Discussion - IMAGE

1. Discussion - IMAGE ITPA Lausanne 2007 P. Strand

2. Integrated modelling collaborative activities • This discussion: • Need to decide/discuss: • Overlap – collaboration opportunities • Collaborative formats • Timescales • Next meet Naka? • Standalone meeting? • Other topics to include? • In sessions & Thursday am • Create teams • Sketch Workplans • Discussions in Vilamoura (2004) and Princeton (2006) • Standardization of formats and interfaces • Machine descriptions • Transport Solvers • V&V metrics and standardized test cases • Software Standards • Relation to ITER modelling and ITPA task • All discussed in session at this meeting IPTA LAUSANNE – IMAGE kickoff, 2007, P. Strand

3. Session discussions • Examine collaborative interests • Indicate list of general tasks and activities neded • Select team coordinator • Initial list of Team members • “Workplan” • In order to

4. ITER Integrated Modelling Framework I • 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 ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007

5. ITER Integrated Modelling Framework II • 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 ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007

6. ITER Integrated Modelling Framework III • 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 ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007

7. ITER Integrated Modelling Framework IV • 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 ITPA CDB&M and TP Topical Group Meetings, Lausanne, 7-10 May 2007