1. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 1 D Campbell ITER International Organization Acknowledgements: W Houlberg, V Mukhovatov, A Polevoi, P Strand, and many colleagues in the international fusion community ITER Integrated Modelling Needs

2. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 2 ITER scientific programme scope activities implementation tools ITER Modelling Needs project requirements physics and operational needs ITER Integrated Modelling Framework collaborative structure for integrated modelling development activities required Summary Synopsis

3. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 3 Main elements and organization of the ITER scientific programme under development We can foresee the ITER scientific programme developing along 2 major lines: provision of the necessary technical support to the ITER construction project development of plans for ITER plasma commissioning and exploitation phases  scientific framework and programme for ITER exploitation We aim to establish ITER as a centre of excellence in fusion research with an extensive interaction with the research programmes of the ITER Members ITER Scientific Programme

4. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 4 Provision of necessary technical support to ITER construction: support and contribute to the ITER Design Review collaborate with Members’ fusion communities to resolve key R&D issues on timescale required by ITER construction schedule ensure that performance requirements and design choices reflect the state-of-the-art in fusion science  effective interface with the Members’ research programmes support specification of operational requirements, design development and performance analysis of sub-systems influencing plasma performance (eg H&CD, Diagnostics, Fuelling, CODAC, PFCs) support the project’s licensing application maintain an up-to-date specification of ITER performance requirements provide an in-house capability for ITER plasma performance projections ITER Scientific Programme: Current Priorities

5. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 5 Development of plans for ITER plasma commissioning and exploitation phases  scientific framework and programme for ITER exploitation: refined set of ITER reference plasma scenarios  design basis for the tokamak/ auxiliary systems  model plasmas for detailed study in the Members’ programmes define requirements for ITER plasma control system develop physics definition of control strategies and algorithms develop a comprehensive modelling capability - builds on activities in Members’ programmes lead programme of research in the fusion community to explore/ document ITER’s potential as a burning plasma experiment elaborate a detailed plan for commissioning and scientific exploitation of ITER in collaboration with Members’ fusion communities  ITER Research Plan ITER Scientific Programme: Operation and Exploitation

6. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 6 Implementation of Physics research programme will require a range of mechanisms, utilizing resources within Members’ domestic programmes: Programme of Physics Design and Research Tasks: defined within annual project workprogramme and managed through ITER Task Agreements implemented via Domestic Agencies Co-ordinated physics research activities implemented on an international scale: develop the Physics Basis for ITER operation integrate results of fusion programmes of ITER Members’ into planning of ITER operation ITER Scientific Programme: Proposed Implementation Mechanisms

7. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 7 Establishment of a programme of integrated modelling of fusion plasmas: would exploit existing co-ordination structures where possible, building on activities within Members’ domestic programmes Attachment of Visiting Researchers to IO: contribution from each Member would enhance implementation and co- ordination of physics activities Establishment of post-doctoral and PhD programmes: brings younger researchers into the ITER process exploits ITER’s potential for training fusion researchers invests in preparations for operational programme ITER Scientific Programme: Proposed Implementation Mechanisms

8. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 8 What are the project requirements driving the ITER modelling needs? Provision of a design basis for the ITER facility (2007+): ITER Design Review depends extensively on state-of-the-art modelling ITER performance predictions must adapt to design evolution Plasma scenario development: Reference scenarios continually updated (2007+) Preparation for operation (~2010+) Auxiliary systems (2007+) H&CD, Diagnostics, Fuelling … Plasma Control (2007+) Design of PF control system Evaluation of requirements for mhd control  design Evaluation/ definition of kinetic control requirements Evaluation/ definition of protection systems Development/ optimization of integrated control strategies (~2010+) ITER Modelling Needs I

9. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 9 What are the project requirements driving the ITER modelling needs? Preparation of ITER operational programme: End-to-end scenario development (~2010+) Development of experimental campaigns (~2012+) Detailed pulse definition (~2014+) Experimental data evaluation (2016+): Pulse characterization Physics analysis Scenario refinement Optimization of auxiliary systems Refinement of performance predictions Many common physics elements among these requirements  an integrated and common approach necessary to ensure: Access to latest developments Broadly based analysis Consistency among studies ITER Modelling Needs II

10. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 10 The novel aspects of burning plasma physics at the reactor scale influence many aspects of ITER’s modelling needs Size scaling of plasma phenomena (dimensional/ non-dimensional): Core energy and particle transport Influence of reduced input torque and likely lower rotation Core-edge integration (ITER plasmas represent a new regime) Divertor behaviour and plasma-wall interactions MHD stability and mhd control requirements: ELMs, Disruptions Sawtooth, NTM, RWM control Energetic particle physics: confinement, influence of self-heating, mhd drive studies across range of possible operating scenarios Burning plasma scenarios: Transport barriers and their control Possible non-linear interactions between heating, pressure, rotation and current profiles ITER: a Burning Plasma Experiment

11. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 11 ITER will need comprehensive modelling tools to develop self- consistent scenarios - heavy demands on physics and computing Need integrated plasma models with varying computational demands: Various activities: scoping, scenario development, proposal development, pulse preparation … Plasma control integrated in more advanced stages: Need good models of H&CD, diagnostics, fuelling … Physics of control must be incorporated Self-consistent plasma and machine operating limits Must handle range of scenarios robustly: Ohmic, L- and H-mode, Hybrid, non-inductive …  -particle physics must be as complete as possible Sophisticated input/ output requirements: Interactive control of simulation to allow “steering” of scenario development (?) Output manipulation and visualization tools essential to enhance efficiency of development process ITER Plasma Scenario Development

12. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 12 Integrated plasma control capability will be as much a modelling as an experimental tool Modelling will allow testing of many ideas for plasma control: Modelling a necessary component of design optimization of feedback control systems (NTM, RWM …) Study viability/ reliability, fine tune control algorithms/ parameters … Success/ failure in experiments will guide model development All plasma control techniques must eventually appear in models: Self-consistent plasma scenario development will rely on this Heirarchy of control actions needs to be established (facilitate scenario development etc) Varying levels of model sophistication will be required, adapted to activity requirements: Algorithm development/ tuning, scenario scoping, full scenario demonstration have different demands ITER Plasma Control

13. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 13 A comprehensive modelling capability for burning plasmas will be an essential ITER “sub-system” Can expect that all experimental proposals will need to be accompanied by modelling justification: Need to demonstrate that sought after result is credible within ITER’s operating capability Detailed pulse planning will require end-to-end modelling: ITER’s experimental time valuable Need to identify potential hazards for device and plan countermeasures, eg identifying and avoiding operational limits May need to tune control parameters Evaluation of pulses will require extensive modelling: Should aim to ensure that many “extended” calculations of pulse parameters should become routine, eg heat and particle transport coefficients Need to evaluate proximity of real pulse trajectory to predicted trajectory May need to provide rapid turn-around in fine-tuning of pulses for directing experimental session Benchmarking of models at ITER scale fundamental activity ITER Experimental Operation

14. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 14 ITER needs to start working to develop the required tools now The ITER IO and the ITER community need common tools to address the ITER modelling requirements: Need to ensure that we have a common basis for all statements about ITER There may be several/ many varieties of a given code module, but all users in the ITER community should be capable of using them ITER IO needs an in-house capability to explore ideas, to test results emerging from physics community, and to respond rapidly to ITER project needs But ultimately the modelling basis for the ITER scientific programme should be a common project of the IO and the Parties physics communities ITER IO will rely heavily on the Parties’ physics communities: ITER IO will be seriously limited in size The international physics community is an extensive reservoir of expertise and talent There is an emerging consensus in the international community that the way forward in developing a better understanding of fusion plasmas is to integrate the knowledge incorporated in the individual codes describing different phenomena ITER Integrated Modelling Framework I

15. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 15 What are the activities which we need to pursue? The ITER Members have indicated their support for the establishment of a dedicated ITER framework for integrated modelling The IO would like to build on the integrated modelling initiatives in the Parties’ fusion programmes We need to develop common data and software frameworks for developing the ITER tools: Must make efficient use of international modelling community Should provide low “threshold” for access of new contributors/ users Integrated modelling activities in Parties and IMAGE are important initiatives in this direction We need to agree a programme of model development and integration: Set priorities and timescales Allocate responsibilities and tasks We need to identify adequate computing resources Essential to establish an accompanying programme of model validation: Collaboration with Parties’ fusion devices and ITPA ITER Integrated Modelling Framework II

16. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 16 What would be the products of this collaborative activity? An agreed development framework for an integrated model of burning plasmas The framework would be guided by the overall ITER project schedule, but defined in collaboration between the IO and the Parties fusion communities An agreed programme of code development There would be well-defined goals (and some open lines of research) A common structure for data exchange and code development across the ITER collaboration: Must make efficient use of international modelling community A programme of code validation as an integral component of the activity: Implemented in collaboration with fusion facilities and ITPA A broadly-based modelling activity on ITER scenarios Supports wide exploration of ITER’s operational capabilities Contributes to optimization of operational scenarios (eg tuning of control) A comprehensive documentation of models and their validation Required, at some level, by ITER QA Essential to encourage international interchange ITER Integrated Modelling Framework III

17. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 17 Code modules to be incorporated in the ITER reference suite must have full documentation, meet well-defined verification standards and have been subject to adequate validation: Documentation requires a clear explanation of physical model and all I/O, strengths and weaknesses of physical model, verification, and validation procedures: Implies standardized units (MKSA), definitions of quantities, equations in forms which can be readily applied to experimental situation and cross-checked Verification implies that a computational model correctly represents a theoretical or empirical expression of the physics Usually accomplished by comparisons with manual/ analytic calculations or well-established and verified codes Validation involves demonstrating that a computational model represents the experimentally observed physics: Usually requires comparison of code with experimental results or with an existing code validated in relevant regime Establishing robust procedures needs a significant and co-ordinated community effort: Need to satisfy IO needs and gain support of the modelling community ITER Integrated Modelling Framework IV

18. ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007 18 The establishment of a framework for the development of an integrated model of burning plasmas is a central activity of the ITER scientific programme Integrated models of fusion plasmas will have several key roles within the ITER project and the ITER community ITER IO foresees establishing a new framework for the co-ordination of this activity (supported by the ITER Members) Framework will build heavily on the integrated modelling activities being established within the Parties’ fusion programmes - will draw heavily on Parties’ manpower and computing resources Framework also a mechanism to integrate the fusion programmes of the ITER partners into the ITER scientific programme The development of an integrated model of burning plasmas is one of the major scientific challenges accompanying ITER construction and operation The proposed framework is intended to support ITER needs, promote advances in modelling of fusion plasmas and encourage research on ITER burning plasmas Summary