Yves Martin

Centre de Recherches en Physique des PlasmasAssociation Euratom - Confédération SuisseEcole Polytechnique Fédérale de Lausanne

CH - 1015 Lausanne, Switzerland

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

IAEA - IAEA - NF paperNF paper

November 2004 - LisbonNovember 2004 - Lisbon

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 2

PlanPlan

Improvement between paper and poster• DB status

New data General data selection Data distribution

• Old scalings• Influence of the chosen divertors - best divertors• Influence of the chosen phases - remove 'bad' phases• Fits with equalised data representations

Random sub-selection Weights

• New parameter set - effect of the aspect ratio• Threshold power at low density• Prediction for ITER

Improvement still possible between poster and NF paper

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 3

DB statusDB status

New data• Table of new contributed data

New selection• Phase, shape, IgradB, ...

Data distribution

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U MAST NSTX PBXM TCV TUMAN-3M

200 400 600 Count

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U MAST NSTX PBXM TCV TUMAN-3M

0 0 0 0 37 6 0 0 18 6 89 22 82 0 10 5 46 0 24 0 49 3 27 35 10 0 1 0 0 0 6 1 1 2 0 0 53 0 0 2

226 66 91 0 172 0 0 0 12 0 6 0 35 0 0 0 0 0 36 0 22 0 0 0 0 0 0 0 4 0 16 0 1 0 0 0 5 0 0 0 0 0 0 0 5 0 0 0 0 20 0 0 1 0 16 14 0 0 0 0 0 0 0 15

43 232 184 18 58

555 53 58 20 6 5

51 15

314 94 247 22 465 9 75 72 1298

PHASE Count D DH LD LDL LH LHL OHMD OHMH

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 4

DB status IIDB status II

Data distribution

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U MAST NSTX PBXM TCV TUMAN-3M

0 0 43 0 0 0 0 0 232 0 0 0 0 184 0 0 0 18 0 0 0 0 58 0 0 0 0 0 491 64 0 0 53 0 0 0 0 58 0 0

15 0 5 0 0 0 0 6 0 0 5 0 0 0 0 0 0 0 50 1 0 15 0 0 0

43 232 184 18 58

555 53 58 20 6 5

51 15

20 15 241 957 65 1298

CONFIGURATION Count DN LIM SN SNB SNT

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U MAST NSTX PBXM TCV TUMAN-3M

0 43 0 232 0 184 0 18 0 58 0 555 0 53 0 58 15 5 0 6 5 0 0 51 0 0

43 232 184 18 58

555 53 58 20 6 5 51 0

20 1263 1283

IGRADB Count 0 1

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 5

DB status IIIDB status III

Data distribution

ne20

0

1

2

3

ASDEX AUG

CMOD COMPASS

D3D JET JFT2M JT60U

MAST NSTX

PBXM TCV

TUMAN-3M

|BT|

1 2

3 4

5 6

7 8

ASDEX AUG

CMOD COMPASS

D3D JET JFT2M JT60U

MAST NSTX

PBXM TCV

TUMAN-3M

TOK

R

1

2

3

ASDEX AUG

CMOD COMPASS

D3D JET JFT2M JT60U

MAST NSTX

PBXM TCV

TUMAN-3M

TOK

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9

2

ASDEX AUG

CMOD COMPASS

D3D JET JFT2M JT60U

MAST NSTX

PBXM TCV

TUMAN-3M

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 6

Previous scalingPrevious scaling

Jo Snipes - IAEA 2002

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U MAST NSTX PBXM TCV TUMAN-3M

200 400 600 Count

0.1 0.06

1 0.6 0.4 0.2

10 6 4 2 PL

.1 .07 1 .8 .6 .4 .3 .2 10 7 5 4 3 2

Pth1

0.4 0.7 0.9 1.2 1.4 1.7 1.9 2.2 2.4 2.7

ASDEX AUG

CMOD COMPASS

D3D JET JFT2M JT60U

MAST NSTX

PBXM TCV

TUMAN-3M

PL/Pth1

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 7

Scaling with full data setScaling with full data set

2002 Scaling:

Pth1 = 1.67 ne200.61 BT

0.78 a0.89 R0.94

RMSE = 25.1%

2004 scaling

Pth3 = 3.46 ne200.48 BT

0.65 a1.37 R0.26

RMSE = 32.4%

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 8

Select best divertor for each tokamak (where defined)

Effect of divertorEffect of divertor

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

MK0 MKIIGB MKSRP MkI MkIIa MkIIap

DIVERTOR NAME

PL/Pth1

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3

DIV-I DIV-II DIV-IIa DIV-IIb

DIVERTOR NAME

PL/Pth1

50 100 150 200

MK0 MKIIGB MKSRP

MkI MkIIa MkIIap

MK0 MKIIGB

MKSRP MkI MkIIa MkIIap

0.1 0.06

1 0.6 0.4 0.2

10 6 4 2

.1 .07 1 .8 .6 .4 .3 .2 10 7 5 4 3 2

Pth4

PL

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 9

Effect of Divertor IIEffect of Divertor II

Scaling with one divertor for JET (MkIIap):

Pth4 = 2.96 ne200.85 BT

0.51 a1.07 R0.83

RMSE = 22.9%

Scaling with three divertors for JET (Mk0, MkI, MkIIap):

Pth4b = 2.96 ne200.84 BT

0.63 a0.89 R1.02

RMSE = 25.5%

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 10

Effect of PhaseEffect of Phase

Remove 'bad' Phases (LDL, OHMH, ...)

Scaling:

Pth5 = 2.34 ne200.67 BT

0.62 a1.02 R0.71

RMSE = 21.5%

... little improvement, but 'good' one for conventional tokamaks

0.4 0.6 0.8

1 1.2 1.4 1.6 1.8

2

D DH LD LDL LH OHMD OHMH

PHASE

PL/Pth4

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 11

Normalisation of device contributionsNormalisation of device contributions

Random selection of data in 'over-represented' devices

Scaling:Pth5b = 2.39 ne20

0.63 BT0.64 a1.07 R0.65

RMSE = 21.2%

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U PBXM TCV

25 50 75 100 Count

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U PBXM TCV

20 40 60 Count

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 12

Normalisation of device contributionsNormalisation of device contributions

Including weigths for data

Scaling:

Pth5c = 1.82 ne200.57 BT

0.67 a0.87 R0.79

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 13

Effect of aspect ratio - Spherical tokamaksEffect of aspect ratio - Spherical tokamaks

Including Spherical TokamaksRequire aspect ratio characterisation

• 3 parameters to describe shape• a or R, kappa or S, R/a or Rmm=(R+a)/(R-a)

Scaling:

Usual parameter setPth6 = 3.73 ne20

0.55 BT0.60 a1.43 R0.18

RMSE = 24.5%

New parameter setPth7 = 0.151 ne20

0.63 BT0.67 R1.22 S0.25 Rmm

1.21

RMSE = 22.9%

ASDEX AUG CMOD COMPASS D3D JET JFT2M JT60U MAST NSTX PBXM TCV

25 50 75 Count

0.1 0.06

1 0.6 0.4 0.2

10 6 4 2 PL

.1 .07 1 .8 .6 .4 .3 .2 10 7 5 4 3 2

Pth7

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 14

Low densityLow density

Select low density data from each device

Device Density [1020m-3]ASDEX 0.27AUG 0.35CMOD 1.2 JET for instance:Compass 0.6DIII-D 0.4JET 0.2JFT2M 0.3JT60U 0.25MAST 0.275NSTX 0.25PBXM 0.3TCV 0.55

1 2 3 4 5 6 7 8 9

10 11 12

PL

.1 .2 .3 .4 .5

ne20

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 15

Low density IILow density II

Scaling:

Pth8 = 2.23 ne200.385 BT

0.63 a1.18 R0.27

RMSE = 26.1%

0.1 0.06

1 0.6 0.4 0.2

10 6 4 2 PL

.1 .07 1 .8 .6 .4 .3 .2 10 7 5 4 3 2

Pth8

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 16

Prediction for ITERPrediction for ITER

Predictions with all developed scalings

Prediction - confidence interval: on average, individual

Some scaling less reliable (usual parameter set, with STs)Some scaling reliable: #5: usual parameter set, conventional tokamaks#7: extended parameter set, with STs

Prediction at 2 densities: 0.6 and 1.0 1020m-3

Scaling ne20 Predicted LH threshold power [MW]#5 0.6 22 32 35 38 53#5 1.0 31 42 49 56 76#7 0.6 22 32 35 39 55#7 1.0 30 41 48 56 77

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 17

ConclusionConclusion

New data added

Enlarged data set

Scaling with selected divertors

Scaling with selected phases

Aspect ratio effect

Low density threshold power

Prediction for ITER

Yves Martin, ITPA TG CDBM LH Transitions, March 2004, Naka 18

New - to be incorporatedNew - to be incorporated

Scaling with other divertors• 'bad' divertors• all combinations

Dimensionally correct scalings

Discuss density value for ITER• include access to appropriate ELMy regime

Compare / discuss 'new' vs 'old' scalings• F.Ryter, J.Snipes, T.Takizuka