Characterization of the I-phase regime at TCV

the TCV Team and the EUROfusion Tokamak Exploitation Team

doi:10.1088/1741-4326/ad96cb

Characterization of the I-phase regime at TCV

the TCV Team and the EUROfusion Tokamak Exploitation Team

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

The I-phase is an H-mode confinement regime of tokamaks characterized by limit cycle oscillations, the so-called LCOs or bursts. These bursts are the manifestation of a periodic flattening of the plasma edge pressure profile. The profile flattening is caused by increased radial transport, driven by a high-frequency plasma edge mode that periodically appears. This short-living mode is intrinsically connected to each burst. It vanishes once the profiles are fully flattened, and it reestablishes during profile recovery once critical gradients are reached and a new cycle begins. In this paper, we describe for the first time the unambiguous presence of the I-phase at the tokamak `a configuration variable (TCV). As the I-phase confinement regime is found in the parameter regime between the L-mode and the fully developed H-mode, it is often confused with dithers between H-mode and L-mode. Therefore, we are highlighting the differences between these two phenomena. Furthermore, we show the two-dimensional dynamics of the I-phase mode and bursts and the associated filamentary transport, enabled by the outstanding capabilities of the 2D TCV Gas Puff Imaging diagnostics.

Original language	English
Article number	016041
Journal	Nuclear Fusion
Volume	65
Issue number	1
DOIs	https://doi.org/10.1088/1741-4326/ad96cb
State	Published - Jan 1 2025

Funding

This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 — EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them. This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 - EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them.

Keywords

I-phase
LCO
TCV
fusion
gas puff imaging
limit cycle oscillations
plasma modes

Access to Document

10.1088/1741-4326/ad96cb

Cite this

@article{c2aa35a480c64d6392b42092f2753a51,

title = "Characterization of the I-phase regime at TCV",

abstract = "The I-phase is an H-mode confinement regime of tokamaks characterized by limit cycle oscillations, the so-called LCOs or bursts. These bursts are the manifestation of a periodic flattening of the plasma edge pressure profile. The profile flattening is caused by increased radial transport, driven by a high-frequency plasma edge mode that periodically appears. This short-living mode is intrinsically connected to each burst. It vanishes once the profiles are fully flattened, and it reestablishes during profile recovery once critical gradients are reached and a new cycle begins. In this paper, we describe for the first time the unambiguous presence of the I-phase at the tokamak `a configuration variable (TCV). As the I-phase confinement regime is found in the parameter regime between the L-mode and the fully developed H-mode, it is often confused with dithers between H-mode and L-mode. Therefore, we are highlighting the differences between these two phenomena. Furthermore, we show the two-dimensional dynamics of the I-phase mode and bursts and the associated filamentary transport, enabled by the outstanding capabilities of the 2D TCV Gas Puff Imaging diagnostics.",

keywords = "I-phase, LCO, TCV, fusion, gas puff imaging, limit cycle oscillations, plasma modes",

author = "\{the TCV Team and the EUROfusion Tokamak Exploitation Team\} and M. Griener and C. W{\"u}thrich and Y. Wang and D. Brida and M. Faitsch and N. Offeddu and C. Theiler and H. Reimerdes and M. Agostini and E. Alessi and S. Alberti and Y. Andrebe and H. Arnichand and J. Balbin and F. Bagnato and M. Baquero-Ruiz and M. Bernert and W. Bin and P. Blanchard and Blanken, \{T. C.\} and Boedo, \{J. A.\} and S. Brunner and C. Bogar and O. Bogar and T. Bolzonella and F. Bombarda and F. Bouquey and C. Bowman and D. Brunetti and J. Buermans and H. Bufferand and L. Calacci and Y. Camenen and S. Carli and D. Carnevale and F. Carpanese and F. Causa and J. Cavalier and M. Cavedon and Cazabonne, \{J. A.\} and J. Cerovsky and R. Chandra and Jayalekshmi, \{A. Chandrarajan\} and O. Chella{\"i} and P. Chmielewski and D. Choi and G. Ciraolo and Classen, \{I. G.J.\} and S. Gorno and W. Tierens",

note = "Publisher Copyright: {\textcopyright} 2024 The Author(s).",

year = "2025",

month = jan,

day = "1",

doi = "10.1088/1741-4326/ad96cb",

language = "English",

volume = "65",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing",

number = "1",

}

TY - JOUR

T1 - Characterization of the I-phase regime at TCV

AU - the TCV Team and the EUROfusion Tokamak Exploitation Team

AU - Griener, M.

AU - Wüthrich, C.

AU - Wang, Y.

AU - Brida, D.

AU - Faitsch, M.

AU - Offeddu, N.

AU - Theiler, C.

AU - Reimerdes, H.

AU - Agostini, M.

AU - Alessi, E.

AU - Alberti, S.

AU - Andrebe, Y.

AU - Arnichand, H.

AU - Balbin, J.

AU - Bagnato, F.

AU - Baquero-Ruiz, M.

AU - Bernert, M.

AU - Bin, W.

AU - Blanchard, P.

AU - Blanken, T. C.

AU - Boedo, J. A.

AU - Brunner, S.

AU - Bogar, C.

AU - Bogar, O.

AU - Bolzonella, T.

AU - Bombarda, F.

AU - Bouquey, F.

AU - Bowman, C.

AU - Brunetti, D.

AU - Buermans, J.

AU - Bufferand, H.

AU - Calacci, L.

AU - Camenen, Y.

AU - Carli, S.

AU - Carnevale, D.

AU - Carpanese, F.

AU - Causa, F.

AU - Cavalier, J.

AU - Cavedon, M.

AU - Cazabonne, J. A.

AU - Cerovsky, J.

AU - Chandra, R.

AU - Jayalekshmi, A. Chandrarajan

AU - Chellaï, O.

AU - Chmielewski, P.

AU - Choi, D.

AU - Ciraolo, G.

AU - Classen, I. G.J.

AU - Gorno, S.

AU - Tierens, W.

PY - 2025/1/1

Y1 - 2025/1/1

N2 - The I-phase is an H-mode confinement regime of tokamaks characterized by limit cycle oscillations, the so-called LCOs or bursts. These bursts are the manifestation of a periodic flattening of the plasma edge pressure profile. The profile flattening is caused by increased radial transport, driven by a high-frequency plasma edge mode that periodically appears. This short-living mode is intrinsically connected to each burst. It vanishes once the profiles are fully flattened, and it reestablishes during profile recovery once critical gradients are reached and a new cycle begins. In this paper, we describe for the first time the unambiguous presence of the I-phase at the tokamak `a configuration variable (TCV). As the I-phase confinement regime is found in the parameter regime between the L-mode and the fully developed H-mode, it is often confused with dithers between H-mode and L-mode. Therefore, we are highlighting the differences between these two phenomena. Furthermore, we show the two-dimensional dynamics of the I-phase mode and bursts and the associated filamentary transport, enabled by the outstanding capabilities of the 2D TCV Gas Puff Imaging diagnostics.

AB - The I-phase is an H-mode confinement regime of tokamaks characterized by limit cycle oscillations, the so-called LCOs or bursts. These bursts are the manifestation of a periodic flattening of the plasma edge pressure profile. The profile flattening is caused by increased radial transport, driven by a high-frequency plasma edge mode that periodically appears. This short-living mode is intrinsically connected to each burst. It vanishes once the profiles are fully flattened, and it reestablishes during profile recovery once critical gradients are reached and a new cycle begins. In this paper, we describe for the first time the unambiguous presence of the I-phase at the tokamak `a configuration variable (TCV). As the I-phase confinement regime is found in the parameter regime between the L-mode and the fully developed H-mode, it is often confused with dithers between H-mode and L-mode. Therefore, we are highlighting the differences between these two phenomena. Furthermore, we show the two-dimensional dynamics of the I-phase mode and bursts and the associated filamentary transport, enabled by the outstanding capabilities of the 2D TCV Gas Puff Imaging diagnostics.

KW - I-phase

KW - LCO

KW - TCV

KW - fusion

KW - gas puff imaging

KW - limit cycle oscillations

KW - plasma modes

UR - https://www.scopus.com/pages/publications/86000336051

U2 - 10.1088/1741-4326/ad96cb

DO - 10.1088/1741-4326/ad96cb

M3 - Article

AN - SCOPUS:86000336051

SN - 0029-5515

VL - 65

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 1

M1 - 016041

ER -

Characterization of the I-phase regime at TCV

Abstract

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this