JET status and perspectives
Francesco Romanelli
EFDA Associate Leader for JET
EURATOM MEdC Association day
26 November 2009
F. Romanelli 1 (36)
EURATOM MEdC Association day
26 November 2009
• The JET programme is strongly focussed on
the consolidation of the ITER design choices
and the preparation of ITER operations.
ITER
pellet
JET
ITER-like Ion Cyclotron
antenna
F. Romanelli 2 (36)
High frequency
pellet injector
EURATOM MEdC Association day
ITER-like wall
project
26 November 2009
• Very good performance of
auxiliary heating systems
Number of JET pulses with PNBI  20 MW
250
213 216
Number of pulses
200
– Record NB power above
23MW
143
150
100
65
50
25
24
21
2
0
0
1994
1996
1998
0
0
0
10
0
0
2000
2002
2004
2006
2008
Year
10Gbytes
per shot
• 50 new diagnostics completed or
under completion (some of them
specific ITER developments)
F. Romanelli 3 (36)
EURATOM MEdC Association day
JET raw data
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusions
F. Romanelli 4 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusions
F. Romanelli 5 (36)
EURATOM MEdC Association day
26 November 2009
ELM characterization and control
Divertor material damage sets the limit on allowable ELM energy losses
ITER min.
requirement
W
Predicted ELM
size in ITER
CFC
ELMs must be controlled
maintaining good H-mode
confinement!
F. Romanelli 6 (36)
EURATOM MEdC Association day
26 November 2009
ELM and pedestal characterization at high
currents up to 3.8MA
JET can investigate ELM
and pedestal conditions
of direct ITER relevance
MA
MW
ITER domain
MJ
High-resolution
Thomson scattering
F. Romanelli 7 (36)
EURATOM MEdC Association day
26 November 2009
Type I ELM power loads on PFC
Pre-ELM separatrix
Heat flux (MW/m2)
Filaments
Δt = 0 µs
Δt = 85 µs
Δt = 170 µs
Δt = 255 µs
Δt = 340 µs
Δt = 425 µs
Quasi-toroidal
mode numbers
of ~ 4 to 12
consistent with
previous
observations on
AUG
Target coordinate (m)
Time resolved IR measurements of heat
loads on divertor target
• Model of ELM filament parallel energy loss (W. Fundamenski PPCF 2006) in good
agreement with measurements
• Fraction of ELM energy deposited on the main chamber tiles ranges from 10 – 5 %,
decreasing with relative ELM size
• Suggests that mitigated ELMs on ITER (1 MJ) not a problem for main chamber tiles
F. Romanelli 8 (36)
EURATOM MEdC Association day
26 November 2009
ELM mitigation with magnetic
perturbations
Magnetic perturbation
 Edge stochastic magnetic field
 edge pressure gradient kept below threshold
In-vessel coils in DIII-D and ITER
Ex vessel coils (error field
correction coils) in JET
Advantage: large toroidal mode
number spectrum of the perturbation .
Advantage: External Coils, more
relevant for reactor application.
Limitation: Internal coils, subject to
neutron radiation => reactor relevance?
Limitation: low toroidal mode
number spectrum of the perturbation
F. Romanelli 9 (36)
EURATOM MEdC Association day
26 November 2009
ELM mitigation with external magnetic perturbation
field in JET
Ip = 1.5 MA; Bt = 1.78 T; q95 ~ 4.0; dU ~ 0.45
#69564
•
ELM frequency increased form 30Hz to
120Hz and ELM energy loss reduced from
7% to below noise level (~2%). Reduction
in ELM peak heat fluxes and carbon
erosion
•
Electron density decreases (pump out)
•
Electron and ion temperatures increase
(core and edge)
•
Reduction in the thermal energy
confinement but no change compared to
H-mode scaling
Coil current
kAt
Density
Temperature
keV
Confinement normalised
to H-mode scaling
D emission
•
•
•
F. Romanelli 10 (36)
Wide range in q95 (4.8 – 3.0) with n = 1, 2
N up to ~2.9 (no locked mode excited by n=1 field)
Low collisionality: n*e~ 0.09
EURATOM MEdC Association day
26 November 2009
ELM pacing using the vertical stabilisation
controller
Effect of a kick
70427@16.5
Coil
voltage
D emission
Plasma
Energy
• Successful pacing of ELMs demonstrated
• ELM frequency increased by at least a factor of 5
• Plasma energy not affected by kicks
D emission
Plasma
energy
F. Romanelli 11 (36)
EURATOM MEdC Association day
26 November 2009
Highly radiative N seeded ELMy H-mode with
type III ELMs extended to IP=3.25MA
Strong D & N2 fuelling
Both divertor legs detached
• Radiated fraction~ 70%
• H98=0.82
• ne=1.2x1020 m-3 ≈ Greenwald
density
• Wdia=7.6MJ
• Small type III ELMs
• fELM~1kHz
• Zeff <1.4
Scenario extrapolates to
17MA Q=10 on ITER
F. Romanelli 12 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusion
F. Romanelli 13 (36)
EURATOM MEdC Association day
26 November 2009
Hybrid scenario with improved
confinement
Hybrid scenario in ITER requires up to 50% increase over the Hmode confinement
Broader
q-profiles
associated
with better
confinement
Energy Confinement time (s)
H98(y,2) = 1.5
DIII-D
(NTH<2.7)
JET
(NTH<2.2)
AUG
(NTH<3.2)
H98(y,2) = 1
H-mode confinement scaling (s)
Other factors affecting confinement include:
• rotation
• pedestal
F. Romanelli 14 (36)
EURATOM MEdC Association day
26 November 2009
Steady State scenario at q95~5
N goal attained: Scenario optimised and more PADD available
 best N (total & thermal) at BT > 2.6T in JET
• Significant progress towards ITER SS parameters
• Need more work to increase NI current and get higher H98(y,2)
N =3
(Smoothed values)
Sustained for ~1.5s
F. Romanelli 15 (36)
EURATOM MEdC Association day
Science meeting,
18/05/2009
26 November 2009
ITER scenarios studies
F. Romanelli 16 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusion
F. Romanelli 17 (36)
EURATOM MEdC Association day
26 November 2009
JET ICRF heating systems
Upper half
Up to ~8.5MW in ELMy H –modes:
•
•
•
ITER-Like antenna 
A2 antennas C & D 
A2 antennas A & B 
Internal conjugate-T
External conjugate-T
3dB couplers
ITER-Like antenna:
–Operation with high mutual coupling between straps:
•Achieved in L mode but generator control
issues when full antenna is used.
Lower half
–High power densities (at 38kV)
•~6MW/m2 in L-mode
•~4MW/m2 in H-mode (ILA upper half)
–Reliable operation up to 42kV
–New arc detection systems (SMAD)
Antenna Front
Science meeting, 01/06/2009
F. Romanelli 18 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusion
F. Romanelli 19 (36)
EURATOM MEdC Association day
26 November 2009
Toroidal field ripple studies in JET
• JET
JET results suggests dBT < 0.5% in ITER
required to achieve QDT=10 goal
& reduce uncertainty
on confinement extrapolation.
• 32 coils
 Intrinsic ripple dBT ~ 0.08% 1.3
• Separate control of odd/even 1.2
coils allows to control ripple
1.1
• Ripple scan in the range
dBT ~ 0.08%-1%
Confinement 1.0
and density scan normalizedtime
to 0.9
H-mode
• 2.6MA/2.2T
scaling
0.8
• Neutral Beams only
• Fast particle losses up to 20% 0.7
with ferritic insets
ITER
w/o ferritic insets
Ripple (%)
F. Romanelli 20 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusion
F. Romanelli 21 (36)
EURATOM MEdC Association day
26 November 2009
Material migration in JET
JET DTE1 campaign (1997)
JET MKII A
Observations from recent experiments
First wall
 Main chamber is primary erosion source
 Transport by SOL flows to inner divertor
inner
louvre
Divertor
 Inner divertor is a net deposition zone
Erosion/deposition determined by magnetic
• 6 out of 35g injected tritium retained
configuration (line-of sight), power loads at strike-
• Major part of retained tritium is co-
points (ELMs), and local surface conditions (layers)
deposited with carbon in remote areas
 Be re-erosion is low in comparison to C
of the inner divertor (louvre)
 Transport of C to remote areas
 Strike points sweeps enhance C migration
Brezinsek, PPCF 2008; Kreter, PRL 2008
These observations can explain the large C deposition and T retention in DTE1
F. Romanelli 22 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusion
F. Romanelli 23 (36)
EURATOM MEdC Association day
26 November 2009
• Existence of ITG
threshold verified
experimentally
• Ions very stiff in low
rotation plasmas
while less stiff in
high rotating
plasmas
Normalised ion heat flux at r/a=0.33
Ion heat transport studies
R/LTI
threshold
F. Romanelli 24 (36)
EURATOM MEdC Association day
26 November 2009
JET participation
2009 Campaigns C26-C27
22 Associations
–290 scientists
–72 ppy on-site
Portugal
10%
Romania
2%
Poland
4%
Netherlands
1%
Italy
18%
Spain
2%
Sweden
5%
Ireland
0%
Hungary
1%
Switzerland
1%
Greece
1%
UK
17%
Germany
16%
Austria
2%
Belgium
7%
Denmark
1%
Czech Republic
0%
F. Romanelli 25 (36)
Finland
4%
EURATOM MEdC Association day
France
7%
26 November 2009
MEdC C20-C27 participation
4 scientists (1.7ppy) under under Task Forces Diagnostics and MHD
Competencies of Diagnostic Coordinator, Lost Charged Particle Diagnostics,
Magnetics, Neutronics, Resistive Wall Modes, Scientific Coordinator
S/T Task under MEdC Scientific Coordination
D-1.5.2 Determination of neutron field characteristics for high performance discharges
(12 sessions with S2-2.3.3 Development of SS scenario at high betaN H98th~1.5)
Yield, fluence and energy distribution measurements with superheated fluid bubble detector
spectrometers, activation probes and the TOFOR time-of-flight neutron spectrometer
F. Romanelli 26 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008-2009
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
• Conclusion
F. Romanelli 27 (36)
EURATOM MEdC Association day
26 November 2009
Enhancement Programme 2 in the
procurement phase
ICRH horizontal private limiter
ITER
ITER-like wall
Neutral Beam Enhancement
Plasma Control Upgrade
High-Frequency
Pellet Injector
Diagnostics
W coating at MEdC
JET
Bulk tungsten tile
F. Romanelli 28 (36)
Extended Octant 1 boom
EURATOM MEdC Association day
26 November 2009
Tungsten coating of CFC tiles at MEdC
New chamber( NDC) - 2008
6 magnetrons running
CFC sample from NDC
Good results from GLADIS
Coating tested at
GLADIS up to 16.5MW
F. Romanelli 29 (36)
EURATOM MEdC Association day
26 November 2009
Aim of the Tasks involving the coatings
Determine erosion of W in JET divertor tiles
W
Mo
using Ion Beam Analysis (4Mev Protons)
• Marker stripe on lamellas of tile 5: Bulk W
• Marker stripe on tiles 6, 7, 8:
Bulk W
W-layer (14 µm PVD or 30 µm PVD) on CFC
Use marker layer of 5 µm W and 7 µm Mo
Plasma
exposure
Samples prepared by C. Ruset (MedC) JW8-FT-3.41
W
Mo
W
Mo
Be
W
Mo
Bulk W
Bulk W
bulk
W
Erosion
F. Romanelli 30 (36)
EURATOM MEdC Association day
Deposition
26 November 2009
Coatings for the ITER-like Wall
• (8 µm) Beryllium coatings on Inconel are to be use in
some locations in the main vacuum chamber:
−
Max. heat load 0.5 MW/m2 in 20 s  10 MJ/m2
Original surface
5 mm
Tested: 1.8 MW/m2, 11 s
5 mm
• Beryllium erosion markers
have also been developed
with the goal of measuring
erosion < 10 µm
Be layer
Metal interlayer
Beryllium Tile
(C. Lungu, MEdC)
F. Romanelli 31 (36)
EURATOM MEdC Association day
26 November 2009
Tritium Depth Profiles on JET tiles using
AMS
Accelerator Mass Spectrometry (AMS) is a highly sensitive analyzing method,
having the big advantage, to measure very low tritium (T) concentrations
(<106Bq/g). In this regard, AMS is used in support to the particle transport studies
at JET.
JW9-FT-3.50 (G. Dinescu) and JW10-FT-3.60 (C. Stan-Sion)
Input:
Primary beam - Cs+ 15 J
Output:
Secondary beam -negative
neutral particles – 0,011 J
NEC-i MCSNICS ion source
F. Romanelli 32 (36)
and
(C. Stan-Sion, MEdC)
EURATOM MEdC Association day
26 November 2009
EP2-GRC: Upgrade of Gamma Ray
Cameras: Neutron Attenuators
Main objectives:
• Providing neutron attenuators for the
two subsystems of the KN3 gammaray imaging diagnostics:
a) KN3 gamma-ray horizontal camera
b) KN3 gamma-ray vertical camera
This diagnostics upgrade should:
• Make possible gamma-ray imaging
measurements in high power
deuterium JET pulses, and eventually
in D-T discharges.
Neutron
attenuator
Material
Neutron energy
2.45
MeV
14.1
MeV
Horizontal
H2O
102
15
Vertical
(Long
version)
H2O
104
102
Vertical
(Short
version)
H2O
102
15
Approximate attenuation factors attainable
within the project constraints
F. Romanelli 33 (36)
EURATOM MEdC Association day
26 November 2009
EP2-TCS: Tandem Collimators for Gamma
Ray Spectroscopy
Main objectives:
• To provide two neutron/gamma collimators for the Tangential Gamma-Ray
Spectrometer KM6T
This diagnostic upgrade should:
• Regain the capability of the KM6T system for fast particle physics studies of JET
plasmas
• Provide necessary conditions for the operation of the KM6T diagnostics in high
performance deuterium and deuterium - tritium JET discharges
F. Romanelli 34 (36)
EURATOM MEdC Association day
26 November 2009
OUTLINE
• Main JET results in 2008
–
–
–
–
–
–
ELM characterization and mitigation
Development of ITER scenarios
Test of the ITER-like Antenna
Effect of TF ripple on H-mode plasmas
Preparation of the ITER-like Wall experiment
Stability and transport studies
• Long term JET programme
– Status of the EP2 Programme
– JET beyond EP2
F. Romanelli 35 (36)
EURATOM MEdC Association day
26 November 2009
Next 10 years schedule
Original investment in and subsequent
upgrades of the JET Facilities (M€ of year)
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Construction
ITER
Construction
EVEDA
IFMIF
During the next few years JET will
be the only device of its class in the world.
JET will be the best machine to prepare the ITER
joint exploitation.
DT
experiment
Shutdown
JET
JT60SA
EP2 exploitation
ITER preparation
Commissioning and
Joint experiments
Other supporting activities (physics and technology)
Construction
100M€
F. Romanelli 36 (36)
EURATOM MEdC Association day
26 November 2009