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Title: Stationarity of I-mode operation and I-mode divertor heat fluxes on the ASDEX Upgrade tokamak

Abstract

Recent I-mode investigations from the ASDEX Upgrade tokamak are reported. It is shown that neutral-beam-injection heated I-modes can be stationary, which is important in terms of extrapolability towards future fusion devices. Furthermore, detailed studies on the weakly coherent mode are reported. In particular, experimental observations point towards its existence in L-mode, before I-mode starts. Moreover, its impact on density and temperature fluctuations is evaluated. Studies of stationary divertor heat fluxes show that in I-mode, the upstream power fall-off length is between those observed in L-mode and H-mode, and it is connected to the scrape-off layer temperature fall-off length. Moreover, analysis of transient divertor heat loads shows that intermittent turbulent events, observed in the confinement region and linked to the weakly coherent mode, are responsible for a significant part of divertor heat loads.

Authors:
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Publication Date:
Research Org.:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sponsoring Org.:
USDOE Office of Science (SC); Euratom research and training programme
Contributing Org.:
ASDEX Upgrade Team; EUROfusion MST1 Team
OSTI Identifier:
1488868
Alternate Identifier(s):
OSTI ID: 1610856
Grant/Contract Number:  
SC0006419; SC0017381; 633053
Resource Type:
Published Article
Journal Name:
Nuclear Materials and Energy
Additional Journal Information:
Journal Name: Nuclear Materials and Energy Journal Volume: 18 Journal Issue: C; Journal ID: ISSN 2352-1791
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Nuclear Science & Technology

Citation Formats

Happel, T., Griener, M., Silvagni, D., Freethy, S. J., Hennequin, P., Janky, F., Manz, P., Prisiazhniuk, D., Ryter, F., Bernert, M., Brida, D., Eich, T., Faitsch, M., Gil, L., Guimarais, L., Merle, A., Nille, D., Pinzón, J., Sieglin, B., Stroth, U., and Viezzer, E. Stationarity of I-mode operation and I-mode divertor heat fluxes on the ASDEX Upgrade tokamak. Netherlands: N. p., 2019. Web. https://doi.org/10.1016/j.nme.2018.12.022.
Happel, T., Griener, M., Silvagni, D., Freethy, S. J., Hennequin, P., Janky, F., Manz, P., Prisiazhniuk, D., Ryter, F., Bernert, M., Brida, D., Eich, T., Faitsch, M., Gil, L., Guimarais, L., Merle, A., Nille, D., Pinzón, J., Sieglin, B., Stroth, U., & Viezzer, E. Stationarity of I-mode operation and I-mode divertor heat fluxes on the ASDEX Upgrade tokamak. Netherlands. https://doi.org/10.1016/j.nme.2018.12.022
Happel, T., Griener, M., Silvagni, D., Freethy, S. J., Hennequin, P., Janky, F., Manz, P., Prisiazhniuk, D., Ryter, F., Bernert, M., Brida, D., Eich, T., Faitsch, M., Gil, L., Guimarais, L., Merle, A., Nille, D., Pinzón, J., Sieglin, B., Stroth, U., and Viezzer, E. Tue . "Stationarity of I-mode operation and I-mode divertor heat fluxes on the ASDEX Upgrade tokamak". Netherlands. https://doi.org/10.1016/j.nme.2018.12.022.
@article{osti_1488868,
title = {Stationarity of I-mode operation and I-mode divertor heat fluxes on the ASDEX Upgrade tokamak},
author = {Happel, T. and Griener, M. and Silvagni, D. and Freethy, S. J. and Hennequin, P. and Janky, F. and Manz, P. and Prisiazhniuk, D. and Ryter, F. and Bernert, M. and Brida, D. and Eich, T. and Faitsch, M. and Gil, L. and Guimarais, L. and Merle, A. and Nille, D. and Pinzón, J. and Sieglin, B. and Stroth, U. and Viezzer, E.},
abstractNote = {Recent I-mode investigations from the ASDEX Upgrade tokamak are reported. It is shown that neutral-beam-injection heated I-modes can be stationary, which is important in terms of extrapolability towards future fusion devices. Furthermore, detailed studies on the weakly coherent mode are reported. In particular, experimental observations point towards its existence in L-mode, before I-mode starts. Moreover, its impact on density and temperature fluctuations is evaluated. Studies of stationary divertor heat fluxes show that in I-mode, the upstream power fall-off length is between those observed in L-mode and H-mode, and it is connected to the scrape-off layer temperature fall-off length. Moreover, analysis of transient divertor heat loads shows that intermittent turbulent events, observed in the confinement region and linked to the weakly coherent mode, are responsible for a significant part of divertor heat loads.},
doi = {10.1016/j.nme.2018.12.022},
journal = {Nuclear Materials and Energy},
number = C,
volume = 18,
place = {Netherlands},
year = {2019},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1016/j.nme.2018.12.022

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Cited by: 6 works
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Works referenced in this record:

Multi-machine scaling of the divertor peak heat flux and width for L-mode and H-mode discharges
journal, March 1999


Change of the scrape-off layer power width with the toroidal B-field direction in ASDEX upgrade
journal, May 2015


Particle transport analysis of the density build-up after the L–H transition in ASDEX Upgrade
journal, August 2013


The physics mechanisms of the weakly coherent mode in the Alcator C-Mod Tokamak
journal, December 2016

  • Liu, Z. X.; Xu, X. Q.; Gao, X.
  • Physics of Plasmas, Vol. 23, Issue 12
  • DOI: 10.1063/1.4972088

Dependence of the L-Mode scrape-off layer power fall-off length on the upper triangularity in TCV
journal, March 2018

  • Faitsch, M.; Maurizio, R.; Gallo, A.
  • Plasma Physics and Controlled Fusion, Vol. 60, Issue 4
  • DOI: 10.1088/1361-6587/aaaef7

Supersonic helium beam diagnostic for fluctuation measurements of electron temperature and density at the Tokamak TEXTOR
journal, June 2012

  • Kruezi, U.; Stoschus, H.; Schweer, B.
  • Review of Scientific Instruments, Vol. 83, Issue 6
  • DOI: 10.1063/1.4707150

Real time capable infrared thermography for ASDEX Upgrade
journal, November 2015

  • Sieglin, B.; Faitsch, M.; Herrmann, A.
  • Review of Scientific Instruments, Vol. 86, Issue 11
  • DOI: 10.1063/1.4935580

I-mode: an H-mode energy confinement regime with L-mode particle transport in Alcator C-Mod
journal, August 2010


Turbulence intermittency linked to the weakly coherent mode in ASDEX Upgrade I-mode plasmas
journal, May 2016


H-mode power threshold and transition in ASDEX Upgrade
journal, May 1998


Inter-ELM Power Decay Length for JET and ASDEX Upgrade: Measurement and Comparison with Heuristic Drift-Based Model
journal, November 2011


Fluctuating zonal flows in the I-mode regime in Alcator C-Mod
journal, May 2013

  • Cziegler, I.; Diamond, P. H.; Fedorczak, N.
  • Physics of Plasmas, Vol. 20, Issue 5
  • DOI: 10.1063/1.4803914

Theoretical explanation of I-mode impurity removal and energy confinement
journal, July 2018

  • Espinosa, Silvia; Catto, Peter J.
  • Plasma Physics and Controlled Fusion, Vol. 60, Issue 9
  • DOI: 10.1088/1361-6587/aad0c9

Physics and performance of the I-mode regime over an expanded operating space on Alcator C-Mod
journal, October 2017


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
  • DOI: 10.1088/1361-6587/aa97e8

Electron temperature fluctuations associated with the weakly coherent mode in the edge of I-mode plasmas
journal, October 2011


Investigation of scrape-off layer and divertor heat transport in ASDEX Upgrade L-mode
journal, April 2016


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


ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets
journal, November 2015


Study of near scrape-off layer (SOL) temperature and density gradient lengths with Thomson scattering
journal, November 2015


Heat-flux footprints for I-mode and EDA H-mode plasmas on Alcator C-Mod
journal, July 2013


ADX: a high field, high power density, advanced divertor and RF tokamak
journal, April 2015


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


Chapter 1: Overview and summary
journal, December 1999

  • Editors, ITER Physics Basis; Co-Chairs, ITER Physics Expert Group Chairs an; Unit, ITER Joint Central Team and Physics
  • Nuclear Fusion, Vol. 39, Issue 12
  • DOI: 10.1088/0029-5515/39/12/301

Measurement of turbulent electron temperature fluctuations on the ASDEX Upgrade tokamak using correlated electron cyclotron emission
journal, July 2016

  • Freethy, S. J.; Conway, G. D.; Classen, I.
  • Review of Scientific Instruments, Vol. 87, Issue 11
  • DOI: 10.1063/1.4958908

Chapter 2: Plasma confinement and transport
journal, December 1999

  • Transport, ITER Physics Expert Group on Confin; Database, ITER Physics Expert Group on Confin; Editors, ITER Physics Basis
  • Nuclear Fusion, Vol. 39, Issue 12
  • DOI: 10.1088/0029-5515/39/12/302

Turbulence characteristics of the I-mode confinement regime in ASDEX Upgrade
journal, July 2017


Core impurity transport in Alcator C-Mod L-, I- and H-mode plasmas
journal, February 2015


Study of near SOL decay lengths in ASDEX Upgrade under attached and detached divertor conditions
journal, August 2017

  • Sun, H. J.; Wolfrum, E.; Kurzan, B.
  • Plasma Physics and Controlled Fusion, Vol. 59, Issue 10
  • DOI: 10.1088/1361-6587/aa7777

Characterization of density fluctuations during the search for an I-mode regime on the DIII-D tokamak
journal, August 2015


Edge-localized mode avoidance and pedestal structure in I-mode plasmas
journal, May 2014

  • Walk, J. R.; Hughes, J. W.; Hubbard, A. E.
  • Physics of Plasmas, Vol. 21, Issue 5
  • DOI: 10.1063/1.4872220

Edge energy transport barrier and turbulence in the I-mode regime on Alcator C-Mod
journal, May 2011

  • Hubbard, A. E.; Whyte, D. G.; Churchill, R. M.
  • Physics of Plasmas, Vol. 18, Issue 5
  • DOI: 10.1063/1.3582135

Magnetic field pitch angle and perpendicular velocity measurements from multi-point time-delay estimation of poloidal correlation reflectometry
journal, January 2017


Helium line ratio spectroscopy for high spatiotemporal resolution plasma edge profile measurements at ASDEX Upgrade (invited)
journal, October 2018

  • Griener, M.; Wolfrum, E.; Cavedon, M.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5034446

The I-mode confinement regime at ASDEX Upgrade: global properties and characterization of strongly intermittent density fluctuations
journal, October 2016


Edge and core Thomson scattering systems and their calibration on the ASDEX Upgrade tokamak
journal, October 2011

  • Kurzan, B.; Murmann, H. D.
  • Review of Scientific Instruments, Vol. 82, Issue 10
  • DOI: 10.1063/1.3643771

Application of AXUV diode detectors at ASDEX Upgrade
journal, March 2014

  • Bernert, M.; Eich, T.; Burckhart, A.
  • Review of Scientific Instruments, Vol. 85, Issue 3
  • DOI: 10.1063/1.4867662

Geodesic oscillations and the weakly coherent mode in the I-mode of ASDEX Upgrade
journal, June 2015


Multi-device studies of pedestal physics and confinement in the I-mode regime
journal, July 2016


I-mode studies at ASDEX Upgrade: L-I and I-H transitions, pedestal and confinement properties
journal, October 2016


Integrated Data Analysis of Profile Diagnostics at ASDEX Upgrade
journal, October 2010

  • Fischer, R.; Fuchs, C. J.; Kurzan, B.
  • Fusion Science and Technology, Vol. 58, Issue 2
  • DOI: 10.13182/FST10-110