overview of jet results

Overview of JET results

J.Pamela et al. 20th IAEA Fusion Energy Conference1-6 November 2004 Vilamoura, Portugal

46 Laboratories WorldwideSpecial thanks to Task Force Leaders and Operator (UKAEA)

Acknowledging all contributors to the programme

EFDA Parties

International Collaborations

JET’s contribution in preparation of ITER

I- Optimising Fusion Performance

II- Preparing for Long Pulse Operation

III- Optimising wall and divertor conditions (power deposition in steady and transient conditions )

IV- Controlling plasma in Real Time

V- Preparing for Burning Plasma Experiments

Trace Tritium Experiment overview by D.Stork (OV/4-1 Tuesday)

-scaling of confinement could be more favourable than IPB98(y,2) (joint JET/DIII-D experiment)

Further experiments with more heating required to reduce uncertainty and study limit

I- Optimising Fusion Performance

IPB98(y,2)

Pro

jec

ted

pla

sma

pe

rfo

rma

nce

Q ~

E B

2

D.McDonald EX 6-6

* & * kept constant

Density profiles are peaked in H-mode at low collisionality

=> could lead to higher fusion power in ITER

Confirmation of extrapolation to ITER requires further experiments : - dominant electron heating- extension to (high N, low *)

I- Optimising Fusion Performance

H.Weisen A.Zabolotsky EX/P6-31

Den

sit y

Pea

king

Collisionality

Peaking at low * independent of Prf/Ptot (and of li)

Confirmation of AUG results

High density Internal Transport Barriers with Pellet fueling

SIGNIFICANT PROGRESS TOWARDS ITER RELEVANT CONDITIONS

ne(0) ~ 0.7 x 1020 m-3 (~ nGreenwald)

Te ~ Ti

Low toroidal rotation ( 4 times smaller than in standard ITB's)

I- Optimising Fusion Performance

A.Tuccillo, EX1-1D. Frigione, C. Challis, M. de Baar, EPS 2003

ITB(r/a~0.4)

BT= 3.2T IP= 2 MA PLH = 1.9 MW PNBI = 8.6 MW PICRH = 6.6 MW

ICRH: Proof of Principle of ELM Resilience with (External) Conjugate T Antenna Scheme

module ‘A’ - conventional matching

module ‘B’ - conventional matching

module ‘D’ - conventional matching

amplifier ‘C’ - conjugate-T matching

Higher average power, lesser strain on generators

I.Monakhov, SOFT 2004 J-M.Noterdaeme SOFT 2004

ELMy Plasma

I- Optimising Fusion Performance

D

Advanced scenarios with ITBs: progress towards ITER Steady State scenarios

V loop close to 0

for 20 seconds

~1.6 MA mostly current driven by heating systems and bootstrap current

Record injected energy for JET : 326 MJ

(Full CD also obtained in other pulses, 1.8MA during 6-7 s periods)

II- Preparing for Long Pulse Operation

A.Tuccillo, EX1-1V.Pericoli, EPS2003

E. Joffrin, G. Sips EX/4-2 C. Gormezano EPS2004

(AUG & DIII-D fromITPA database)

X 10 -3

N

*

1.7 T

For q95 ~4

AUG

JET

.T

ITER

3.4T

3.1T

DIII-D

AUG and DIII-D

1 3 5 7 90

1

2

3

Confirmation of "hybrid" scenarios on JETII- Preparing for Long Pulse Operation

Scenario confirmed for the 1st time with dominant RF- heating

Asdex-U “Improved H-mode” confirmed in JET identity experiments

Explored on JET at lower (* ,*) Power limited yet (not -limited)

LHCD: ITER-relevant large distance coupling

J.Mailloux EX/P4-28 A. Ekedahl, EPS 2004

Together with the successful test of the PAM coupler on FTU: important milestone achieved for LHCD towards ITER

3MW LHCD coupled

at 10-11cm distance between LCFS and launcher

with D2 injection (81021el/s) near the coupler

in ELMy plasma

II- Preparing for Long Pulse Operation

III- Optimising Wall and Divertor Conditions

Radiation in Divertor (bolometry)

Before ELM After 1 MJoule type-I ELM

Divertor target ablationmust be avoided

The quest for mild ELM regimes

•Mixed Type-I-Type-II at ne~nG >0.4 up to 3MAencouraging, but Type-I ELMs still there... (Stober, EX/P1-4 and Sartori EX/6.3)

• N2 seeded high radiation type-III ELMy H-mode 2.5MA (see later)

At lower current (further from ITER * and *): (Stober, EX/P1-4)

- No controlled EDA modes found on JET (Alcator C-mod shape, 0.65MA) - Type II ELM phases “à la AUG” found at ~0.9 MA - grassy ELMy H-mode obtained under restrictive conditions (see later)

=> unfavourable * (or *) dependence for EDA and type II ? => strong edge shear needed ?

ELM MITIGATION REMAINS TOP PRIORITY Impurity seeding / Edge ergodisation, see DIII-D / Pellet ELM-pacing, see AUG

+ MORE MODELLING EFFORTS and ELMs PHYSICS

III- Optimising Wall and Divertor Conditions

J. Stober EX/P1-4G. Saibene EPS2004

The quest for mild ELM regimes (ctd)III- Optimising Wall and Divertor Conditions

p in

crea

ses

Grassy ELMs (similar to JT60-U)low Ip~1.2MA, q95~6-7, QDN, p1.6

so far quite restrictive conditions / further exploration needed

Type III ELMy H-mode with N2 seeding

III- Optimising Wall and Divertor Conditions

confinement degradation could be a price to pay to achieve very mild

edge conditions (radiation up to 95%) => this scenario could extrapolate to ITER (Q=10 at 17MA) => scaling needs to be determined

The quest for mild ELM regimes (ctd)

J.Rapp et al.

NF44 (2004)312

ITER Q=10 17MA JET #59029Ip 17MA 2.5MABt 5.3T 2.0TH98 0.75 0.73fGDL 1.0 1.05

N 1.5 1.7q95 2.6 2.6Ti/Te 1.1 1.2 0.5 0.44frad 0.75 0.8Zeff 1.7 2.2WELM/Wtot

1% 0.7%

Energy balance in a wide range of disruption typesIII- Optimising Wall and Divertor Conditions

• Only a fraction of Wthermal measured into the divertor (similar results with large ELMs power deposition)

=> ITER divertor specifications wrt transients might be relaxed => Consequences for ITER first wall to be assessed

Plasma Thermal Energy

Energy in Divertor (IR)

A.Loarte IT/P3-34 V.Riccardo, submitted to PPCF and NF

Real Time Control of the Plasma Shape with the Extreme Shape Controller (XSC)

Plasma shape kept constant even in the presence of large variations of p and li

=> safe operation of highly shaped ITER-like configurations

IV- Controlling the Plasma in Real Time

F.Sartori, Albanese, De Tommasi/UKAEA, Ambrosini/ENEA, SOFT 2004

JET #61995

First simultaneous control of q-profile and ITB strength

IV- Controlling the Plasma in Real Time

• 3T/1.7MA H89x N ~ 3.4D.Moreau EX/P2-5, T.Tala TH/P2-9A.Tuccillo EX/1-1

q profile control

<- 7 seconds ->

*Te control

V- Preparing for Burning Plasma Experiments

Tomography constrained by plasma equilibrium

A.Murari OV/P4-9, S.Sharapov EX/5-2a; V.Kiptili et al., PRL submitted

fast D ions fast alphas

Constrained by magnetic equilibrium

Progress towards ITER Burning Plasma diagnostics Fast particle -Tomography

Application on ITER requires efficient neutron shielding (on-going work with Russian Federation)

ICRF beatwave

TAE antenna

Alfvén CascadesTypical edge magnetics spectrogram showing Alfvén cascades

together ICRF beatwaves and TAE antenna sweeping:

Alfvén cascades

Shot

V- Preparing for Burning Plasma Experiments

Key tool for fast particle studies, in particular in advanced modes

Many more harmonics observed

Reflectometer in interferometric mode reveals unprecedented cascade evolution details showing modes up to n=16:

Sharapov et al PRL93 (2004) 165001

see also R.Nazikian EX / 5-1

‘Monster’ sawtooth control

Essential technique for ITER to control fast alphas stabilised sawteeth

V- Preparing for Burning Plasma Experiments

#58934

R.Buttery, EX/7-1LG.Eriksson et al PRL92 (2004)235004

core +90º phasing ICRH to make fast particles and large sawteeth (period up to 0.4s)

q=1 -90º phasing ICRH for current drive sawtooth destabilisation

Summary of ELMy H-Mode Development

ITER (Q=10, Ip=17 MA, inductive) : =0.49 q95=2.6 fGW= 1 H=0.75 N=1.5 WELM/WTOT= 1% Prad/PTOT=75%

Type III ELMs, N2 seeding (new development)

Type I ELMs

ITER (Q=10, Ip= 15 MA, inductive): =0.49 q95= 3 fGW= 0.85 H=1 N=1.8

* * simultaneously achievable on JET (50MW at 5MA)

Summary of advanced modes development

ITER (PPA Q=5.4, Tburn=1000s): = 0.48 q95=3.5 fGW=0.85 H=1 N=1.9 fBS=17%

Hybrid Mode or improved H-mode (new on JET)

ITER (Q=5 Steady State): =0.49 q95=5.5 fGW=0.8 H=1.5 N=3 fBS=50%

Plasmas with ITBs

Nota Bene: much milder requirements used in the normalisation for Hybrid Mode

* * simultaneously achievable on JET (50MW at 5MA)

In red, same normalisation as ITB mode

Conclusion: progress towards ITER • High confidence in ELMy H-mode performance for ITER (Q=10 reference)

• More favourableN scaling and density peaking at low collisionality Likely to increase margins for high fusion performance on ITER

• ITER-relevant ICRH (conjugate T) and LHCD coupling (large distance) • Real Time Control Demonstrations (highly shape plasmas; j(r) and T(r) profiles in ITB plasmas)

• Advances in Burning Plasma Diagnostics (fast particles -tomography, Alfvèn cascades, neutrons)

Support to defining ITER auxiliaries progressing well

• ITB Plasmas extended towards high performance, high density, long pulses• Hybrid modes confirmed on JET and extended towards ITER conditions

Long Pulse modes and their control progressing well / scaling to be determined

• steady mild ELM regimes achieved with loss of confinement (N2 seeded Type III) or in restrictive conditions (grassy ELMs)

Encouraging results on mild ELMs / Mitigation of ELMs remains top priority

• Lower power fraction than foreseen in Divertor during transients (disruptions,

ELMs) ITER Divertor and First Wall specifications may need revision

• Erosion, SOL flows and deposition studies (results not shown, see PSI 2004) Favourable for T-retention / Be wall lifetime to be assessed

Tuesday 2 NovemberOV4/1 Derek STORK Overview of Transport, Fast Particle and Heating and Current Drive Physics using Tritium in JET plasmasEX1/1 Angelo TUCCILLO Development on JET of Advanced Tokamak operations for ITEREX1/4 Wolfgang SUTTROP Studies of the "Quiescent H-mode" regime in ASDEX Upgrade and JETEX2/4-Ra Wojczek FUNDAMENSKI Power Exhaust on JET: an Overview of Dedicated ExperimentsFT1/3 Richard GOULDING Results and Implications of the JET ITER-Like ICRF Antenna High Power Prototype Tests

Wednesday 3 NovemberTH2/1 Yueqiang Liu Feedback and Rotational Stabilization of Resistive Wall Modes in ITEREX4/2 Emmanuel JOFFRIN The "hybrid" scenario in JET: towards its validation for ITERIT1/2 Gabriella SAIBENE Dimensionless identity experiments in JT-60U and JET

Thursday 4 NovemberEX5/1 Raffi NAZIKIAN Energetic Particle Driven Modes in Advanced Tokamak Regimes on JET, DIII-D, Alcator C-MOD and TFTREX5/2-Ra Sergei SHARAPOV Experimental studies of instabilities and confinement of energetic particles on JET and on MAST EX6/3 Roberta SARTORI Scaling Study of ELMy H-Mode Global and Pedestal Confinement at high triangularity in JETEX6/6 Darren McDONALD Particle and Energy Transport in Dedicated *, and * Scans in JET ELMy H-modesTH5/3 F NABAIS Cross-machine NTM physics studies and implications for ITEREX5/1 Richard BUTTERY Cross-machine NTM physics studies and implications for ITER

Saturday 6 NovemberEX10/1 Volker PHILIPPS Overview of recent work on material erosion, migration and long-term fuel retention in the EU-fusion programme and conclusions for ITER

ORAL PRESENTATIONS reporting JET related results

OV/P4-9 A.Murari ·New developments in JET Neutron, Alpha Particle and Fuel Mixture Diagnostics with potential relevance to ITER

EX/P1-2 P.Monier-Garbet Impurity-seeded ELMy H-modes in JET, with high density and sustainable heat loadEX/P1-3 E.Solano ELMs, strike point jumps and SOL currentsEX/P1-4 J.Stober Small ELM regimes with good confinement on JET and comparison to those on ASDEX Upgrade,

Alcator C-mod, and JT-60UEX/P2-1 F.Crisanti JET RF dominated scenarios and Ion ITB experiments with no external momentum inputEX/P2-5 D.Moreau Development of Integrated Real-Time Control of Internal Transport Barriers in Advanced Operation

Scenarios on JET.EX/P2-22 T.Hender Resistive Wall Mode Studies in JETEX/P2-27 V.Plyusnin Study of runaway electron generation process during major disruptions in JETEX/P3-11 F.Rimini Development of Internal Transport Barrier scenarios at ITER-relevant high triangularity in JETEX/P4-5 B.Gonçalves On the momentum re-distribution via turbulence in fusion plasmas: experiments in JET and TJ-IIEX/P4-26 P.Lamalle Expanding the operating space of ICRF on JET with a view to ITER EX/P4-28 J.Mailloux ITER Relevant Coupling of Lower Hybrid Waves in JETEX/P4-45 D.Testa Experimental Studies of Alfven Mode Stability in the JET TokamakEX/P5-22 T.Loarer Overview of gas balance in plasma fusion devicesEX/P6-18 P.Mantica Progress in understanding heat transport at JETEX/P6-31 H.Weisen Anomalous particle and impurity transport in JETTH/P2-9 T.Tala Progress in Transport Modelling of Internal Transport Barrier and Hybrid Scenario Plasmas in JETTH/P4-49 V.Yavorskij Confinement of Charged Fusion Products in Reversed Shear Tokamak PlasmaTH/5-2Rb K.Gorelenkov Fast ion effects on fishbones and n=1 kinks in JET simulated by a nonperturbative NOVA-KN codeTH/P5-18 D.Coster Integrated modelling of material migration and target plate power handling at JETIT/P3-32 G.Cordey The scaling of confinement in ITER with and collisionalityIT/P3-34 A.Loarte Expected energy fluxes onto ITER Plasma Facing Components

during disruption thermal quenches from multi-machine data comparisons

POSTER Contributions with JET related results

RESERVE TRANSPARANCIES

165 days of experimentation on JET since October 2002 of which:- 10 days with reversed plasma Ip and Bt (BxB upwards) - 20 days in H and He plasmas - 20 days Trace Tritium Experiment / 3rd operation in Tritium on JET / overview by D.Stork (OV/4-1 Tuesday morning)

MkII-SRP divertor since 2002(septum removed):- comparison septum/no septum- access to high ITER-like

From 2005: MkII-HD (high - 40 MW capability- ITER-like at 3.5 - 4 MA

Trace Tritium Experiment (Oct. 2003) 14 MeV D-T neutron tomography provides time and spatial

evolution of T distribution => Particle Transport studies, see D.Stork Tuesday OV/4-1

A.Murari OV/P4-9L.Bertalot/S.Popovichev EPS 2004

V- Preparing for Burning Plasma Experiments

• Handle up to MW power for s with strike point sweeping• More flexibility for ITER matched triangularity plasmas (U~., L~.)• Refurbishment of divertor diagnostics•Operation in

Power Handling with ITER-like plasma shapes: modified divertor (MkII-HD) under installation

ITER shape High Plasma

High Field Side Gap Closure tiles : protect divertor diagnostic cables

Load Bearing Septum Replacement tiles : Increase power handling

ICRF System

A

B

C

D

dB couplers

JET-EP

External conjugate T

/

/.

/

/.

Reliable Power into H/L

Internal conjugate T

-spectroscopy tomography of fast - distribution

Kiptily, UKAEA

Tomography constrained

by plasma equilibrium particle density measured by emission in agreement with simulationadaptable for DT experiments using Li filters (collaboration with Russian Federation)

1 2 3 4 5 6 7 80

100

200

300

400

500

600

700 110 & 70 keV 4He-beam

70 keV 4He-beam

9Be( 4He,n) 12CE=4.44 MeV

12C(D,p)13

CE=3.1 MeV

Co

un

ts

Gamma-ray, energy, MeV

58.0 58.2 58.4 58.6 58.8 59.0

1.5x103

2.0x103

2.5x103

3.0x103

ICRF notch

= 0.30(3) s

4.4

4-M

eV -

em

issi

on

inte

nsi

ty

t ime, s’s from Be- reactions (E > . MeV)

slowing down directly measured

Behaviour well understood: successfully reproduced by Transport codes

First direct measurements of -particle slowing down with spectroscopy (Feb. )

Simulation of fusion ’s by ICRH acceleration of injected He particles

Kiptily/UKAEA

V- Preparing for Burning Plasma Experiments

ICRF beatwave

TAE antenna

Unprecedented details of evolution of Alfvèn cascades using relectometer

• Modes visible up to n=– world record resolution!

Typical edge magnetics spectrogram showing Alfvén cascades together ICRF beatwaves and TAE antenna sweeping:

Many more harmonics observed

Reflectometer used in interferometer mode (Sept.) reveals unprecedented cascade evolution in much higher detail than ever before

Alfvén cascades

Shot

Pinches/IPP-Garching, Buttery/UKAEA, PPPL

low with high (): scaling of E

. / . MAin C

ITER value confirmedat highest Ip = . MAand q=

High gas-fuelling with PINIs not possible,maybe PINIs at . MA. More ICRHwill be helpful in .

No time for increaseof q at . MA

Symbols: . MA dataat different q . MA

in C/C

R. Sartori, P. Lomas: IAEA

-0.2

0

0.2

0.4

0.6

0.8

-10 0 10 20 30 40 50

Distance from Separatrix (Mid-plane mm)

Ma

ch

Nu

mb

er

Normal Field 1.90 T Reverse Field 1.90 T

Normal Field 1.78 T Reverse Field 1.75 T

Normal Field 1.64 T Reverse Field 1.54 T

Shot: 56723, 59737 Ohmic

Scans in:

• q -.

• Pin

• ne

• He vs D & CD puffs

Symmetric component

• Classical drifts

Offset in flow

• Ionisation driven

• Ballooning transport

• Turbulence driven

• ……..?

Inner divertor

Mach No.

Topic : SOL and divertor physicsC - reversed B allowed study of SOL flow E..

Erents, Pitts

RWM studies confirm damping modelExplore ‘error field amplification’ effects, which brake plasma rotation allowing wall mode growth...

• Clear response seen:

T A S K F O R C E M

Response rises as no-wall limit is crossed

.li

NBI /MW

Applied field /a.u.

Plasma response /a.u.

N

Time (s)

• Well described by modelling:

• Validates kinetic damping model– to allow prediction of rotational stabilisation thresholds for ITER

with-wall limit

MARS prediction: • Kinetic

damping model

• No free parameters!

I- Optimising Fusion Performance

T+ fuel ion transport in Advanced ModesDiffusion coefficient approached neoclassical value at Internal Transport Barrier

TURBULENCE SUPPRESSED at Internal Transport Barriers

K-D.Zastrow,D.Stork/UKAEA

TransportBarrier

Gyro-Bohm scaling confirmed

up to */*ITER~

Scaling law: cE ., but overall trend of JET data (grey dots)

falls at low

=> New scans at fixed conducted / consistent with cE .

overall trend in JET Data Base could be due to correlation

I- Optimising Fusion Performance

0

0.2

0.4

0.6

0.8

1

1.2

1.4

100 150 200 250 300 350 4001/* = a/i

HIP

B98

(y,2

)

SSDB

Type I

Type III

4 MA

4.3 MA

G. Cordey: EPS , D. McDonald: H-mode TCM , IAEA

. - . MA, q=.

MeV Neutron tomographyStudies of tritium transport

Excellent capability to predict T+ transport confirmed by MeV D-T neutrons tomography (Oct. )

Tomography constrained by plasma

equilibrium Bertalot, Angelone/ENEA, this conferencePopovichev/UKAEA

V- Preparing for Burning Plasma Experiments

Studies of transient power load to the wall: Improved diagnosis of MJ Edge Localised Modes

• Stored energy: W R

• Radiation increases non-linearly with ELM size

PRad

MW

Wstored MJ

MJ

PNBI

(MW)

Wdia = MJ ELMs achievable on JET allow study of extreme transient power load conditions

High radiation likely due to target ablation

Before ELM After ELM

III- Optimising Wall and Divertor Conditions

0.0 0.2 0.4 0.6 0.8 1.0

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8 2.25 - 3.4 T, 2.0 - 3.0 MA 3.2 T, 1.0 MA 3.2 T, 2.0 MA, current hole profile 3.2 T, 3.0 MA, current hole profile

, s

(m

easu

red

)

se

, s (calculated)

First direct measurements of slowing down Comparison of the .-MeV- decay time and

calculated slowing-down time

Plasmas with Current Hole show degraded

confinement / agrees

with simulation

-MA Shots with ITB and

Cburrent Hole

V.Kiptili PRL and EPS

V- Preparing for Burning Plasma Experiments

-MA Shots without Current

Hole

Erosion and co-deposition normal and reversed BxB operation provide a

consistent picture

10

100

1000

59400 59600 59800 60000 60200 60400

pulse number

oute

r T ri

se / p

ower

(deg

C/MW

)

IR anomaly disappears over ~ pulses

C Rev B

C restart

L.Pickworth, P.Andrew

III- Optimising Wall and Divertor Conditions

Matthews, LikonenSpectroscopy and Surface analysis confirm deposition in inner divertor during normal BxB operation