W Morris, Objective 2. Roadmap Workshop, Garching 13-14 April 2011 1 Roadmap Objective 2 “Secure...

W Morris, Objective 2. Roadmap Workshop, Garching 13-14 April 2011 1

Roadmap Objective 2

“Secure ITER Operation”

Initial report

Roadmap workshop, Garching, 13-14 April 2011

Göran Ericsson

William Morris (rapporteur)

Jef Ongena

Hartmut Zohm


ContentsGuidelines – Hasinger report

Aim of our work, approach adopted,

Assumptions, time frame and context

Scope – what's in, what’s out

Scenarios – which ones

Modelling and theory – aims

Examples of risk/impact-based analysis to guide key EU activities

Facilities – existing and proposed (lists)

Conclusions


Guidelines – Hasinger reportObjective 2 - Secure ITER Operation: by expanding the knowledge

base to maximise the scientific output of ITER. Develop operational scenarios that will secure and even exceed the baseline performance. Ensure the rapid and efficient start up of ITER operation, and protect the investment in ITER by minimising the chances of unexpected technical problems that would delay exploitation or incur extra cost.

Deliverables: In the next decade the programme must deliver:

a) Several robust, low risk, high performance operating scenarios for ITER that meet and in some cases exceed baseline requirements. At least some scenarios should be capable of long pulse operation, allowing an extrapolation to DEMO.

b) The capability and tools for accurate predictive modelling of ITER performance. These tools must integrate models of confinement, stability, energetic particle physics and wall interaction. Their validation should be prime programmatic objectives of the accompanying facilities.

c) Any satellite facilities that are necessary to support ITER operations.


Short version…Break down scenarios into the known problem areas (Associations, ITPA, Facilities Review, ITER research plan etc)

Think what we can do which can genuinely be applied on ITER plasmas to reduce risks and/or make them better (“think like ITER”)

• identifiable output (i.e. we know when we’ve done it)

Identify which Associations interested, facilities available

This can be basis of a roadmap rooted in a practical programme

Some summary info from the input

Now for some details…


Aim of our work - IIt is absolutely essential that ITER succeeds, and that high performance is achieved as quickly as possible.

Much operation time can be saved on ITER with good preparation of the physics understanding, modelling tools and, especially, the scientists. Conversely it could go very slowly.

ITER may perform above its baseline goals – this will need knowledge, inventiveness and possibly some enhancements

The complexity of tokamaks and the physics requires a very able and motivated community

We need to work out the best way to prepare for this – FP8 is key

We need to provide the basis for a vigorous, lively, innovative programme where it is clear why it has to be a certain size.


Aim of our work - IITokamak performance depends on the plasma scenario

Scenarios consist of many elements and their integration.

Almost all aspects will be different on ITER, to some extent

Address elements and integration capabilities and programme

Try to establish high level targets that

• will visibly help ITER

• we know when we’ve hit

• are readily linked to the working-level programme

Not defining programme, but collecting ideas on topics and approaches


Input (for today and later)Ideas and capabilities from the Associations (the spreadsheets) - >1000 entries for objective 2 (only a subset in this talk)

ITER Research Plan (v2.2, 2FB8AC)

Facilities Review report and milestones (not the input documents)

ITPA research needs

STAC knowledge

This workshop


AssumptionsEU should develop the capability to implement the scenario effectively on ITER, in all its aspects, without relying on input from other ITER parties

EU should develop independent modelling capability

Funding is available for “reasonable” enhancements to existing facilities (experimental and computational)

JT-60SA and the IFERC HPC are assumed to be EU facilities


Scope – what’s in• All scientific activities to develop end-to-end scenarios

• All activities to develop models (basic theory, codes, computers)

• Enhancements to existing facilities, experimental or computational

• Assessment of the need for and capability of enhancements to ITER, JT-60SA, IFERC computer

Scope – what’s out

• Operation of the plant at a technical level (diagnostics, tokamak systems, H&CD systems)

• Maintenance, remote handling

• Implementation of enhancements to ITER or BA facilities

• Engineering modelling of ITER components


Scenarios“Deliverables: In the next decade the programme must deliver:

a) Several robust, low risk, high performance operating scenarios for ITER that meet and in some cases exceed baseline requirements. At least some scenarios should be capable of long pulse operation, allowing an extrapolation to DEMO.”

What is a scenario?

How do we know they are robust and low risk?


What is a scenario?Final state (flat top, integration in space):

• current, field, plasma shape, density, temperature, etc

• fraction of non-inductive current drive

• nature of transport, transport barriers, stability and stability margins

• consistent heating, current drive and fuelling

• divertor solution

End-to end integration in time

• vessel preparation

• breakdown, start-up, ramp-up and transition to flat top

• Control: optimisation, transients (external and plasma-induced)

• termination, ramp down

ITER needs different scenarios for high Q, long pulse steady state.


Scenarios – which ones?Low activation phase – not addressed directly today, but must be part of programme

• Hydrogen plasmas and attempts at H-mode

• Helium H-modes

“Q=10” (DD as well as DT)

• ELMy H-mode

• Improved H-mode / Hybrid / Advanced Inductive mode

Steady state/long pulse

• Hybrid/Advanced Inductive mode

• Advanced tokamak – non-inductive


Scenarios: what does delivery mean?Experience shows

• scenarios cannot be simply transported (took several years to translate hybrid successfully from ASDEX Upgrade to JET)

• a written recipe is completely inadequate

• a combination of experienced people, good data, and good theory-based models is needed

• ITER must have the measurements and actuators to optimise

• Delivery is only secure when the scenario has been run on ITER

Considerations

• What can we actually do that will make a significant difference?

• How do we demonstrate/quantify this? (imagine we are running ITER)


Scenarios: what does delivery mean?Possible (theoretical) example:

The edge pedestal height is critical to ITER’s performance in ELMy H-mode

We can estimate height, but our goal should be evidence that we can control and improve it. E.g:

• Experiments where something is changed and the pedestal gets wider and higher

• Theory-based, experimentally tested models to explain why it happened

• modelled techniques that would have the same effect on ITER.

ITER Physics Basis, 2007.

Nucl. Fusion 47 S18


Predictive capability? “Deliverables: In the next decade the programme must deliver:

b) The capability and tools for accurate predictive modelling of ITER performance. These tools must integrate models of confinement, stability, energetic particle physics and wall interaction. Their validation should be prime programmatic objectives of the accompanying facilities.”

Models allow us

• to bridge gap from present devices, design ITER plasmas in advance

• to fix/optimise ITER plasmas: there will be great pressure on run-time

Theory allows us

• To base our models on best physics understanding

• Use the models outside their range of experimental validation

We should aim for first principles physics, not purely empirical models

This talk: specifics under the “scenario” topics, infrastructure under ITM


Satellite facilities“Deliverables: In the next decade the programme must deliver:

c) Any satellite facilities that are necessary to support ITER operations.”

These are facilities that operate alongside ITER addressing issues that arise during the operation (which cannot be answered adequately by ITER and its team). Also prepare enhancements

JT-60SA is assumed to be operational towards the end of the period FP8, FP8+2, and is aimed towards DEMO as well as ITER

Other major satellite facilities would be justified by their input in parallel to ITER


Satellite facilitiesAt present (April 2011) we do not have ideas from Associations on

• the programme in parallel with ITER,

• the exploitation of the satellite facilities proposed by Associations.

So, not easy to give views on necessary satellite facilities here.

But: issues raised here likely to apply during ITER operation, so we have an important step

Several Associations indicated they wish to contribute to a discussion on the definition of a possible EU satellite – this should start soon (using report of the earlier expert group on ITER & DEMO satellites?)

Substantial effort is indicated in the tables for FAST, upgrades of other facilities (AUG, TS, MAST and some other systems/facilities)


Approach adoptedIdentify ingredients of a scenario (e.g. core transport, pedestal height)

Include common activities such as H&CD, fuelling, diagnostics, control

Identify risks/uncertainties

Suggest mitigation actions (using Association and other ideas)

Identify what success means, what difference we will make. “how exactly will it make ITER better” (rather than only “improved understanding”)

Identify EU capability (use Association enhancement ideas if key to the mitigation)

Identify interested Associations from the input (will not be complete list)

Risks and activities are not ranked at this stage


Specific topicsOnly a subset here, to identify main capabilities.

Some ideas for clear impact on ITER. Will be other/better ideas. Principle is “if you were on ITER, what would you want and use?”

• Q=10 ELMy H-mode: pedestal (incl ELM mitigation), L-H, integration

• Q=10 Hybrid: core transport, self-regulation/control, integration,

• Q=5 advanced: ITB formation and control, integration

• Fuel retention

• Erosion/deposition

• Fast particle transport/losses

• Rotation generation and transport

• SOL and divertor

• ICRH coupling and compatibility

• Disruptions


Q=10 ELMy H-mode: H-mode accessComment/status

• Power in ITER marginal esp. in H, He phase.

Mitigation, and evidence of success

• More power on ITER, esp in H/He phase; Other triggers (flow changes, divertor leg, ion loss, pellet, current ramps); T early on ITER

• More power agreed. Demonstrated lower threshold based on first-principles theory

EU capability & Associations

• JET (esp if T); AUG; MAST; TCV; TJ-II (for understanding), COMPASS.

• Strong theory + well diagnosed machines

• CCFE, CIEMAT, CRPP, HELLAS, IPP, IPP.CR, ÖAW, TEKES

H – 3.8MW

D – 2.9MW

DT – 2.1MW

T – 1.7MW


Q=10 Hybrid: GeneralComment/status

• q(0)>1 – relies on benign instabilities; transfer slow (AUG JET)

Risk/uncertainty

• No self-regulation. Core confinement poor, or ITBs. Low pedestal if radiative divertor; metal accumulation; isotope effect


• Combined exps & theory → self-regulating transport and rotation, options for q(r)

• End-to-end transient-resilient scenario model


• JET, AUG, JT-60SA, MAST, TCV, TS

• CCFE, CEA, ENEA, IPP, CRPP? others?

Plasma pressure or temperature

Radius

Hybrid mode aims to have improved core confinement but without an internal transport barrier and its control needs


All scenarios: Erosion and redepositionComment/status

• Wall lifetime, retention, resilience to ELMs & disruptions, dust production, impurity influx all key.

Risk/uncertainty

• Unacceptable metal impurity influx. PFC material degrades. Dust production

Mitigation , and evidence of success

• Seeding/fuelling, higher density edge, ELM control, disruption avoidance

• Demonstration of prolonged JET ILW operation at high power. Understand why materials change, how dust can be reduced


• AUG, JET, TS, FTU, MAGNUM-PSI, TEXTOR; post-mortem analysis

• CCFE, CEA, ENEA, ENEA-CNR, FOM, FZJ, IPP, IPPLM, IPPLM, MHEST, TEKES, ULB, VR


All scenarios: Fuel retentionComment/status

• Critical for ITER operation – carbon data unacceptable, Be/W situation unknown.

Risk/uncertainty

• Even with metal wall retention may be too high, and effective removal techniques will be needed. Nature of retention (depth) may depend on scenario


• Experiments with metal wall – accountancy, wall conditioning to recover (ICWC?). Tritium allows greater accuracy.

• Demonstrated data on accuracy of accounting, quantified recovery techniques


• JET, AUG, TEXTOR, Magnum-PSI, Post mortem analysis facilities. Metal surface essential?

• FOM, FZJ, MHEST, TEKES, VR (assume others such as IPP, CEA, CCFE)


H&CD: ICRH couplingComment/status

• Physics of coupling quite well understood, but realisation unreliable. Impurity influx

Risk/uncertainty

• Coupling depends on unknown edge plasma, sensitive to scenario. Impurities


• Develop way to set density in front of antenna, for good coupling for all plasmas; tune phasing to reduce sheath effects

• Proven physics model to show density and sheath in front of antenna is controllable.


• JET, TEXTOR, AUG, FTU, Tore Supra. System changes may be needed

• CCFE, CEA, ENEA, IPP, ERM-KMS, VR.

ITER like Antenna

Lower Hybrid Launcher

LH and ICRH systems in JET

ICRH A2- Antenna


All scenarios: Fast particle transport/lossComment/status

• Critical for -heating effectiveness and profile, NBCD, sawtooth control

Risk/uncertainty

• Fast particle-driven modes cause unacceptable losses (damage, loss of -heating or NB current drive). Sawtooth control fails (and more NTMs result)


• Model improvements based on mixed data. Better diagnostics (confined & lost ions, mode structure, and TAE probes), varied fast ion populations, distribution.

• ITER’s drive and damping terms tested experimentally; ITER-applicable turbulence effects on fast ions tested. Estimates for ITER and ideas to reduce


• AUG, JET, MAST, TCV (NBI, TAE antenna upgrades), RFX (?, NBI upgrade)

• CCFE, CRPP, DCU, ENEA, ENEA-CNR, FOM, HAS, IPP, ÖAW, RFX, RISØ, TEKES, VR


All scenarios: DisruptionsComment/status

• Limit operation, generate dust, damage PFCs.

Risk/uncertainty

• Occurrence rate and impact; Predictions (e.g. neural nets) don’t transfer, too late in pulse


• Integrated avoidance strategy; theory & model of runaways, toroidal asymm, mitigation

• Transferred models of mitigation/prediction; integrated avoidance to fit ITER infrastructure


• JET; AUG; MAST, TS, FTU, TEXTOR, RFX(?)

• CCFE, CEA, CIEMAT, CRPP, ENEA-CNR, ENEA, FZJ, HAS, IPP, IPPLM, MHEST, RFX, VR

Analysis of root causes showing wide range, and thus potential benefit of integrated operational approach (JET)


“Infrastructure”Comment/status

• The programme needs a wide range of supporting capabilities: diagnostics, theory, modelling, control, computer facilities, data acquisition, data handling, operations

EU capability

• Wide capability on all systems. There will be some weaker areas.

Associations

• All Associations contribute. Some have made specific mention of key areas such as diagnostics, data acquisition and control, exascale computing. Some relate to specific experiments such as JET DT.


ITER enhancementsComment/status

• A range of enhancements during ITER’s life are likely. Diagnostics and LHCD are already in mind. Includes diagnostics of ancillary systems such as NBI source

• Not yet clear which parties would provide – may affect level of R&D outside F4E in EU

EU capability

• Wide experience on all tokamak systems. Future satellite facilities.

Associations

• Probably large majority – CEA (Obj 1), DCU, ENEA-CNR, ENEA, IPPLM, RISØ mention specifically.


Scenarios: summary of what is needed“Deliverables: In the next decade the programme must deliver:

a) Several robust, low risk, high performance operating scenarios for ITER that meet and in some cases exceed baseline requirements. At least some scenarios should be capable of long pulse operation, allowing an extrapolation to DEMO.”

Experimentally validated models for several key elements in order to design ITER scenarios and have demonstrated options to improve/correct

• e.g.: edge pedestal, transport in hybrid, L-H transition

Identification of issues for integration (in space and time) and proven approaches

Techniques for common issues such as fuel retention, ICRH coupling

A capable motivated team to transfer to ITER


Models: summary of what is needed“Deliverables: In the next decade the programme must deliver:

b) The capability and tools for accurate predictive modelling of ITER performance. These tools must integrate models of confinement, stability, energetic particle physics and wall interaction. Their validation should be prime programmatic objectives of the accompanying facilities.”

Comprehensive suite of theory-based models for the major issues of the core plasma, with clarity on the state of experimental validation

Models for SOL, divertor and first wall, including some 3-D effects (e.g. ELM coils). Some semi-empirical due to mixed plasma and non-plasma physics.

Structure to integrate the codes (ITM)

Note: no Association proposals for the massive computing resources that will be needed as well as IFERC if we aspire to a full model?


Staffing proposed by AssociationsWhile no breakdown has been made at this stage, the totals may be useful (there are certainly errors here!):

Period Total ppy Av. ppy/yr 2a 2b 2c*

2012-2013: 1458 729 372 218 138

2014-2018: 3375 675 357 208 110

2019-2020: 1448 724 317 212 195

Total 6279 - 3162 1900 1216

* 2c includes increased staffing for AUG to make more available, MAST Upgrade, some facilities and diagnostic development, as well as TS (WEST), AUG extension, and FAST


Facilities 2012-13 (Host input)FP7 Tokamaks, RFPs, Stellarators

ASDEX UpgradeCOMPASSFTUISTTOK (?)JETMASTTCV (+ TORPEX)TEXTORTORE SUPRAEXTRAP-T2RRFXTJ-II

Observation: all machines appear (to a different degree) in the proposals, some are heavily used by several Associations


Facilities 2012-13 (Host input)Plasma source, PWI, high heat flux etc

• Magnum-PSI (FOM)

• JUDITH 1, JUDITH 2, MARION, PSI-2 Jülich (FZJ)

• PUMA(?), PF1000-U (IPPLM)

• ELISE (IPP), FNG (ENEA), Remote handling (?); HELOKA (KIT); OMEGA (PWI?, ENEA); Tandem accelerator (VR)

Computational (fusion specific)

• Gateway, HPC-FF, IFERC



ASDEX UpgradeCOMPASSFTUISTTOK (?)JETJT-60SA (late in FP8)MAST (and upgrade)TCV (+ TORPEX)TEXTORTORE SUPRAEXTRAP-T2RRFXTJ-IIW7-X

Some are absent in 2019-20, but closure date not given if earlier




• JUDITH 1, JUDITH 2, MARION, PSI-2 Jülich, JULE-PSI (FZJ)

• PUMA(?), PF1000-U (IPPLM)

• ELISE (IPP), FNG (ENEA), Remote handling (?); HELOKA (KIT); OMEGA (PWI?, ENEA); Tandem accelerator (VR)





ASDEX UpgradeCOMPASSFTUISTTOK (?)JET (?)JT-60SAMAST (upgraded)TCV (+ TORPEX)TEXTORTORE SUPRA (if WEST)EXTRAP-T2RRFXTJ-IIW7-X




• JUDITH 1, JUDITH 2, MARION, PSI-2 Jülich, JULE-PSI(FZJ)

• PF1000-U (IPPLM)

• ELISE (IPP), PRIMA (RFX), FNG (ENEA), Remote handling (?); HELOKA (KIT); OMEGA (PWI?, ENEA); Tandem accelerator (VR)




JETJET has a special place in this period, in some ways a proxy for ITER.

Here, it is assumed JET is available for some years (e.g. to 2015)

A tritium campaign would change tenor of EU programme significantly.

Association input covers all of the main areas and includes

• Scenario development to high power with radiative divertor

• Integrated ELM control

• Fuel retention, and removal

• Material erosion and migration (W, Be)

• Fast particle physics and diagnostics

• Disruption studies including runaways, avoidance, prediction, mitigation

• ICRH performance


Satellite facilities proposed/agreedBA: JT-60SA (some Associations propose diagnostics)

CCFE: MAST Upgrade [Objective 4 as well]

CEA: WEST (Tore-Supra + actively cooled W divertor) [Objective 4 as well]

ENEA: FAST and its subsystems

FZJ: Upgrade high heat flux test facility (MARION), Hot cells with plasma devices, Linear plasma device (JULE-PSI?)

HAS: TBM Remote Handling test facility [Objective 1 or 4?]

IPP: ASDEX Upgrade extension

IPPLM: Pulse Plasma Gun (PUMA) for disruption, ELM studies

IST: Remote Handling Transfer Cask System test facility [Objective 1 or 4?]

In addition several Associations mention diagnostics and other support projects


Forward look to the ITER yearsThe situation will be different when ITER is operating:

• Focus on designing plasma scenarios and experiments to develop and optimise them. Likely to be largely modelling (discrete and integrated), using experimental data to test.

• Powerful and fast tools for analysing and interpreting data will be key.

• Non-ITER studies could be focused on specific problems (e.g. transport, transport barriers, stability, anomalies in current drive, fast ion physics etc; preparing enhancements).

Not clear when ITER takes on scenario integration – maybe for deuterium, not hydrogen? Transition may not be at end of FP8+2

ITER will not address steady state/very long pulse till later – need to develop in parallel (modelling and experiment). JT-60SA will be key.


Short version…Break down scenarios into the known problem areas (Associations, ITPA, Facilities Review, ITER research plan etc)

Think what we can do which can genuinely be applied on ITER plasmas to reduce risks and/or make them better (“think like ITER”)

• identifiable output (i.e. we know when we’ve done it)

Identify which Associations interested, facilities available

This can be basis of a roadmap rooted in a practical programme

Some summary info from the input


Summary and conclusions - ITo get the best from ITER, quickly, we need motivated, able, experienced people, and a suite of tools to design and optimise plasmas

Genuine scenario demonstration can only be done on ITER, documentation alone is completely inadequate. [A mechanism to include expert people in the “ITER team” is key, especially as facilities close].

But many things can be done to prepare the people and the tools

Approach:

• break down scenarios into elements (e.g. pedestal, L-H transition, core transport, ICRH coupling), and integration issues,

• pick those where there is concern and genuine potential to develop tools to improve ITER plasmas, define specific goals (imagine we are ITER)

• demonstrate improvements on smaller tokamak(s) and models, and thus take a proven theory-based technique to ITER (imagine we are ITER)


Summary and conclusions - IIThis gives ingredients for a strategic roadmap in scenario development (experiment + theory), rooted in a stimulating research programme.

They could help define the necessary programme size for Europe to maintain and develop an independent capability for ITER and DEMO

Scenario integration will pass to ITER, but possibly only after the hydrogen and helium phases, i.e. significantly into FP9.

While the emphasis is naturally on larger better equipped tokamaks, there are important roles for other facilities, including stellarators & RFPs. Also need space for new ideas, exploration

It appears a viable accompanying programme reducing substantially the risks for ITER operation can be built from Associations’ input.

To do: assessment of satellite facilities needed in parallel to ITER operation


More detailed slides on scenario issues…List of Facility review milestones

[Available on request]

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