and zonal-flow generation in the edge plasma of the JET tokamak. Nucl. Fusion 49, 092002.CrossRefGoogle Scholar
Xu, Y.H., Jachmich, S., Weynants, R.R. & the TEXTOR team 2005 On the properties of turbulence intermittency in the boundary of the TEXTOR tokamak. Plasma Phys. Control. Fusion 47, 1841.CrossRefGoogle Scholar
Yang, Q.Q., Xu, G., Zhong, F.C., Wang, L., Wang, H.Q., Chen, R., Yan, N., Liu, S.C., Chen, L. & Jia, M.N. 2015 Impact of E × B flow shear on turbulence and resulting power fall-off width in H-mode plasmas in experimental advanced superconducting tokamak. Phys. Plasmas 22, 062504.CrossRefGoogle Scholar
Yu, G.Q. & Krasheninnikov, S.I. 2003 Dynamics of blobs in scrape-off-layer/shadow regions of tokamaks and linear devices. Phys. Plasmas 10, 4413.CrossRefGoogle Scholar
Zhang, W., Cziegier, I., Bobkov, V., Conway, G.D., Fuchert, G., Griener, M., Kardaun, O., Manz, P., Noterdaeme, J.M. & Seliunin, E. 2019 Blob distortion by radio-frequency induced sheared flow. Nucl. Fusion 59, 074001.CrossRefGoogle Scholar
Zweben, S.J., Maqueda, R.J., Stotler, D.P., Keesee, A., Boedo, J., Bush, C.E., Kaye, S.M., LeBlanc, B., Lowrance, J.L., Mastrocola, V.J., Maingi, R., Nishino, N., Renda, G., Swain, D.W., Wilgen, J.B. & the NSTX Team 2003 High-speed imaging of edge turbulence in NSTX. Nucl. Fusion 44, 134.CrossRefGoogle Scholar

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Effect of sheared E × B flow on the blob dynamics in the scrape-off layer of HL-2A tokamak
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Effect of sheared E × B flow on the blob dynamics in the scrape-off layer of HL-2A tokamak
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Effect of sheared E × B flow on the blob dynamics in the scrape-off layer of HL-2A tokamak
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *