Yves MartinYves Martin

Centre de Recherches en Physique des PlasmasAssociation Euratom - Confédération Suisse

Ecole Polytechnique Fédérale de Lausanne (EPFL)CH - 1015 Lausanne, Switzerland

ITPA – CDBMITPA – CDBMH-mode threshold databaseH-mode threshold database

Threshold Threshold database statusdatabase status

May 2007May 2007 - - LausanneLausanne

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 2

Action list decided in Chengdu, October 2006Action list decided in Chengdu, October 2006

New data• JFT-2M TT 30.11.06• CHS TT 30.11.06• NSTX SK 30.11.06• MAST MV 30.11.06• New version of DB (4v7) YM 31.12.06

Recommended scaling• Confirm data selection (individually /tokamaks) ALL 30.11• Insert corrections / ‘1st estimation’ YM 31.12• Estimate fit parameters ALL 31.1• Discussion / release ALL next meeting

Other Work• Analysis, papers, ...

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 3

Action status – New dataAction status – New data

No new data sent

Action ?• Continue waiting• Stop waiting

Waiting: • JFT-2M TT 30.06.07 ?• CHS TT 30.06.07 ?• NSTX SK 30.06.07 ?• MAST MV 30.06.07 ?

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 4

Action status – recommended scalingAction status – recommended scaling

New version of the database released on 30.6.2006• IGDBTH4v6• Contains new data selection parameters, were agreed

Data selection• Different selection criteria: seldb1, 2, IAEA02, ..., EFPW05_red• Some errors in AUG selection

12 removed (Too early) 10 added

• One error in CMOD data Density in one discharge

• A new version of the DB: IGDBTH4v6b

Comments on fits• F.Ryter agreed

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 5

Recommended scalingRecommended scaling

Large data set:

Reduced data set:

With changes in selected set: • n: 0.74 => 0.75; B: 074 => 0.73; R: 1.06 => 1.07• RMS: 29.5% => 29.4;• ITER: Pth(n=1.0): 92 => 93 MW;

Pthresh 1.97 ne0.74

B0.74 a

0.96 R1.06=

Pthresh 3.44 ne0.47

B0.65 a

1.37 R0.26=

ITER: Pth(n=0.5) = 31 [28-33] MW

Pth(n=1.0) = 42 [38-47] MW

ITER: Pth(n=0.5) = 55 [49-61] MW

Pth(n=1.0) = 92 [79-107] MW

Pthresh 1.97 ne0.74

B0.74 a

0.96 R1.06=

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 6

Action status - analysisAction status - analysis

Hysteresis• Variation of ne and Bt dependence with tokamak size

Scaling• Refine scaling

Access to 'good' confinement regime• Minimum threshold power for type I ELMs• Minimum threshold power for good confinement regime

Density at the minimum threshold power

Influence of power fraction to electrons

0D modelling of discharge evolution

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 7

Action status – Issue CardAction status – Issue Card

Enough additional power during pulse evolution

Isotope identity pulses

List of parameters / actions to reduce the threshold power during ITER pulse evolution

What should we do for these ICs ?

Yves Martin, ITPA TG CDBM LH Transitions, May 2007, Lausanne 8

TalksTalks

Recent H-mode threshold results on Alcator C-Mod, J. Snipes

Relation between confinement and distance to LH power threshold in ASDEX Upgrade, F. Ryter

DIII-D H-mode threshold and ITER issue implications, J. DeBoo

Data analysis, ITER Issue Card, actions plans, presentations, publications, Y. Martin