Core transport properties in JT-60U and JET identity plasmas

ITPA Transport & Confinement Topical Group, JT-60 Team, JET-EFDA collaborators

Research output: Contribution to journalArticleScientificpeer-review

9 Citations (Scopus)

Abstract

The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.

Original languageEnglish
Article number073020
Number of pages13
JournalNuclear Fusion
Volume51
Issue number7
DOIs
Publication statusPublished - 1 Jul 2011
MoE publication typeNot Eligible

Fingerprint

transport properties
profiles
shear
safety factors
Larmor radius
neutral beams
configurations
ripples
Mach number
ions
fusion
electron energy
current density
physics
collisions
radii
predictions
magnetic fields
electrons

Cite this

ITPA Transport & Confinement Topical Group, JT-60 Team, & JET-EFDA collaborators (2011). Core transport properties in JT-60U and JET identity plasmas. Nuclear Fusion, 51(7), [073020]. https://doi.org/10.1088/0029-5515/51/7/073020
ITPA Transport & Confinement Topical Group ; JT-60 Team ; JET-EFDA collaborators. / Core transport properties in JT-60U and JET identity plasmas. In: Nuclear Fusion. 2011 ; Vol. 51, No. 7.
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abstract = "The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.",
author = "X. Litaudon and Y. Sakamoto and {de Vries}, {P. C.} and Antti Salmi and Tuomas Tala and C. Angioni and S. Benkadda and M. Beurskens and C. Bourdelle and M. Brix and K. Cromb{\'e} and T. Fujita and S. Futatani and X Garbet and C. Giroud and Hawkes, {N. C.} and N. Hayashi and Hoang, {G. T.} and Hogeweij, {G. M.D.} and G. Matsunaga and T. Nakano and N. Oyama and V. Parail and K. Shinohara and T. Suzuki and M. Takechi and H. Takenaga and T. Takizuka and H. Urano and I. Voitsekhovitch and M. Yoshida and {ITPA Transport & Confinement Topical Group} and {JT-60 Team} and {JET-EFDA collaborators}",
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ITPA Transport & Confinement Topical Group, JT-60 Team & JET-EFDA collaborators 2011, 'Core transport properties in JT-60U and JET identity plasmas', Nuclear Fusion, vol. 51, no. 7, 073020. https://doi.org/10.1088/0029-5515/51/7/073020

Core transport properties in JT-60U and JET identity plasmas. / ITPA Transport & Confinement Topical Group; JT-60 Team; JET-EFDA collaborators.

In: Nuclear Fusion, Vol. 51, No. 7, 073020, 01.07.2011.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Core transport properties in JT-60U and JET identity plasmas

AU - Litaudon, X.

AU - Sakamoto, Y.

AU - de Vries, P. C.

AU - Salmi, Antti

AU - Tala, Tuomas

AU - Angioni, C.

AU - Benkadda, S.

AU - Beurskens, M.

AU - Bourdelle, C.

AU - Brix, M.

AU - Crombé, K.

AU - Fujita, T.

AU - Futatani, S.

AU - Garbet, X

AU - Giroud, C.

AU - Hawkes, N. C.

AU - Hayashi, N.

AU - Hoang, G. T.

AU - Hogeweij, G. M.D.

AU - Matsunaga, G.

AU - Nakano, T.

AU - Oyama, N.

AU - Parail, V.

AU - Shinohara, K.

AU - Suzuki, T.

AU - Takechi, M.

AU - Takenaga, H.

AU - Takizuka, T.

AU - Urano, H.

AU - Voitsekhovitch, I.

AU - Yoshida, M.

AU - ITPA Transport & Confinement Topical Group

AU - JT-60 Team

AU - JET-EFDA collaborators

PY - 2011/7/1

Y1 - 2011/7/1

N2 - The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.

AB - The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.

U2 - 10.1088/0029-5515/51/7/073020

DO - 10.1088/0029-5515/51/7/073020

M3 - Article

VL - 51

JO - Nuclear Fusion

JF - Nuclear Fusion

SN - 0029-5515

IS - 7

M1 - 073020

ER -

ITPA Transport & Confinement Topical Group, JT-60 Team, JET-EFDA collaborators. Core transport properties in JT-60U and JET identity plasmas. Nuclear Fusion. 2011 Jul 1;51(7). 073020. https://doi.org/10.1088/0029-5515/51/7/073020