DISCUSSION OF ISSUES, OPPORTUNITIES AND CONCLUSIONS FOR ROTATION AND MOMENTUM TRANSPORT SESSIONS

1. DISCUSSION OF ISSUES, OPPORTUNITIES AND CONCLUSIONS FOR ROTATION AND MOMENTUM TRANSPORT SESSIONS 10th ITPA Transport Physics and CDBM TG Meetings Princeton Plasma Physics Laboratory New Jersey, USA April 24-27, 2006

2. SUGGESTIONS/IMPROVEMENTS FOR JOINT EXPERIMENTS • General issues which need to be incorporated/addressed: • Effect of error fields needs input, e.g. R. Buttery, R. LaHaye, J. Menard, theory… • Do not want to regenerate error field scaling DB in another form! Need to know magnitudes to avoid confusion. • Same people can also cover NTM effects • Stochastic edge experiments relevant? TEXTOR, DIII-D: how to fit in? • Er/rotation modification by core *AE activity? Add flag to declare H or DB modes? • Connection to pedestal/SOL studies, often key region – set boundary constraints for core study: identify experts interested in contributing? • First task is to identify leaders of each topic.

3. SUGGESTIONS/IMPROVEMENTS FOR JOINT EXPERIMENTS • TP-6.1, spontaneous rotation • Explore incorporation of TCV in CMOD/DIII-D similarity experiment (main longer term goal) • Contact: Scarabosio/Bortolon/Sauter? • Distinguish potential effects, e.g. RF, ion loss, density profile,… - include flags/info in data base; include Er where measured. • Construction of scalar database needs data from JET, TS, TCV. AUG, MAST data also relevant – clear selection criteria, such as requiring H-mode/enhanced confinement. • Utilize ITPA scalar H-mode database? Additional parameters? • Should be joint with TP-6.3? – ways to share data among TP-6’s first? Add documentation to define data clearly. • Need profile data for modeling? – work with the ITPA profile database; identify smaller number of candidate shots for this. • IAEA submission by J. Rice provides clear focus for collaboration (if accepted): John will send info around as it becomes available, based only on published data now, but will be extended for IAEA. • Provide link to extract spontaneous rotation info from broader database that includes driven rotation, after identifying cases with substantial spontaneous rotation in driven rotation cases.

4. SUGGESTIONS/IMPROVEMENTS FOR JOINT EXPERIMENTS, CONTINUED • TP-6.2 • DIII-D strong possibility for FY 2007, JT-60U possible for 2006. Need one experiment to take lead – which? • TCV, JET to join? – to match joint experiment conditions?

5. SUGGESTIONS/IMPROVEMENTS FOR JOINT EXPERIMENTS, CONTINUED • TP-6.3 • Better to focus on standard regime, and exclude ITB discharges? – allow both regimes with clear flags? • TEXTOR L-mode database relevant? • What is the new joint experiments? Specify detail of needed data for existing comparison experiments, start with DIII-D and NSTX • Need definition of parameters needed: • Compare to current ITPA scalar H-mode DB parameters, and determine what would be new. Should be joint with TP-6.1? • Need profile data for modeling? Utilze ITPA profile DB - many discharges already there with torque info from transp, need to add momentum profile.

6. OTHER EXPERIMENTAL ASPECTS/COLLABORATIONS • Possible experimental tests of diffusive/non-diffusive character for momentum transport • Response to perturbations, NBI heat and momentum (trapped ion radial current at birth) pulses? ECH more localized pulses? Examine decay from transient conditions. • Explore possible link of TCV rotation changes to turbulence mode changes (existing AUG, DIII-D collaboration under TP-7) • Explore with TCV

7. MODELING/THEORY WORK • Most modeling efforts (predictive and interpretive) use NC theory to calculate poloidal rotation and ExB shearing rates. DIII-D, JET results indicate NC theory does not agree with measurements • Need to quantify potential impact on modeling - usually small, but may be important with balanced beams • E.g., JET using measured V-pol in Weiland’s calculation showed ITB formation; preliminary work needs extending • Resolve discrepancy between theory and measurement • Need to utilize models and simulations to identify key experimental tests, parameters to vary, etc. • Provide guidance for experiments and DB studies • Develop specific list of potential scans • E.g., nonlinear freq up-shift of turbulence

8. CREATE ONGOING WORKING GROUP? • Is there a need/desire to officially charter ongoing working group? • Depends on willingness to perform joint work on key issues • Work primarily via email, taking advantage of any overlap in attendance at meetings for discussions • e.g. “Rotation and Momentum Transport Working Group” (RMTWG) • Membership: extend invitation to selected key persons who could not attend • Need to generate an official charter to define role (~2 month, Ed Doyle draft) • Leadership: single or joint: John Rice • Set goals for progress by next meeting: • Update on spontaneous rotation scaling at IAEA (Rice) • Make initial contact/address issues listed earlier • CMOD/DIII-D similarity experiment performed • Generate DIII-D/NSTX joint experiment conditions • Progress on DB construction/first test – define driven rotation additions, scalar and profile?

9. Main Conclusions from Sessions