Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D

Tuomas Tala, F. Imbeaux, V.V. Parail, C. Bourdelle, G. Corrigan, X. Garbet, D. Heading, X. Litaudon, P.I. Strand, J. Weiland, JET-EFDA Contributors

Research output: Contribution to journalArticleScientificpeer-review

40 Citations (Scopus)

Abstract

For the first time, the predictive capabilities of the mixed Bohm/GyroBohm, Weiland and 'retuned' GLF23 transport models are investigated with ITB discharges from the ITPA ITB database with fully predictive, time-dependent transport simulations. A range of plasma conditions is examined for JET, JT-60U and DIII-D discharges with internal transport barriers (ITBs). The simulations show that the Bohm/GyroBohm model is able to follow the time evolution of the discharge from the preheating phase without an ITB through the ITB onset phase until the high performance phase with fair accuracy in most cases in JET and JT-60U. This indicates the importance of the interplay between the magnetic shear and ωE×B flow shear in ITB formation since these are the mechanisms that govern the ITB physics in the model. In order to achieve good agreement in DIII-D, the α-stabilization had to be included in the model, emphasizing the role played by the α-stabilization in the physics of the ITBs. The Weiland and GLF23 transport models show limited agreement between the model predictions and experimental time evolution of the ITB and kinetic plasma profiles. The Weiland model does not form a clear ITB in any of the three tokamaks despite varying plasma profiles, such as the q-profile. On the other hand, the average temperatures and density are often in fair agreement with experimental values. The GLF23 model often predicts an ITB, but its radial location is often too far inside the plasma, or shrinks as the simulations proceed in time. Consequently, the central temperatures at the end of the simulations during the high performance phase are usually underestimated. It is worth noting that GLF23 features in general better predictions of the Te and Ti profiles outside the ITB than the other models studied. Achieving the quantitative capability to predict the multi-channel ITB dynamics with fully predictive, time-dependent transport simulations has turned out to be extremely challenging.
Original languageEnglish
Pages (from-to)548-561
Number of pages14
JournalNuclear Fusion
Volume46
Issue number5
DOIs
Publication statusPublished - 2006
MoE publication typeA1 Journal article-refereed

Fingerprint

simulation
profiles
shear flow
stabilization
physics
predictions
heating
temperature
kinetics

Keywords

  • JET
  • plasma
  • fusion energy
  • fusion reactors
  • ITER
  • internal transport barriers

Cite this

Tala, T., Imbeaux, F., Parail, V. V., Bourdelle, C., Corrigan, G., Garbet, X., ... JET-EFDA Contributors (2006). Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D. Nuclear Fusion, 46(5), 548-561. https://doi.org/10.1088/0029-5515/46/5/007
Tala, Tuomas ; Imbeaux, F. ; Parail, V.V. ; Bourdelle, C. ; Corrigan, G. ; Garbet, X. ; Heading, D. ; Litaudon, X. ; Strand, P.I. ; Weiland, J. ; JET-EFDA Contributors. / Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D. In: Nuclear Fusion. 2006 ; Vol. 46, No. 5. pp. 548-561.
@article{b407d3f8a7a243ae8ec39dc3364c5678,
title = "Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D",
abstract = "For the first time, the predictive capabilities of the mixed Bohm/GyroBohm, Weiland and 'retuned' GLF23 transport models are investigated with ITB discharges from the ITPA ITB database with fully predictive, time-dependent transport simulations. A range of plasma conditions is examined for JET, JT-60U and DIII-D discharges with internal transport barriers (ITBs). The simulations show that the Bohm/GyroBohm model is able to follow the time evolution of the discharge from the preheating phase without an ITB through the ITB onset phase until the high performance phase with fair accuracy in most cases in JET and JT-60U. This indicates the importance of the interplay between the magnetic shear and ωE×B flow shear in ITB formation since these are the mechanisms that govern the ITB physics in the model. In order to achieve good agreement in DIII-D, the α-stabilization had to be included in the model, emphasizing the role played by the α-stabilization in the physics of the ITBs. The Weiland and GLF23 transport models show limited agreement between the model predictions and experimental time evolution of the ITB and kinetic plasma profiles. The Weiland model does not form a clear ITB in any of the three tokamaks despite varying plasma profiles, such as the q-profile. On the other hand, the average temperatures and density are often in fair agreement with experimental values. The GLF23 model often predicts an ITB, but its radial location is often too far inside the plasma, or shrinks as the simulations proceed in time. Consequently, the central temperatures at the end of the simulations during the high performance phase are usually underestimated. It is worth noting that GLF23 features in general better predictions of the Te and Ti profiles outside the ITB than the other models studied. Achieving the quantitative capability to predict the multi-channel ITB dynamics with fully predictive, time-dependent transport simulations has turned out to be extremely challenging.",
keywords = "JET, plasma, fusion energy, fusion reactors, ITER, internal transport barriers",
author = "Tuomas Tala and F. Imbeaux and V.V. Parail and C. Bourdelle and G. Corrigan and X. Garbet and D. Heading and X. Litaudon and P.I. Strand and J. Weiland and {JET-EFDA Contributors}",
year = "2006",
doi = "10.1088/0029-5515/46/5/007",
language = "English",
volume = "46",
pages = "548--561",
journal = "Nuclear Fusion",
issn = "0029-5515",
publisher = "Institute of Physics IOP",
number = "5",

}

Tala, T, Imbeaux, F, Parail, VV, Bourdelle, C, Corrigan, G, Garbet, X, Heading, D, Litaudon, X, Strand, PI, Weiland, J & JET-EFDA Contributors 2006, 'Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D', Nuclear Fusion, vol. 46, no. 5, pp. 548-561. https://doi.org/10.1088/0029-5515/46/5/007

Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D. / Tala, Tuomas; Imbeaux, F.; Parail, V.V.; Bourdelle, C.; Corrigan, G.; Garbet, X.; Heading, D.; Litaudon, X.; Strand, P.I.; Weiland, J.; JET-EFDA Contributors.

In: Nuclear Fusion, Vol. 46, No. 5, 2006, p. 548-561.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Fully predictive time-dependent transport simulations of ITB plasmas in JET, JT-60U and DIII-D

AU - Tala, Tuomas

AU - Imbeaux, F.

AU - Parail, V.V.

AU - Bourdelle, C.

AU - Corrigan, G.

AU - Garbet, X.

AU - Heading, D.

AU - Litaudon, X.

AU - Strand, P.I.

AU - Weiland, J.

AU - JET-EFDA Contributors,

PY - 2006

Y1 - 2006

N2 - For the first time, the predictive capabilities of the mixed Bohm/GyroBohm, Weiland and 'retuned' GLF23 transport models are investigated with ITB discharges from the ITPA ITB database with fully predictive, time-dependent transport simulations. A range of plasma conditions is examined for JET, JT-60U and DIII-D discharges with internal transport barriers (ITBs). The simulations show that the Bohm/GyroBohm model is able to follow the time evolution of the discharge from the preheating phase without an ITB through the ITB onset phase until the high performance phase with fair accuracy in most cases in JET and JT-60U. This indicates the importance of the interplay between the magnetic shear and ωE×B flow shear in ITB formation since these are the mechanisms that govern the ITB physics in the model. In order to achieve good agreement in DIII-D, the α-stabilization had to be included in the model, emphasizing the role played by the α-stabilization in the physics of the ITBs. The Weiland and GLF23 transport models show limited agreement between the model predictions and experimental time evolution of the ITB and kinetic plasma profiles. The Weiland model does not form a clear ITB in any of the three tokamaks despite varying plasma profiles, such as the q-profile. On the other hand, the average temperatures and density are often in fair agreement with experimental values. The GLF23 model often predicts an ITB, but its radial location is often too far inside the plasma, or shrinks as the simulations proceed in time. Consequently, the central temperatures at the end of the simulations during the high performance phase are usually underestimated. It is worth noting that GLF23 features in general better predictions of the Te and Ti profiles outside the ITB than the other models studied. Achieving the quantitative capability to predict the multi-channel ITB dynamics with fully predictive, time-dependent transport simulations has turned out to be extremely challenging.

AB - For the first time, the predictive capabilities of the mixed Bohm/GyroBohm, Weiland and 'retuned' GLF23 transport models are investigated with ITB discharges from the ITPA ITB database with fully predictive, time-dependent transport simulations. A range of plasma conditions is examined for JET, JT-60U and DIII-D discharges with internal transport barriers (ITBs). The simulations show that the Bohm/GyroBohm model is able to follow the time evolution of the discharge from the preheating phase without an ITB through the ITB onset phase until the high performance phase with fair accuracy in most cases in JET and JT-60U. This indicates the importance of the interplay between the magnetic shear and ωE×B flow shear in ITB formation since these are the mechanisms that govern the ITB physics in the model. In order to achieve good agreement in DIII-D, the α-stabilization had to be included in the model, emphasizing the role played by the α-stabilization in the physics of the ITBs. The Weiland and GLF23 transport models show limited agreement between the model predictions and experimental time evolution of the ITB and kinetic plasma profiles. The Weiland model does not form a clear ITB in any of the three tokamaks despite varying plasma profiles, such as the q-profile. On the other hand, the average temperatures and density are often in fair agreement with experimental values. The GLF23 model often predicts an ITB, but its radial location is often too far inside the plasma, or shrinks as the simulations proceed in time. Consequently, the central temperatures at the end of the simulations during the high performance phase are usually underestimated. It is worth noting that GLF23 features in general better predictions of the Te and Ti profiles outside the ITB than the other models studied. Achieving the quantitative capability to predict the multi-channel ITB dynamics with fully predictive, time-dependent transport simulations has turned out to be extremely challenging.

KW - JET

KW - plasma

KW - fusion energy

KW - fusion reactors

KW - ITER

KW - internal transport barriers

U2 - 10.1088/0029-5515/46/5/007

DO - 10.1088/0029-5515/46/5/007

M3 - Article

VL - 46

SP - 548

EP - 561

JO - Nuclear Fusion

JF - Nuclear Fusion

SN - 0029-5515

IS - 5

ER -