統合コード 研究会
九大応力研, 2004/3/19

MHD、ディスラプションとその制御に関する
第 4 回 ITPA 会合の報告
N. Nakajima
NIFS• 会合の概要◦ US/JP ワークショップ ”MHD stability control of toroidal plasmas”◦ Large Tokamak ワークショップ ”Physics of current hole”◦ 第 4 回 ITPA Topical Group 会合 ”MHD, Disruption and Control”
Tokamak Physics Basis の執筆内容の検討が主体• 議論における注目点• 物理サブクラスターの活動に関して

Feb. 2, Ver.10 final
US/Japan workshop on “MHD Stability Control of Toroidal Plasmas”(FP2-2),
Large Tokamak workshop on “Physics of Current Hole” (W56)
and The Fourth Meeting of the ITPA Topical Group on MHD, Disruption and Control
Naka JAERI, Japan
MONDAY,2

FEBRYARY

2 – 6 February 2004

ITER Conference Building

8:50 Registration
9:00 Welcome address : M.Kikuchi (JAERI)
9:05 K.Yamazaki(NIFS), Opening of workshop on US/Japan workshop on MHD Stability
Stability in helical system and control
Chairman: K.Yamazaki
9:15 E. Lazarus (ORNL): Plasma Control Requirements for the NCSX Stellarator
9:45 K. Watanabe(NIFS): The effects of Ideal Interchange Mode on Operational Regime in LHD Experiments
10:15 Y. Narushima (NIFS): MHD stability of LHD plasma with large plasma current
10:45 E. Lazarus (ORNL): Design of Magnetic Equilibrium Diagnostics for Stellarators
11:15 C.Suzuki (NIFS): Effect of Toroidal Current on MHD Stability for N=2 Quasi-Axisymmetric Stellarator
11:45 N.Nakajima(NIFS): Ideal MHD spectra in Heliotron system
Lunch 12:15 – 13:15
Stability in innovative confinement concept
Chairman: E.Lazarus
13:15 J. Manickam (PPPL): Role of fast plasma rotation on MHD physics in NSTX'
13:45 A. Ishida (Niigata Univ): Theory of Flowing Two-Fluid Equilibrium and Its Application to ST
14:15 E. Fredrickson (PPPL): MHD issues in NSTX
14:45 N.Mizuguchi (NIFS): MHD properties of spherical torus plasma with flow
Break 15:15 – 15:30
Non-ideal and Non-linear MHD Stability Behavior
Chairman: J.Manickam
15:30 S.Yamaguchi (Kyoto Univ): Three Dimensional Observation of Sawtooth Crashes by Multi-Toroidally-Positioned SXCT system
16:00 E. Lazarus (ORNL): Comparison of Sawteeth in Bean and Oval Shaped Tokamak Plasmas
16:30 Y. Ishii (JAERI): (tentative) Non-linear simulation of double tearing mode
16:50 Martynov (by Jo Lister)(CRPP): edge kink mode stability with a separatrix
Adjourn 17:10

Feb. 2, Ver.10 final
TUESDAY, 3 FEBRUARY,
ITER Conference Building
Neoclassical Tearing Mode and Steady State Issues
Chairman: E.Strait
9:00 R. La Haye (GA): ECCD Suppression of NTMs in ITER
9:30 A.Isayama (JAERI): NTM and Steady State experiments in JT-60U
10:00 S. Guenter: Active control of MHD instabilities on ASDEX Upgrade
10:30 S. Konovalov (JAERI/ Kuruchatov): Theory of magnetic well and anomalous transport effects on NTM
10:50 N. Hayashi (JAERI): NTM simulation and prediction for ITER
Break 11:10-11:20
Stabilization and Destabilization by Wall, Error Field, Rotation and Others
11:20 E. Strait(GA): RWM stabilization with internal coils in DIII-D
11:50 R. Granetz (MIT): Locked mode studies on C-Mod

Chairman: G.Navratil

Lunch 12:10-13:10
Chairman: R.Granetz
13:10 S.Tokuda/Aiba (JAERI): External mode analysis by MARG2D code
13:30 M.Furukawa(JAERI): A model equation for ballooning modes in toroidally rotating tokamaks
13:50 S. Jardin (PPPL): Mode rigidity of RWM
Break 14:20 – 14:20
Chairman: S.Guenter
14:20 M.Sato(NIFS): Nonlinear simulation of resistive wall modes in cylindrical tokamaks
14:40 J. Bialek (Columbia Univ.): VALEN code simulation on RWM
15:00 G.Kurita (JAERI): RWM Analyses with Ferromagnetic and Plasma Flow Effects in a Tokamak
15:20 G.Navratil (Columbia Univ.): VALEN/DCON Study of RWM Rigidity and Extension to Multi-Mode Analysis
15:40 V.D. Pustovitov(Kuruchatov): Comments on the Single Mode Model Used in VALEN Calculations
Break 16:00 – 16:20
16:20 T.Ozeki(JAERI): Opening of workshop of Current Hole
Chairman: T.Ozeki
Equilibrium and MHD Stability of Current Hole
16:30 S. Guenter(IPP): Current hole equilibria with self-consistent current density profiles
17:00 R. Jayakumar (LLNL): Current hole Equilibrium Model of Current Hole

Adjourn 17:30
Party on Akogi-Club ( 2000yen per person )Feb. 2, Ver.10 final
WEDNESDAY, 4 FEBRUARY
ITER Conference Building(continued)
Chairman: R.Jayakumar
9:00 T. Takizuka (JAERI): Axi-Symmetric Multi Islands equilibrium
9:30 S. Jardin (PPPL): Modeling of current hole plasmas
10:00 S.Cortes (IST): Current hole studies with and without equilibrium reconstructions at JET tokamak
10:30 R.Kanno (NIFS): LHD equilibrium with Zero Rotational Transform Surface
11:00 G.Huysmans(CEA): MHD Stability Simulation of Current Hole plasmas
11:30 Y.Nakamura(JAERI): TSC Simulation of Current Hole
11:50 Martynov (by Jo Lister)(CRPP): tokamak equilibria with negative core current calculated withaxisymmetric islands
12:00-12:15 Summary of MHD workshop: G.Navratil
Lunch 12:15 - 13:15
Observation of Current Hole and Related Phenomena
13:15 N. Hawkes(UKAEA): Current Hole Studies at JET
14:00 T. Fujita(JAERI): Experimental Studies on Current Hole in JT-60U
14:45 O.Gruber(IPP): Observation of current holes in ASDEX Upgrade

Chairman: G.Huysmans

Break 15:15 - 15:30
Chairman: G.Hawkes
15:30 K.Toi(NIFS): Exploration of New Magnetic Configuration with Zero Rotational Transform in the Large Helical Device
16:00 R. Jayakumar (LLNL): Curerent hole Experiments in DIII-D
16:30 N.Hayashi(JAERI):Transport Simulation of Formation and Sustainment of Current Hole
17:00 Discussion on application of current hole towards reactor:
Summary of Current hole workshop: T.Fujita (JAERI)
Adjourn 17:30

Feb. 2, Ver.10 final

THURSDAY, 5 FEBRUARY
JT-60 Building
Fourth ITPA Topical Group meeting on “MHD, Disruption and Control”

Chairman: O.Gruber

9:00 - 12:00 Presentation of the sections of chapters 3&8 of the Tokamak Physics Basis(15min Coffee break)
12:00 -13:00 Lunch
13:00 - 17:30 Presentation of the sections of chapters 3&8 of the Tokamak Physics Basis (continue)(15min Coffee break)
Adjourn 17:30
FRIDAY,6

FEBRUARY

JT-60 Building

9:00 -10:30 Presentation of the sections of chapters 3&8 of the Tokamak Physics Basis (continue)
10:30 10:45 Coffee break
Review of recent experimental and theoretical results (Disruption and Control)
10:45 V.Lukash: DINA code fitting of halo current in intentional JT-60U VDE shots (15 min)
11:00 R.Yoshino: Neural-Net Disruption Predictor in JT-60U. (15 min)11:15 E. Lazarus: Thoughts on the gain matrix for plasma shape control (15 min)
11:30 V. Pustovitov: Comments on the Single Mode Model Used in VALEN Calculations (15 min)
11:45 J. Lister: Testing a magnetic correction to position drift using DINA-CH(10 min).
12:00 -13:00 Lunch
13:00 Y. Gribov: Present status of the Electronic Working Group on Control"
14:00 - 15:30 Discussions on joint international experiments
15:30 - 15:45 Coffee break
15:45 - 17:30 Other topics
Adjourn 17:30(about 30min)

SUMMARY OF US/JAPAN WORKSHOP
G. A. Navratil
Columbia University, NY, USA

US/Japan Workshop on
MHD Stability Control of Toroidal Plasmas
JAERI-Naka, Japan
2-6 February 2004

Helical Systems• QUASI-AXISYMMETRY STELLARATORS:NCSX(BUILDING) AND CHS-QA(PROPOSED)• SEEKS TO COMBINE THE “BEST” FEATURE OF
TOKAMAK AND STELLARATOR:COMBINE BENEFIT OF TOROIDAL ROTATIONTHRU QA WITH DISRUPTION RESISTANCE OF
EXTERNAL MAGNETIC TRANSFORM.
• LHD STUDY MHD & CONFINEMENT PROPERTIESMHD Activity in Ideal Interchange Unstable Region
Pressure gradient just after pel. inj(0.75, 2.8T)

Achievement of pressure gradients in theregion predicted as ideal MHD unstable==> observation of saw-tooth oscillation as
fluctuation signal=> Achievement as Transitional State=> Possibility of Achievement in
Stationary ????

Effects of resonant fluctuations on global confinemets in LHD
Disappearance of only coreresonant flucuation

Disappearance of both coreand edge resonant flucuations#31811 (more stability unfavorable conf. than 3.6m)
Rax=3.5m, B=0.5T, H2-gaspuff-only
NB-heating(Co4.0MW,Cntr1.2MW)#16964
Rax=3.6m, B=0.75T, H2-gaspuff-only
NB-heating(Co2.1MW,Cntr0.9MW)

a NBI line; break-down

B/B0

B/B0

0

1.0

2.0

3.0 (s)After core resonant mode disappears,
peripheral resonant mode disappears

Impact on Wp ~5%

Impact on Wp ~30%

Core resonant fluctuation disappears because the resonant mag. surf. disappears due to toroidal current.

ST Systems• SEEKS TO OPTIMIZE TOKAMAK THROUGH LOW A:
HIGH BOOTSTRAP CURRENTLARGE FLOW VELOCITY & FLOW SHEARLARGE MAGNETIC SHEARLOW FIELD & LOW ALFVEN SPEED• BRIDGES TOKAMAK PHYSICS BASE & TOOLS TO
LOW A REGIME.

Rotation effects evident in ne(R) profiles• Most easily seen in MHD-quiescent L-mode discharges• Single-fluid MHD force balance:

J × B = ∇p + ρv•∇v ⇒– Near axis, J × B small ⇒R/p ∂p/∂R = MS2 = 2MA2 / βMS ≡ vφ / vSound
MA ≡ vφ / vAlfven

T e = T e(ψ)∇ne(ψ=0) ≠ 0

Maximum
ne off-axis107540 at
t=330ms

Te (keV)• Ms = 0.4-0.7 ⇒ne (m-3)
4x1019– strong impact on equilibrium• Similar to standard tokamak

Magnetic axis

local

MA

• MA = 0.15-0.4 ⇒– strong impact on stability• 2-3 × larger than standard tokamak
US-Japan MHD Workshop, J. Manickam, Feb. 2, 2004

7

Numerical solution
Ï *r2
r 3yr 2¢scheme ÔD y = 2 ( pz y z + pr yr ) - FF 2 f
—y
—y
Ô
Ô
yr *
Ì pr = - 2 (D y + FF¢) - rf 2
divr
Dp = -fÔyz *Ô
solve two( ) Poisson's eqs.
Ô pz = - r 2 (D y + FF¢)Ó
simultaneously by iterations†

example of solution
†

Z

1

0

y
p

-1

.4

.6

.8

1R

Elevated q sustains operation above no-wall limit• Increase q the old-fashioned way:
– Raise field from 0.3T to 0.5T + early H-mode– Decrease current to 0.8MA ⇒ fBS → 50%

conducting
plates• Operate with βN > 5 for ∆t > τCR=0.25s– No rotation slow-down or evidence of RWM
Plasma109070computed

109070t=530ms

Expt.
value
of β N• Stabilization of RWM with rotation+dissipation demonstrated on DIII-D• Compare NSTX RWM predictions to DIII-D using MARS code
US-Japan MHD Workshop, J. Manickam, Feb. 2, 2004

16

NTMs seen in high performance
NSTX discharges• Roll-over in b starts withbeam power stepdown.
• No chirps, but beams offearly in mode.
• Interestingly, no clear
trigger, early large
frequency jump.
• Accompanied later in timeby core n=1 ideal mode

Tokamak Systems• SEEKS TO OPTIMIZE TOKAMAK THROUGHCONTROL OF MHD:
NTM
RWM
ELM

ACTIVE TRACKING OF RATIONAL SURFACE ALLOWSSTABILITY ABOVE THE PREVIOUS NTM LIMIT●

Feedback system adjusts RSURF to minimize mode amplitude (“search and suppress”)● Active tracking keeps ECCD at the q=3/2 surface in the absence of the mode
— Compensates for the Shafranov shift as beta increases● Mode does not reappear when β is raised above the initial stability limit
3.0
2.0

114504

βN

1.0

BEAMS
STEPPED UP

0.0

βN > βN, onset
and NO reappearanceof 3/2 NTM

0.0 δRSURF (cm) Feedback optimizes
radial position

–1.0
–2.0
8.0

“Active Tracking”
adjusts position
n=2 rms (G)3/2 NTM
suppressed∆R=1.7 cm
inboard

Sawteeth

3/2 NTM

0.0
1500

2000
3/2 NTM
onset

DIII–D

2500

3000
3500
Time (ms)rf on (4 gyrotrons)

4000

4500

5000
discharge
programed off

NATIONAL FUSION FACILITYSAN DIEGO

010-04/jy

NTM growth and its stabilization by ECCD in JT-60U experiments
NTM island growth ( E36705 )Stabilization by ECCD ( E41666 )Fundamental O-mode EC wave of 110GHz
was injected to 3/2 mode NTM.

m/n=3/2 mode NTM grew from t=6.4 s
and was saturated at t=7.2 s.
Normalized beta was decreased by about
10%.

Real-time control of the EC current location( island is detected from Te perturbation )could completely stabilize the NTM.

Ip=1.5MA, Bt=3.7T

E036705|B|[arb.] PNB[MW]|B|[arb.] PNB [MW]A.Isayama, et al. 19th IAEA conf.
20
ECH(~1-1.5MW)

0

n=2
(m=3)

0
1

n=2
(m=3)

bN

bN

ECCD(~3MW)

0
1.8

2

1.5

1
0

30

Ip=1.5MA, Bt=3.7T, q95=3.9

E041666

1.3
5

6

7
time[s]

8

9

1.67
6

7

8

9
time[s]10

11

CONCLUSIONS FOR ITER●

Proposed 20 MW, 170 GHz, “high launch” system★ at best adequate to control either or both the 3/2 and 2/1 NTMs
★ good alignment and modulation can keep both islands small. . . Prf ≈ 16 + 10 ≈ 26 MW injected power— for –2% and –4% energy loss respectively●

Additional focusing and/or a lower launch should be investigated★ for a narrower, better matched current drive. . . requiring lower rf power●

A full sensitivity study on wmarg, δec and ∆′r remains to be done●

Existing devices need to prove out modulation (ASDEX UPGRADE?)★ and prove out role of δec on Prf (DIII–D 2004)

010-04/jy

Necessary EC current much depends on the parameters of bootstrap
current and ECCD terms in the modified Rutherford equation.
Dependence of Ifs0 on kBS and Wd is strong, while that on kpol are rather weak.
Value of WES increases with Wd, while that is not much varied by kBS and kpol.

I fs0 µ 1 k EC

From modified Rutherford eq.,

Ifs0 / Ifs00

kpol=1, Wd=0.01

1

0

0.03

2

WES
0.02

1

WES~0.01
2

3

4

5
kBS

6

7

original
Wd

0
0

Ifs0

WES

Ifs0 / Ifs00

2

0.01

with flux-limit
0.01

Wd

0.02

0

For kBS~4, kpol~1, kEC~4, Wd~0.01 estimated from JT-60U experiment,
Ifs0 ~ 74 kA for 3/2 mode and ~ 54 kA for 2/1 mode on ITER ( error~20% ) .
PEC(MW) ~ 0.23 IEC(kA) for 3/2 mode
EC code results :~ 0.24 IEC(kA) for 2/1 mode
ECCD power necessary for both 3/2 and 2/1 modes NTM stabilization on
ITER is 30 MW.
Necessary ECCD power can be reduced to 12 MW when the EC current widthis half decreased by optimizing both toroidal and poloidal injection angles.
WES~0.01 (2 cm) is small for early stabilization.

NTM control by sawtooth mitigation (off-axis-ECCD)

Co –ECCD:• no sawteeth as expected• Reduced fishbone amplitude• NTM triggered after ECCD (by ST)

Counter-ECCD:• NTM triggered by FB during ECCD

Control of ELM frequency by pellets• small pellets (2 … 3x1019 D atoms, not strong fuelling)• Confinement degradation ~ f-0.16(less than for frequency change by, e.g., heating power or gas puff)

FEEDBACK CONTROL WITH INTERNAL COILSSTABILIZES RWM WITH LOW ROTATION● Magnetic braking reduces rotation to zero in the outer half of the plasma● Feedback with internal coils maintains stability for >100 ms● Case without feedback becomes unstable at lower beta, even with rotation

4114340 114336

βN/li

Ideal-Wall
Limit

Feedback

3

No-Wall Limit25(approx.)21143361390 ms

Rotation
Frequency (kHz)20

1

No-Feedback

15

15

Feedback
Stabilizedwith Low
Rotationfrot (kHz) at ρ = 0.6

9
3
150

30

δBp (Gauss)

DIII–DNATIONAL FUSION FACILITYSAN DIEGO

5
0
0.0

50
1000

10

1143401500 ms

0.2

0.4

0.6

0.8

1.0

ρ

1200

1400
Time (ms)1600

236-03/rs

FEEDBACK WITH I-COIL CAN CONTROL RWM GROWTH
CLOSER TO THE IDEAL WALL LIMITO Observed growth rate of unstable RWM is consistent with VALEN calculation
No-Wall
Limit

Ideal-Wall
Limit

12
No Feedback
External Control Coils (C-Coil)Internal Control Coils (I-Coil)

10

γτw

8
6

VALEN

4
2
0

2.0

2.5

3.0
β /li

3.5

4.0

N

DIII–DNATIONAL FUSION FACILITYSAN DIEGO

238-03/rs

Alcator
C−Mod

Comparison with Prior Scalings
LaHaye 1997 strong size scaling is contradicted by C-Mod
Scaling developed by comparing Compass/DIII-D/JET data.

Supported by theory-based arguments for Block ∝ R−9/5
C-Mod locking threshold is factor > 10 below scaling,∼ same fractional value as for
DIII-D and JET.

Locking Threshold Scaling (LaHaye 97)
10–2

CRITICAL √ (Wm1 *B2⊥m1) / BT FOR LOCKED MODE

Experimental scaling of threshold with size appeared very bad
for ITER.

.

(q95 ≈ 3.5, OHMIC, DEUTERIUM,
nπa2 / I ≈ 0.2 x 1020 m–3 x m2 / MA)
COMPASS-C
Combined Error Field Scalingm,n = 1,1 2,1 & 3,1

10–3
Original scalingm,n= 2,1

DIII–D
10–4

10–5
0.1

C−Mod

1.0

JET

10.0

Major Radius, Ro (m)[Compass data different from others, has very strong inverse Bt scaling.]

VALEN Results for ITER
Feedback Performance With Internal Coils
10 6

g-passive no ports 3.0

feedback system:
Vcc = Gp * ( poloidal flux in sensor )

[1/s]

10

no bl 45 ports
9 ms bl 45 ports

55 ms bl 45 ports
45 ports&tub
9ms bl 45 ports&tub

10 4

g FB tub 10^7

growth rate

g FB tub 10^8

10 3
10 2
Gp=10^8

10 1
Gp=10^7

10 0

10

beta-normal

- 1

2.0

3.0

4.0

5.0

Data from "ITER.01.2004.w.betan"

SUMMARY / CONCLUSION• For the n=0 RWM, it was shown that the plasma can deform in
response to the feedback system, and this needs to be taken
into account in the detailed design of a feedback system• For the n=1 RWM, the plasma will also deform in response to
the feedback system. For the NMA analysis, this is equivalent
to keeping “stable” modes in the analysis of the unstable modewith feedback• MARS should have this effect included and agrees with NMA inbenchmarking• VALEN does not include this effect; there should be a detailed
comparison between VALEN and NMA/MARS to assess theimportance for ITER
13

SMALL VARIATION IN MODE WITH BETA
Bn #1 @0 30

0.5

Bn #1 @0 40
Bn #1 @0 50
Bn #1 @0 60

0.4

Bn #1 @0 70

Bn #1 @0

[ T ]

0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
0

1

2
arc length [m]34

We need the definitions to start the benchmarking

− δW
s=
2
LI / 2()

What is L ?
What is I ?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

s is not a generally accepted parameter.
However, it plays important role in the theory used in VALEN code:
A. H. Boozer, Phys. Plasmas 5, 3350 (1998).
A. H. Boozer, Phys. Plasmas 6, 831 (1999).
A. H. Boozer, Phys. Plasmas 6, 3180 (1999).
J. Bialek, A. H. Boozer, M. E. Mauel, and G. Navratil, Phys. Plasmas 8, 2170 (2001).
A. H. Boozer, Phys. Rev. Lett. 86, 5059 (2001).
A. H. Boozer, Phys. Plasmas 10, 1458 (2003).
A. H. Boozer, Phys. Plasmas 11, 110 (2004).
4

D3He Mountain

Clarify
Common Phenomena,
Common Physics Identification,
Common Scaling etc.!

DT Mountain

DEMO 2030
ITER
RWM

2010

NTM

2004

Common MHD Issues

Helical1951

Tokamak

ST,RFP,CT

Summary of Large Tokamak workshop on “Physics of Current Hole” (W56)
JAERI Naka, Japan Feb. 3-4, 2004.
l Equilibrium
m=1or2/n=0 islands (Martynov), m=2/n=0 islands (Takizuka)
Complete j(0)=0 equilibrium (Chu)
3D-code; iota=0 in helical systems (Kanno), tokamak eq. w. VMEC
(IPP-Garching)
BS current in a current hole (Chankin)lStability and sustainment mechanism
Axi-symmetric event (Huysmans)
Finite beta effect (Jardin)
In above two, stationary state with flow is realized for limited
conditions.
Radial flow with NB (Jensen)lTransport simulation
Oscillatory behavior in q(r) and p(r) (TSC, Nakamura)
Neoclassical ITB + CH (TOPICS, Hayashi)-1-

lExperiment

JET; LFS-localized beam ions, off-axis sawtooth
JT-60; current clamp for positive/negative CD, less stiff Te(r)AUG; CH in NB ion ITB and on-axis ctr-ECCD
LHD; zero iota with counter NBCD, off-axis peak in Te.
DIII-D; NCS->CH, EFIT and MSE improved, RWM study.
lReactor application and related studies

Is CH generated ITER? -> Scaling for formation conditions frommulti machine experiments.
Confinement of alpha/NNB particles, MHD/AE stability,
Controllability, Impurity accumulation, Transport scaling, ...
lFuture directions in physical studies

Neoclassical theory in CH (bootstrap, conductivity (σ, χ), ...)
Nonlinear MHD simulation for more relevant to experiments.
Can experiments be reproduced with MHD simulation only or istransport modeling also needed?
What can be done in experiments? (local heating, 2D camera
diagnostic, more accurate Bp/Te/Vp measurements,fluctuation
measurements, ...)
-2-

ITPA における課題
緊急で重要度の高いもの• NTM 低ベータでのベータ値向上を制限するものとして
1. NTM による磁気島の安定化と高ベータ化へ（ 主に ECCD による）
2. NTM の発生機構と制御（ Sawteeth や誤差磁場等による発生とその制御）
3. NTM の理論モデルと実験的検証
4. ITER での NTM の制御シナリオ、制御システムへの要求• RWM 高ベータ達成への障害として
1. RWM 安定化の実験と理論モデル
2. RWM 安定化への回転、誤差磁場等の影響
3. ITER での RWM の予測と、制御システムへの要求• ディスラプション 回避すべき対象として
1. ディスラプションデータベース（ 負磁気シアプラズマを含む）
2. キラーペレット、ガスジェット入射等によるディスラプション緩和技術開発（ ハロー電流、遁走電子抑制、制御を含む）

Issue:2

CHAPTER 3
MHD STABILITY, OPERATIONAL LIMITS AND DISRUPTIONSTABLE OF CONTENTS
Participants of the fourth ITPA meeting on MHD, Disruption and Control are marked in red.

3. MHD STABILITY, OPERATIONAL LIMITS AND DISRUPTIONS
90 pages of A4 format (in IPB it was 254)
- proposed authors by the TG on M,D&C are listed;- proposed leading authors are underlined;- listed authors, who have not yet agreed, are put in green.
3.1.

INTRODUCTION
2-3 pages(Including summary of the results from ITER Physics Basis : chapter 2.1 Ideal MHD
Stability limits and chapter 3.1 Disruptive Density Limits ; organization of this chapter)
O.Gruber, E.Strait, T.Ozeki

3.2.

MHD STABILITY

3.2.1. Sawtooth Oscillations(Note: the section on fishbones is removed from chapter 3 to chapter 5, not yet negotiated)
3.2.1.1.
Physics of sawtooth oscillations
2 pages
L.Zakharov, F.Porcelli, O.Sauter

3.2.1.2.

(Note: the effect of fast particles on sawteeth will be treated in this section)
Control of sawtooth oscillations (ECRF, ICRF, NI)4 pages

3.2.1.3.

Central MHD activity expected in ITER and their control

T. Goodman, E.Westerhof, A.Isayama, O.Sauter, H.Zohm
S.Jardin, G.Pereverzev, B.Goodmann, L.Zakharov

Page 1 of 6

2 pageIssue:2
3.2.2. Neoclassical Tearing Modes
3.2.2.1.

Physics of NTMs (including thresholds and power ramp-down)

3 pagesO. Sauter, C.Hegna, T. Ozeki, S. G nter, R. Buttery, H.Wilson, S.Jardin

3.2.2.2.

Active Control of NTMs

4 pages

H. Zohm, A.Isayama, R.. LaHaye, R.Buttery

3.2.2.3.

Mitigation of NTMs (sawtooth suppression, FIR mode)

4 pages

S. G nter, O.Sauter,3.2.2.4.

NTMs expected in ITER and their control

2-3 pages

R. LaHaye, G. Giruzzi, S. G nter, A.Zvonkov, B.Lloyd, A.PopovN.Hayashi

3.2.3. Resistive Wall Modes
3.2.3.1.

Physics of RWMs (includ. role of rotation and error fields)

4 pagesA.Bondeson, E.Strait, G.Navratil, A.Garofalo, T.Hender, M..Takechi, A.Boozer

3.2.3.2.

Control of RWMs

4 pages

E.Strait, G.Navratil, M.Okabayashi, V.Pustovitov

3.2.3.3.

RWM expected in ITER and their control

3 pagesY.Gribov, A.Bondeson, G.Navratil, V.Pustovitov

3.2.4. Physics of ELMs: Edge Stability
H.Wilson, G.Huysmans, Snyder, L.Lao, L.Horton, S.G nter, T.Oikawa, L.Villard

3.2.4.1.
Edge stability (types I,II,III ELMs)
3.2.4.2.
Expectation for ITER
(Active control of ELMs via pellets, edge currents, . in Section 5)<5 pages
1-2 pages

3.2.5. Error Fields
3.2.5.1.

Effect of error fields on plasma (locked modes, NTMs, RWM: see 3.2.3.1) 3 pages
T.Hender, R.Buttery, R. LaHaye, R.Fitzpatrick, E.Lazzaro, Sato

3.2.5.2.

Error fields expected in ITER and their correction

2 pagesY.Gribov, T. Hender

Page 2 of 6

Issue:2
3.2.6. MHD Stability in Advanced Scenarios
3.2.6.1.

MHD stability in plasmas with weak magnetic shear (q0˚= 1˚-˚2)

2 pagesJ. Manickam, E.Strait, T.Ozeki, G.Huysmans

3.2.6.2

MHD stability in plasmas with strong negative magnetic shear (qmin˚= 1.5 —2.5) 4p.

3.2.6.3.

Expectations for ITER

T.Ozeki, S.Jardin, A.Turnbull, C.Kessel, H.Zohm, T.Hender

2 pages

S.Medvedev, C.Kessel, T.Ozeki, J. Manickam

3.2.7. Summary

2-3 pages
E.Strait, H.Zohm, T.Hender, T.Ozeki

3.3.

DISRUPTIONS
O.Gruber, M.Sugihara, R.Granetz, Y.Kawano

3.3.1

Disruption Characterization
3-4 pages(causes and mechanisms, major disruptions and connected vertical displacements,
disruptions due to vertical instability VDE , thermal and current quenches, neutral
point , waveform of plasma current)
V.Riccardo, M.Sugihara, R.Granetz, Y.Nakamura (neutral point), G.Pautasso, S.Mirnov, A.Hyatt, D.Gates

3.3.2

Thermal Loads

4 pages
G.Pautasso, G.Federici, D.Whyte, N.Asakura, P.Andrew

3.3.2.1.
3.3.2.2.
3.3.2.3.
3.3.3

Thermal loads during thermal quench
Thermal loads during current quench
Expectation for ITER

Halo Currents and Mechanical Forces(asymmetries, vertical / radial forces )2 pages

R.Granetz, Y.Kawano, D.Humphreys, G.Pautasso, V.Riccardo

3.3.3.1.
3.3.3.2.
3.3.3.3.

Major disruptions
VDEs
Expectation for ITER (in fact, results of the simulations (ch. 3.3.5) will enter)

Page 3 of 6

Issue:2
3.3.4. Runaway Electrons Generated by Disruptions

3 pages

Y.Kawano, V.Riccardo, D.Humphreys, P.Helander

3.3.4.1.
3.3.4.2.
3.3.4.3
3.3.4.4

Generation of runaway electrons
Interaction of runaway electrons with plasma facing components
Mitigation of runaway electrons
Expectation for ITER

3.3.5.

Simulations of Disruptions in ITER

3-4 pages

M.Sugihara, S.Jardin, V.Lukash, Y.Nakamura

3.3.5.1
3.3.5.2
3.3.5.3

ITER disruption simulations (disruption guidelines, simulator)
Predictions for major disruption
Predictions for VDEs

3.3.6. Disruption Avoidance, Prediction and Mitigation
3.3.6.1.

Disruption predictions (locked modes, neural nets,..)3 pages

P.Sonato, G.Pautasso R.Yoshino, Lewer

3.3.6.2.

Disruption avoidance

3 pagesV. Mertens, E.Strait, A.Kellman R.Yoshino, V.Riccardo

3.3.6.3.

Disruption mitigation (impurity killer pellets and gas puffs)

4 pages

D.Humphrey, D.Whyte, G.Pautasso, Y.Kawano, P.Andrew

3.3.6.4.

Disruption mitigation schemes for ITER

2 pages

D.Whyte, M.Sugihara

3.3.7 Summary

2 pages
O.Gruber, M.Sugihara, R.Granetz, Y.Kawano

References

3 pages

Page 4 of 6

Issue:2

CHAPTER 8
PLASMA OPERATION AND CONTROLTABLE OF CONTENTS
8. PLASMA OPERATION AND CONTROL
30 pages of A4 format (in IPB it was 73)
8.1.

INTRODUCTION
2 pages(Schemes and architecture for ITER plasma control, ITER Design Scenarios, organization ofthis chapter)
Y. Gribov, J.Lister, D.Humphreys

8.2. SURFACE AND WALL CONDITIONING
2-3 pages(This section will be written by the Topical Group on Scrape-off-layer and Divertor Physics)
8.2.1. Conditioning Methods in Present Tokamaks
8.2.2. Conditioning Methods in ITER

8.3. PLASMA INITIATION
8.3.1. Plasma Initiation in Present Tokamaks
2 pages(New results, e.g. EC assisted plasma initiation in low electrical field at JT-60U)
E. Lazarus, T.Fujii

8.3.2. Plasma Initiation in ITER

2 pagesY. Gribov, A.Portone

Page 5 of 6

Issue:2
8.4. PLASMA BASIC CONTROL
8.4.1. Magnetic Position and Configuration Control
8.4.1.1.

Magnetic control in present tokamaks
3 pages(New results, e.g. experiments of magnetic control at TCV and there simulations
with DINA, high triangularity control, shape identification methods.)

8.4.1.2.

Magnetic control in ITER

J.Lister, J.Ferron, W. Treutterer, K.Kurihara, F.Sartori

3 pagesY. Gribov, A.Portone, K.Kurihara, J. Lister

8.4.2. Plasma Performance Control
8.4.2.1.

Performance control in present tokamaks
3 pages(Control of ITB will be presented in Chapter˚6, control of ELMs will be presented
in Chapter˚4.)

8.4.2.2.

Performance and burn control in ITER

A.C. Sips, J.Ferron, D.Mazon, S.Ide, Joffrin

2 pages

M.Shimada

8.4.3.

Plasma control simulations in present tokamaks and ITER
(e.g. equilibrium, performance, analog to a flight simulator)

5 pages

J.Lister, Y.Gribov, D.Humphreys, A.Portone, W. Suttrop

8.5. SUMMARY

2-3 pages
J.Lister, Y.Gribov, T.Ozeki, D.Humphreys

References

3 pages

Page 6 of 6

Tokamak Physics Basis の執筆に関する議論
進行役 O.Gruber(IPP) の議事進行は巧かった• 上記、ITPA の課題を対象とした構成で章立てがされている• 概ね、各節は、多国間の研究者の共著による調整された点• 他の部分との重複、矛盾した結論を避ける• 議論のベースとなっている理論モデルが確立されたものかど うか議論の的となった
1st publication は避ける（ 例 3.2.1.3 での Porcelli の内部キンクモデル ）• RWM の補正コイルによる制御に関する提案に対しては議論百出（ 例 3.2.3.3 での側面補正コイルによる制御、磁気プローブの信号（ ノイズを含む）に基づく）• ITER の運転、制御に関しては、議論百出議論における注目点-1
疑問点• LHD はト カマク研究者にとって何なのか◦ LHD の研究者は、トカマク研究者に何をアッピールしようとしているのか◦ トカマク研究者は、非軸対称系も含めたトーラス系を念頭に置いているか• ト カマクの電流ホール領域を MHD で記述できる 集団運動 領域と考えて良いのか◦ 磁気面が、温度、密度の良いリファレンスではない◦ 磁気面が、粒子軌道の良いリファレンスではない◦

個別運動 領域ではないのか• 新古典テアリングモード（ NTM ）の理論モデルは確立しているのか◦ アジャスタブルパラメータの存在• 抵抗性壁モード（ RWM ）の理論モデルは確立しているのか◦ 定式化に現れるパラメータの定義の曖昧さ

議論における注目点-2
個人的感想• ト ーラス系の MHD 平衡
MHD 平衡の多様性（ト カマク電流ホール、LHD ゼロ回転変換、LHD ダブレット 配位）
3 次元系のコード が 2 次元系で使用され始めている（ VMEC2000 ）• ト ーラス系の理論モデル、コード
可能な限り、3 次元系をベースとして理論モデル、コード を作成する
多様な装置での同一テーマの比較研究
NTM,RWM 等の理論モデルを確立する• LHD 実験結果と理論の比較を理論モデルの検証、拡張へと利用する

物理サブクラスターの活動に関して
初日の夜、物理サブクラスターの活動に関して話し合いを持った。

• 様々な立場• ITER 研究支援に対する意識の違い• 問題意識を共有できるか
活動への準備• H16 年度の LHD 共同研究（ 研究会）へ申請「トロイダルプラズマの MHD 安定性に関連した諸問題」
代表：中島徳嘉• 申請が承認されれば 、物理サブクラスター活動のための研究会を開く• 大学、JAERI 、NIFS 間の連係が取れるかど うかがポイント• 大学、研究所の法人化の動きのなかで、共同研究の意味を考え直す