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1313thth ITPA Transport Physics Group Meeting ITPA Transport Physics Group MeetingNaka, 1-3 October 2007Naka, 1-3 October 2007

V. MukhovatovV. Mukhovatov

ITER Rotation IssuesITER Rotation Issues

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan2

Plasma RotationPlasma Rotation

• Plasma rotation important for nearly all ITER plasma characteristics

Energy confinementNTM stabilityRWM stabilityDisruptivity

• Usual approach at present: Neglect intrinsic rotationNBI momentum input with =

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan3

Three Major Recent AdvancesThree Major Recent Advances

• Scaling for intrinsic rotation – J.Rice

• Demonstration of additivity of NBI induced rotation and intrinsic rotation – DIII-D

• Demonstration of low rotation required for RWM stability at low error field – DIII-D and JT-60U

All three are favourable for ITER!

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan4

A.Polevoi et al Nucl. Fusion 45 (2005) 1451

Plasma Rotation in ITER at = i

ASTRA Code Predictions

Inductive mode Improved Hybrid mode Steady State mode

HH98(y,2) = 1 HH98(y,2) = 1.2 HH98(y,2) = 1.31

PNB=33MW PNB=33MW PNB=33MW

PRF=7MW PECCD=34.5MW

Inductive: ftor(0) = 1 kHz

Steady state: ftor(0) = 3.4 kHz

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan5J. Rice, 12th TP ITPA Meeting, Lausanne, 7-10 May 20077-10 May 2007

ftor ~ 9 kHz

ftor ~ 4 kHz

ITER

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan6

Intrinsic Rotation in ITERIntrinsic Rotation in ITER

• Rice scaling predicts 3-4 times higher rotation rate in ITER compared to that expected from planned two NB injectors (16.5MW/1MeV each)

• Predicted intrinsic rotation is equivalent to torque produced by seven additional ITER-like injectors with total power above 100 MW

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan7

Intrinsic Rotation in ITER: Intrinsic Rotation in ITER: UncertaintyUncertainty

• Uncertainties in predicted intrinsic rotation for ITER are, however, quite large

• To reduce the uncertainty additional experiments, guidelines from first-principle theory and theory-based simulations are required

• Re-analysis of available data assuming / i = 1 for NBI induced rotation and considering extra rotation as intrinsic one may be useful

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan8

Comparison of Momentum and Ion Thermal Comparison of Momentum and Ion Thermal Diffusivities in NB only Heated PlasmaDiffusivities in NB only Heated Plasma

D. Nishijima et al Plasma Phys. Control. Fusion 47 (2005) 89

ASDEX Upgrade

<i manifests on the presence of intrinsic rotation (?)

/I = 0.3-0.15

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan9

Energy Confinement Energy Confinement Low Effect of ExB Shearing Rate on Plasma

Performance in ITER Hybrid Scenario

R. Budny and C. Kessel (PPPL)ITPA Saint Petersburg, Russia, October, 2005

Intrinsic rotation neglected

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan10

Effect of Plasma Rotation on NTMsEffect of Plasma Rotation on NTMs

A.M. Popov, 33rd EPS Conference on Plasma Phys. Rome, 19 - 23 June 2006 ECA Vol.30I, P-1.106 (2006)

Simulations on NTMs in ITER with nonlinear 3D MHD code NFTC:• in the absence of error fields, single 3/2 mode is stabilized by rotation• In the presence of m/n=1/1 error field, rotation stabilizes 3/2 NTM and destabilises 2/1 NTM

13th ITPA Transport Physics Group Meeting, 1-3 October 2007, Naka, Japan11

SummarySummary

• Assumption = i underestimates toriodal rotation rate in ITER

• Rice scaling predicts intrinsic rotation in ITER several times higher than expected from NBI, although uncertainty is large

• Additional experiments, guidelines from first principle theories and theory-based simulations are required to improve accuracy of rotation predictions for ITER

• Structure of intrinsic toroidal rotation, V(r,), is required

• Rate of intrinsic poloidal rotation is necessary