High confinement hybrid scenario in JET and its significance for ITER

E. Joffrin, J. Hobirk, M. Beurskens, M. Brix, P. Buratti, C. Challis, F. Crisanti, C. Giroud, F. Imbeaux, D.C. McDonald, P. Maget, P. Mantica, F. Rimini, A.C.C. Sips, Tuomas Tala, I. Voitsekovitch, J. Citrin, J. García, I. Jenkins, J. LonnrothL. Frassinetti, M. Piovesan, G. Sergienko, JET-EFDA collaborators

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Abstract

In the last campaigns, JET has extended the hybrid scenario with q profile close to unity in the plasma core to higher confinement (H98y2 up to 1.4-1.5) for both high and low triangularity. This has been achieved by creating a large region of weak magnetic in the plasma core. With these performances, 50% of the total current is generated non-inductively would produce in ITER a discharge of 1000s duration. The effect of this broad q profiles shape could reduce transport in the core in particular in the low shape scenario which also has the strongest rotation gradients. With broad q profile neoclassical tearing mode stability is shown to be improved. The pedestal does not seem to depend crucially on the modification of the magnetic shear, but shows a constant improvement with power and β. This improvement is more pronounced at low shape than low shape. High shapes can also be affected by high recycling flux that can impact on the pedestal confinement. Given the inapplicability of existing confinement scaling law at βN higher than 2, the extrapolation of these scenarios to ITER is using instead a dimensionless approach. There is good prospect to produce in ITER long pulse operation with Q approaching 10 but there are large uncertainties in particular with respect to the role of rotation on transport.
Original languageEnglish
Title of host publicationProceedings of the 23rd IAEA Fusion Energy Conference
PublisherInternational Atomic Energy Agency IAEA
Publication statusPublished - 2010
MoE publication typeNot Eligible
Event23rd IAEA Fusion Energy Conference, FEC 2010 - Daejon, Korea, Republic of
Duration: 10 Oct 201016 Oct 2010

Conference

Conference23rd IAEA Fusion Energy Conference, FEC 2010
CountryKorea, Republic of
CityDaejon
Period10/10/1016/10/10

Fingerprint

profiles
recycling
scaling laws
extrapolation
unity
shear
gradients
pulses

Keywords

  • plasma physics
  • fusion energy

Cite this

Joffrin, E., Hobirk, J., Beurskens, M., Brix, M., Buratti, P., Challis, C., ... JET-EFDA collaborators (2010). High confinement hybrid scenario in JET and its significance for ITER. In Proceedings of the 23rd IAEA Fusion Energy Conference [EXC/1-1] International Atomic Energy Agency IAEA.
Joffrin, E. ; Hobirk, J. ; Beurskens, M. ; Brix, M. ; Buratti, P. ; Challis, C. ; Crisanti, F. ; Giroud, C. ; Imbeaux, F. ; McDonald, D.C. ; Maget, P. ; Mantica, P. ; Rimini, F. ; Sips, A.C.C. ; Tala, Tuomas ; Voitsekovitch, I. ; Citrin, J. ; García, J. ; Jenkins, I. ; Lonnroth, J. ; Frassinetti, L. ; Piovesan, M. ; Sergienko, G. ; JET-EFDA collaborators. / High confinement hybrid scenario in JET and its significance for ITER. Proceedings of the 23rd IAEA Fusion Energy Conference. International Atomic Energy Agency IAEA, 2010.
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abstract = "In the last campaigns, JET has extended the hybrid scenario with q profile close to unity in the plasma core to higher confinement (H98y2 up to 1.4-1.5) for both high and low triangularity. This has been achieved by creating a large region of weak magnetic in the plasma core. With these performances, 50{\%} of the total current is generated non-inductively would produce in ITER a discharge of 1000s duration. The effect of this broad q profiles shape could reduce transport in the core in particular in the low shape scenario which also has the strongest rotation gradients. With broad q profile neoclassical tearing mode stability is shown to be improved. The pedestal does not seem to depend crucially on the modification of the magnetic shear, but shows a constant improvement with power and β. This improvement is more pronounced at low shape than low shape. High shapes can also be affected by high recycling flux that can impact on the pedestal confinement. Given the inapplicability of existing confinement scaling law at βN higher than 2, the extrapolation of these scenarios to ITER is using instead a dimensionless approach. There is good prospect to produce in ITER long pulse operation with Q approaching 10 but there are large uncertainties in particular with respect to the role of rotation on transport.",
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author = "E. Joffrin and J. Hobirk and M. Beurskens and M. Brix and P. Buratti and C. Challis and F. Crisanti and C. Giroud and F. Imbeaux and D.C. McDonald and P. Maget and P. Mantica and F. Rimini and A.C.C. Sips and Tuomas Tala and I. Voitsekovitch and J. Citrin and J. Garc{\'i}a and I. Jenkins and J. Lonnroth and L. Frassinetti and M. Piovesan and G. Sergienko and {JET-EFDA collaborators}",
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Joffrin, E, Hobirk, J, Beurskens, M, Brix, M, Buratti, P, Challis, C, Crisanti, F, Giroud, C, Imbeaux, F, McDonald, DC, Maget, P, Mantica, P, Rimini, F, Sips, ACC, Tala, T, Voitsekovitch, I, Citrin, J, García, J, Jenkins, I, Lonnroth, J, Frassinetti, L, Piovesan, M, Sergienko, G & JET-EFDA collaborators 2010, High confinement hybrid scenario in JET and its significance for ITER. in Proceedings of the 23rd IAEA Fusion Energy Conference., EXC/1-1, International Atomic Energy Agency IAEA, 23rd IAEA Fusion Energy Conference, FEC 2010, Daejon, Korea, Republic of, 10/10/10.

High confinement hybrid scenario in JET and its significance for ITER. / Joffrin, E.; Hobirk, J.; Beurskens, M.; Brix, M.; Buratti, P.; Challis, C.; Crisanti, F.; Giroud, C.; Imbeaux, F.; McDonald, D.C.; Maget, P.; Mantica, P.; Rimini, F.; Sips, A.C.C.; Tala, Tuomas; Voitsekovitch, I.; Citrin, J.; García, J.; Jenkins, I.; Lonnroth, J.; Frassinetti, L.; Piovesan, M.; Sergienko, G.; JET-EFDA collaborators.

Proceedings of the 23rd IAEA Fusion Energy Conference. International Atomic Energy Agency IAEA, 2010. EXC/1-1.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - High confinement hybrid scenario in JET and its significance for ITER

AU - Joffrin, E.

AU - Hobirk, J.

AU - Beurskens, M.

AU - Brix, M.

AU - Buratti, P.

AU - Challis, C.

AU - Crisanti, F.

AU - Giroud, C.

AU - Imbeaux, F.

AU - McDonald, D.C.

AU - Maget, P.

AU - Mantica, P.

AU - Rimini, F.

AU - Sips, A.C.C.

AU - Tala, Tuomas

AU - Voitsekovitch, I.

AU - Citrin, J.

AU - García, J.

AU - Jenkins, I.

AU - Lonnroth, J.

AU - Frassinetti, L.

AU - Piovesan, M.

AU - Sergienko, G.

AU - JET-EFDA collaborators

PY - 2010

Y1 - 2010

N2 - In the last campaigns, JET has extended the hybrid scenario with q profile close to unity in the plasma core to higher confinement (H98y2 up to 1.4-1.5) for both high and low triangularity. This has been achieved by creating a large region of weak magnetic in the plasma core. With these performances, 50% of the total current is generated non-inductively would produce in ITER a discharge of 1000s duration. The effect of this broad q profiles shape could reduce transport in the core in particular in the low shape scenario which also has the strongest rotation gradients. With broad q profile neoclassical tearing mode stability is shown to be improved. The pedestal does not seem to depend crucially on the modification of the magnetic shear, but shows a constant improvement with power and β. This improvement is more pronounced at low shape than low shape. High shapes can also be affected by high recycling flux that can impact on the pedestal confinement. Given the inapplicability of existing confinement scaling law at βN higher than 2, the extrapolation of these scenarios to ITER is using instead a dimensionless approach. There is good prospect to produce in ITER long pulse operation with Q approaching 10 but there are large uncertainties in particular with respect to the role of rotation on transport.

AB - In the last campaigns, JET has extended the hybrid scenario with q profile close to unity in the plasma core to higher confinement (H98y2 up to 1.4-1.5) for both high and low triangularity. This has been achieved by creating a large region of weak magnetic in the plasma core. With these performances, 50% of the total current is generated non-inductively would produce in ITER a discharge of 1000s duration. The effect of this broad q profiles shape could reduce transport in the core in particular in the low shape scenario which also has the strongest rotation gradients. With broad q profile neoclassical tearing mode stability is shown to be improved. The pedestal does not seem to depend crucially on the modification of the magnetic shear, but shows a constant improvement with power and β. This improvement is more pronounced at low shape than low shape. High shapes can also be affected by high recycling flux that can impact on the pedestal confinement. Given the inapplicability of existing confinement scaling law at βN higher than 2, the extrapolation of these scenarios to ITER is using instead a dimensionless approach. There is good prospect to produce in ITER long pulse operation with Q approaching 10 but there are large uncertainties in particular with respect to the role of rotation on transport.

KW - plasma physics

KW - fusion energy

UR - http://www-pub.iaea.org/mtcd/meetings/PDFplus/2010/cn180/cn180_BookOfAbstracts.pdf

M3 - Conference article in proceedings

BT - Proceedings of the 23rd IAEA Fusion Energy Conference

PB - International Atomic Energy Agency IAEA

ER -

Joffrin E, Hobirk J, Beurskens M, Brix M, Buratti P, Challis C et al. High confinement hybrid scenario in JET and its significance for ITER. In Proceedings of the 23rd IAEA Fusion Energy Conference. International Atomic Energy Agency IAEA. 2010. EXC/1-1