PERSISTENT SURVEILLANCE FOR PIPELINE PROTECTION AND THREAT INTERDICTION

1. Diagnostics and Control Presented byR.L. Boivin With contributions from D. Johnson, D. Gates, K. Young (PPPL) D. Humphreys (GA) and S. Allen (LLNL) Burning Plasma Organization Workshop Oak Ridge National Laboratory December 7-9, 2005 PERSISTENT SURVEILLANCE FOR PIPELINE PROTECTION AND THREAT INTERDICTION

2. Diagnostic and plasma control systems will be an important entry point to ITER/BP science • ITER is a US project • We have to be involved to make sure it will achieve the science we particularly care about. • The diagnostic work is a shared responsibility • Approximately 32 systems - 6 to the US • 6 parties (soon likely to be 7) • We should care about all • The control system will ensure that we achieve the science • Presently assigned to IT • Need to coordinate both aspects together

3. How should diagnostics and control interact within the BPO? • Presently the Diagnostic and Control groups are 2 separate working groups • We support this arrangement • However, clearly, there should be strong ties between the 2 groups • Seek to obtain the best set of measurements and diagnostics • Integrate diagnostics within plasma control system • Identify interactions with actuators

4. Overview - Control since Snowmass • Plasma Control • Awareness of different needs for burning plasma devices • Extensive designs for ITER axisymmetric control, CODAC spec • Initial development of solutions for nonaxisymmetric and realistic operational control being explored on operating devices • In the US • Extensive development of nonaxisymmetric and advanced operational control on existing devices • Beginning of analysis and design for some ITER-relevant control needs • Control Needs of ITER; now and near future • Critical need for specific impacts on design • Development and demonstration of BP-relevant control on operating devices • Realistic, validated, and ITER-specific models and control tools Plasma Control

5. Recent ITER control design continued with minimal participation of the US • Selected Control Developments Outside the US: • Axisymmetric control design advances, highly focused on ITER • Control schemes, design/testing tools developed, modeling/simulation tools • Controllers designed and simulated satisfying key performance specs • Advanced controls pursued at JT-60U, JET, TCV, ASDEX, Tore Supra… • Extensive progress in organizing control resources in EU, Japan, RF (mostly separately) • Selected Control Developments Inside the US: • Development of operational controls for present experiments • Great progress in advanced stability control (particularly RWM, NTM, ELM) • Continued development of many relevant physics codes • Development of control modeling/design/simulation tools to support present experiments • Control analysis/simulations, (e.g. for FIRE) • Limited ITER-specific control analysis/simulation • Design/implementation of control systems and algorithms for next-generation SC tokamaks (KSTAR, EAST) Plasma Control

6. Diagnostics since Snowmass - A large number of measurements are envisioned for ITER Need to complete an objective determination of performance - review Diagnostics

7. Techniques have been identified to meet those measurement needs In Blue: Uncredited Systems Diagnostics

8. We need to reinvigorate the US effort for ITER diagnostics design and R&D work • In Engineering Design Activity Phase (<1999) • US delegates were active in Diagnostic Expert Group Meetings, system designs and R&D • 2001 - present, International Tokamak Physics Activity (ITPA) • Active in ITPA Diagnostic Topical Group Meetings • Membership in many Diagnostic Specialist Working Groups • Presently Participating in Port Engineering Task Force • Defining requirements, developing design of generic plug structures, roles and responsibilities, logic for testing and delivery • EU will build equatorial prototype, JA upper prototype • From 2000-2004, there was no design work in US Diagnostics

9. US contribution to the ITPA-diagnostic group is essential to the success of ITER diagnostics • Specialist Working Groups (3-5 members) • Neutron • Reflectometer • First mirrors • Radiation Effects • Thomson • Passive Spectroscopy • Beam-aided Spectroscopy • Members • D. Johnson • R. Boivin • G. McKee • T. Peebles • G. Wurden • Many additional contributors in Specialist working groups (SWG) • Open to all • Good entry point for participation Diagnostics

10. High Priority ITPA tasks highlight opportunities for the the BPO related R&D • Alpha particle diagnostics • Confined: is collective scattering sufficient? • Escaping: is there a workable solution? • First mirrors • Can they survive the environment? • Radiation effects • Can we make reliable magnetics measurements? • Dust measurement • Do we have a reliable technique? • Vertical Neutron Camera • What are the physics needs, and can we implement it? Diagnostics

11. ITER diagnostics have been provisionally allocated • In 2003, DWG was formed with delegates from 6 parties and IT to: • consider ‘port-based’ diagnostic procurement packages • propose a party allocation • Port-based packaging of diagnostics • Not individual diagnostic systems, instead assigned to ports as ‘lead diagnostic’ • Party providing lead diagnostic is also responsible for providing the port plug, and for ‘integrating’ all of the diagnostics into the plug • ITER IT brokered a sharing proposal • each party to provide prioritized list of packages • In the US, list was created based on assessment that included a ranking by 10 tokamak diagnostic experts. • IT then proposed allocation, with a target share for each party (US - 15%) • IT iterated in private with each party to convergence • Parties gave provisional agreement to proposal in 2004 Diagnostics

12. Party Sharing of Diagnostics • The US is responsible for 16% of the credited systems versus 10% for its total contribution • This is a provisional arrangement • Remains open questions for uncredited and new systems • Opportunity for the community to participate in this effort through the BPO Diagnostics

13. These packages reflect a variety of techniques Target total credit Assigned leading port Credit value(%) Total credit Package # Note that package 13 (ECE) also includes the toroidal interferometer and polarimeter. Diagnostics

14. Integration is a major aspect of diagnostic packages Upper Plugs (U5, U17) Viewing system(vis + IR) LFS reflectometer Equatorial Plugs E3: MSE E9: ECE + Interf./Polar) Divertor Side Panels and Support Structures(L8) • Interferometer Diagnostics

15. Example of physical integration: MSE within Port E3 • Design constraints (examples) • Numerous labyrinths, many with precision optics • Provide access while limiting neutron streaming  urgent need for efficient neutronic analysis tool • Provide attachments and cooling to blanket shield modules • Port E3 is a US responsibility • US will provide the MSE system as the ‘lead diagnostic’ • US is also responsible for integrating the following into port E3 • Two Visible/IR camera views (EU) • Two edge CXRS views (RF) • H arrays (RF) Diagnostics

16. Measurement requirements are important for both science and control • The US community has an opportunity to review and influence the determination of measurement requirements in the near-term • Important for scientific achievements • Crucial for control development • Essential for AT development, for example • Requirements come with a “price” • Needs careful justification • Performance simulation is a very good approach to optimize systems. • Entry point for BP science

17. The BPO and the community should take the opportunity to complete a comprehensive review of requirements 1) Electron Temperature Profile: The electron temperature, with good spatial dependence, is a major indicator of performance in the control room and a key component of transport analyses. The profile is key information in instability analyses. Steep transport barriers are observed inside the plasma core and electron temperature pedestals at the edge play a role in analysis of the transport. A time resolution of 10 ms is short compared to times of interest and allows for study of MHD and good development of the time behavior. If, as expected, the profile will be used in plasma control, this time resolution will be necessary for calculating the profile, averaging and inputting a control signal with ~100 ms resolution. The core temperature should be measured with 10% accuracy and at 30 locations across the profile to be able to define the profile sufficiently well. The edge, with much steeper gradients should be measured with only 0.5 cm between measurements at about 20 locations.

18. ITER Requires Extensive Control Design • Shape/position/axisymmetric stability control requirements are unprecedented: • Shape control accuracy/precision • Dynamic control in presence of large disturbances • Coil current and voltage limits with greatly reduced margins • AC loss limits • Divertor integrity, heating, fueling, burn control • AT control: • Current and pressure • High performance axisymmetric/MHD control • Error field correction with SC coils; coordination with MHD control… • Off-normal response systems: • Disruption prediction, corrective action, mitigation • Extreme reliability requirements throughout system • Nuclear licensing/commissioning requirements • Necessity for hardware/software performance verification • Highly constrained operating procedures - offline design/testing Plasma Control

19. Selected High Priority ITER Control Tasks/Needs • Shape/position/profiles/axisymmetric control: • Complete long-pulse solution incorporating coil current and AC loss limits • Noise effects/solutions (particularly from ELMs, etc…) ITPA • Current profile control ITPA • MHD Stability control: • RWM control solution, validated models and analysis of capabilities, effects of ELMs, n>1 modes, active RFA/EF control ITPA • NTM control solution/ validated models of island evolution, rotation effects, modulation effectiveness, sawtooth control, error field effects ITPA • Experimental demonstrations of ITER-relevant RWM, NTM solutions ITPA • ELM control/mitigation ITPA • Off-normal response systems: • Disruption prediction, corrective action, effective mitigation methods/triggers ITPA • Integrated, high reliability supervisory system design • Licensing/commissioning requirements • Development and demonstration of hardware/software performance verification with full scenario simulations Plasma Control

20. The US Has Unique and Critical Resources for All Elements of ITER Control Design Process • Physics expertise • Computational tools • High performance, well-diagnosed experiments with powerful, flexible control capabilities • ITER relevant physics exploration • Demonstration of ITER control approaches, scenarios • Physics validation • Control modeling codes • Experimental validation • Control design codes • Relevant advanced design experience • PCS/algorithm test and verification with simulations • Experimentally proved algorithms • Plasma control system software, expertise • - Operational experience with advanced control Plasma Control

21. The ITER CODAC offers a great opportunity for the US • CODAC (Control and Data Acquisition Computer) presently “assigned” to the central (IT) team. • Plasma control is an area with high impact metrics: • Central to ITER experimental operations and physics • Following US departure from EDA, other Parties and JCT pursued the effort; EU in particular established: • Strong inter-organizational coordination, EU-wide integrated control program • Strong coupling between experimental programs and control R&D • US has potential to re-take leadership role OR to strongly complement other Parties/IT with unique tools/expertise in both R&D and CODAC task - US Strength • In order to play a role in ITER plasma control, the US, through the BPO, should coordinate and support: • Continuing development of ITER-relevant plasma control methods/tools • Design and implementation of ITER-relevant controllers on experiments • Experimental time to explicitly perform predictive model construction and validation • Strengthened coupling among codes/theory/experiment and control design Plasma Control

22. Organizational Issues • BP Diagnostic work has to refocus • Specific task and R&D for allocated packages • Coordination with the Project • Dedicated R&D for open issues and new opportunities • Uncredited systems • Unmet measurement requirements • In addition the BPO should provide • Opportunities for US researchers for contributing to non-US packages • Mechanisms for proper review and input from US experts • This will require strong ties with the USIPO and the community in general. Diagnostics

23. BPO Structure: Coordinate US Plasma Control Activities towards ITER’s Technical and Scientific Success Some Key Questions: • How can the BPO advocate the US positions and strengths on control to have the greatest impact on ITER? • What are unique US capabilities and strengths in control? • Model based control design, simulation,and verification • Active MHD control (RWM, NTM, ELMs) • Integrated multivariable control to achieve steady state advanced scenarios • Modeling and integrated systems simulations • Integrated control experiments,model validation • Burning Plasma control is “cross cutting,” affecting many physics and engineering aspects. How can we (BPO Operations and Control group) best communicate and coordinate with • Other BPO groups, • US ITER Project Office, • ITER Interim International Team, • Other ITER Parties ? Plasma Control

24. Summary • The development of diagnostics for BPX (including ITER) present many challenges and opportunities • The US community has to become engaged • A good mechanism for this work has to be developed • A clear opportunity exists for the US community to create an excellent control system for ITER • Coordination is key