ITER Integrated Modelling – Status & Plans

1. ITER Integrated Modelling– Status & Plans W.A. Houlberg ITER Organization 3rd ITPA Transport & Confinement Meeting Princeton, NJ 5-7 October 2009

2. Outline • The ITER IM Programme: • Scope • Initial and boundary conditions • Predictive and interpretive analyses • Coordination between IO and Domestic Programmes • Status and plans: • Documentation • Website development • Computing cluster • Databases • Plasma control • Summary

3. Scope of the ITER IM Programme • ITER IM is responsible for all of the physics models and codes used in ITER predictive and interpretive analyses • ITER, as a nuclear facility, will require a well-documented core of physics codes to be applied systematically to every discharge: • Predictive: analysis of control requirements and operation within bounds of ITER system capabilities • Analysis: processing diagnostic data into temporally and spatially resolved physics parameters for real-time display and subsequent detailed analyses • These core physics codes are expected to be based on reduced models for efficient application • The core physics codes must be available to all users (with appropriate training) • The core codes will be backed by more comprehensive physics codes: • This is where the more extensive suite of codes and resources in the Domestic programmes play a dominant role • These more comprehensive codes will link to the ITER experimental and systems description data through the same set of interfaces as the core codes A modular/component structure is required to satisfy these needs

4. Initial and Boundary Conditions • The seeds for the ITER IM Programme were sown by plans and discussions in the Domestic Programmes • The ITER IM Programme is ambitious: • It is broad in scope • It entails physics objectives beyond what we are presently capable of describing with present theories or models, or have yet explored in experiments • It is designed to match the ambitions of the ITER Project • It can only be accomplished through strong collaboration between the IO and Domestic Programmes • The expectation is that Integrated Modelling will continue to mature over the ~30-year life of ITER: • The ultimate Integrated Modelling capabilities are not limited by present physics knowledge or tools • Theories, models, experimental observations and computing capabilities all will improve • We must build a framework to accommodate these improvements

5. Predictive Analyses • Supporting the design basis and its evolution: • Plasma magnetic control, H&CD and fuelling systems • Evaluation of upgrade options • Scenario studies: • Scoping with reduced models, backed by comprehensive calculations • Heating, fuelling and CD strategies • Campaign development: • Stability, control and diagnostic requirements, alternatives based on subsystem availability, system limitations, fault amelioration techniques, sensitivity of operation to uncertainties • Plasma control: • Control strategies: plasma response times, sensitivity of plasma to actuators, impact of events • Input to control algorithms: gains and response times with idealized sensors • Testing control algorithms: simulate plasma behaviour using control algorithms with synthetic diagnostics linked to actuators • Physics components for control: provide CODAC with robust, well-validated real-time physics models (e.g. equilibrium reconstruction) • Expect all of these applications to include extensive input from the community, e.g. scenario studies by the ITPA IOS TG

6. Interpretive Analyses • Real-time analysis: • Display of physics parameters using fast conversion of diagnostic signals • Systematic employment of in-house suite of validated tools • Simultaneous display of modelled results in control rooms (local and remote) • Post-processing: • More rigorous conversion of diagnostic signals emphasizing consistency in analysis, uncertainties (error bars), … • Systematic employment of in-house suite of validated tools for inter-shot and overnight processing • Model validation and improvement: • More detailed, long-term analyses of selected cases • Relies heavily on more extensive modelling capabilities within the ITER Parties • Physics codes for real-time and post-processing are to be based on tools used in present experimental programme: • Joint effort between IM, Diagnostics and developers of ITER diagnostics

7. ITPA and IMEG Roles • ITPA – emphasis on R&D activities: • Databases to describe plasma characteristics over a wide range of conditions, with particular emphasis on areas where theory and models provide inadequate coverage • Model development and validation against experimental observations • Projections to ITER operation using a combination of experimental observations and validated models • IMEG – emphasis on IM infrastructure: • Identification of a required core suite of in-house codes and tools for systematic prediction and analysis of every discharge and available to all ITER Members • Rely on adaptation of existing codes and tools • Core suite must be computationally efficient and well validated • Establishment of standards and guidelines for the core suite (documentation, verification, validation, modularity, maintenance, …) • Required for coordination and integration • Identification and implementation of means to link to more in-depth analysis of selected cases using codes available within the ITER Members IM Programmes • For example, more advanced physics models requiring high performance computing, new approaches to coupling physics • Definition and development of the internal and remote user environment

8. Integrated Modelling Expert Group (IMEG) • IMEG responsibility is to assist the IO in defining and developing the ITER IM Programme, based on the experiences and capabilities in their Domestic IM Programmes • IMEG Members (coordinator) • CN Li, J. Dong, J. Zhu, S. • JA Mori, M. Fukuyama, A. Ozeki, T. (Deputy Chair) • KO Jhang, H. Yoon, S.W. • EU Thomas, P. McDonald, D. Strand, P. (Chair) • RFKonovalov, S.Medvedev, S. • IN Bandyopadhyay, I. Bisai, N. Srinivasan, R. • US Van Dam, J. Batchelor, D. Lao, L. • 1st IMEG meeting held 23-26 June 2009: • Reviewed ITER IM Programme objectives and approach • Surveyed related modelling efforts in ITER Parties • Reviewed initial draft of ITER IM Standards & Guidelines, and plans for additional documents • General consensus – very fruitful initial dialog, we all have a lot of work to do and it must be well coordinated

9. ITER IM Documentation IM Programme Near completion Started Initiate Explore options Procedures & Conditions for Accepting External Simulations Procedures & Conditions for Accepting Elements into IMAS Standards & Guidelines Computer Hardware, Software & User Access Predictive Analysis Tools Databases Interpretive Analysis Tools Scientific IMAS - Integrated Modelling Analysis Suite - In-house codes available to all parties Implementation User Guide

10. Websites Under Development • Sharepoint websites for FST Department, each section, ITPA taking shape: • Links to FST-related items in IDM make it much easier to find information

11. Migration of ITPA Website from IPP-Garching to ITER • ITPA website(s) – site with general information, separate sites for CC & TGs • In Sharepoint (ITER’s standard web tool) • Public information available through ITER Public website • Private information through ITER Technical website (require ITER account) • Expected features: • Uniform system for contacting various groups by e-mail • Links to ITER Research Needs and other communication between ITER and the ITPA • Links to external private TG working sites if necessary (e.g. DBs) • Document management, publications, meeting info • Responsibilities: • Technical information: ITER Deputy Chairs, CC secretary will have primary responsibility, supported by other volunteers designated by the ITPA • Design, development and overall management: Masanari Hosakawa

12. ITPA Public Website (not yet published) Future meetings, links to local websites Click on box to enter Private Site

13. IM Elements and Integration with ITER Systems IM elements Interpretive Analysis Database Control algorithms Diagnostic signals Validation of synthetic diagnostics Control Loop Simulated diagnostic signals Synthetic diagnostics ITER Facility Simulated plasma data Model validation Processed plasma data Data interpretation Simulation Engineering data Predictive Analysis

14. ITER IM Database Plans • Example of using tools developed by ITPA and the community: • Install MDSplus • Import copy of ITPA Profile Database (PDB08) and tools from Culham to use aa a template for initial construction of an ITER DB: • Tree structure for scalar and profile data from many experiments and some reference ITER cases: C. Roach et al, Nucl. Fusion48 (2008) 125001 • Tree structure for MHD equilibrium, SOL and divertor data developed by ITPA Pedestal & Edge Physics TG added, but presently not used in PDB • Documentation http://tokamak-profiledb.ukaea.org.uk/DOCS/ • Unify tools for submission of ITER simulations, data checking, visualization • Assess extensions and unification for ITER reference cases: • Additional trees will need to be added, as well as other data structures to describe the ITER configuration

15. Defining IM Role in Control Requirements • System requirements for control are being defined now • Plasma Control System (PCS) – FST responsibility (physics algorithms and models), but also: • Part of a defense strategy but no direct responsibility for safety • Defense against disruptions, excessive machine conditions, … • Evaluates severity of conditions and may change operational sequence • Controlled termination if needed, or request CIS to intervene • Central Interlock System (CIS) – CODAC responsibility, primarily for investment protection: • Failure or loss of PCS – takes control if thresholds exceeded • Emergency plasma termination – triggers mitigated disruption • Likely a long recovery time before next shot – ~hours • Central Safety System (CSS) – CODAC responsibility, primarily for personnel and nuclear safety: • Triggers on failure of PCS and CIS or fault condition with safety implications • Shuts down operation (nuclear incident)

16. All Control Integrated within the CODAC Environment

17. Plasma Simulator in the Control System • A Plasma Simulator is envisioned as part of the control system: • Must be validated, robust and fast for discharge verification • Checks proposed discharge against machine capabilities – weeks in advance, and again on day of operation: • H&CD and fuelling system availabilities • Operational boundaries • Diagnostic requirements • Control features • Capabilities needed: • Full plasma control (free-boundary equilibrium with transport) for discharge design and verification • Efficient, validated physics models (including the core, pedestal, SOL, divertor) • Synthetic diagnostics for comparison with real-time measurements • Simultaneous display of expected performance form simulator along with data from discharge evolution • Integrated Modelling responsibility to develop simulator: • Operation and maintenance responsibilities TBD

18. Summary • The ITER IM Programme describes an ambitious effort that designed to match the ambitions of the ITER Project • It can only be accomplished through strong collaboration between the IO and Domestic Programmes: • ITPA for investigating the experimental and theoretical bases for physics issues of relevance to the ITER research programme, validating models, and providing assessments of the impact of these issues on ITER operation • IMEG for establishing the infrastructure for integration of physics models across a variety of applications and origin of the computational models • The expectation is that IM (in both the ITER and Domestic Programmes) will continue to mature over the ~30-year life of ITER, and establish a solid basis for design and construction of DEMO • Near-term emphases: • Define needs, organization, development approach • DBs for facility description and simulation results • Websites for enhanced communication • Establish basic infrastructure and development schedule