1. b Scaling experiments in ASADEX Upgrade F. Ryter

1. 10th Meeting of the ITPA CDBM TG, PPPL, 24-27 APR. 2006 Summary of “Progress on ITPA/IEA Joint Experiments” Mon. 24 Apr 13:00-15:00, room LSB318 T. Takizuka (JAEA) 1. b Scaling experiments in ASADEX Upgrade F. Ryter First attempts for dedicated b scaling were performed on Jan-Mar 2006. Low b (bN=1.4) and High b (bN=2) were compared. Global analysis shows very strong b degradation. Results are preliminary. Further experiments are foreseen. 2. Proposed JET 2006 confinement experiments D.C. McDonald Hybrid studies for the hybrid confinement scaling r* scaling CDB8 JET/DIII-D/AUG/C-Mod (May-Jun 2006) n* scan ; nonlinear n* dependence of tE, particle and impurity transport (peaking at low n*), ELM energy loss increasing at low n* 3. L-mode b-scaling experiments in Tore-Supra A. Sirinelli (F. Imbeaux) Weak b-scaling (tE ~ b-0.3, c ~ b0.4) is found

2. Status of Contributions to CDB-2: Nov proposal, Jan, AprilConfinement scaling in ELMy H-modes: b degradation)Spokesperson: C.C. Petty JET: Experiments planned for a hybrid-like scenario in early 2006. AUG: Experiments foreseen in 2006. JT-60U: Experiments done, no new experiments in 2005. Journal paper in review. MAST: Experiments planned for 2005/6, subject to NBI availability. NSTX: Experiments planned for 2006 if operation at higher field is allowed. TS: L-mode experiments with ICRH & LH scheduled for November 2005. Electron density and temperature fluctuations will be measured with 3 reflectometers and ECE. JET, AUG, DIII-D: Examine whether weaker upper triangularity in H-mode discharges is responsible for the beta dependence? JET: Extend experiments to higher b, plans for d effect will be discussed at CDBM meeting at PPPL in April. AUG: b scaling experiments to be done in early 2006, but not d dependence. DIII-D: not doing this year, but on the  extended list for future work. AUG: Planed experiments have been started in (January - March) and will be continued till the end of 2006 MAST: Experiments planned for 2006 TS: L-mode experiments Done NSTX: Experiments planned for 2006

3. Status of Contributions to CDB-4: Nov proposal, Jan, AprilConfinement scaling in ELMy H-modes: n* scans at fixed n/nGSpokesperson: J. Snipes C-Mod: MP392 was approved for these experiments, and is expected to be scheduled in late 2005 or 2006. DIII-D: experiments may be attempted in 2006. AUG: await the outcome of PEP-7 (the pedestal identity experiment) and to assess afterwards if identity of n* versus identity of n/nG can be separated given the error-bars - such experiments would not be done before 2007. DIII-D: not doing this year, but on the extended list for future work. C-Mod: Experiment now expected in 2006.

4. Status of Contributions to CDB-6: Nov proposal, Jan, AprilImproving the condition of Global DBs: Low ASpokesperson: S. Kaye MAST/NSTX: Identity experiments to confirm parametric confinement scalings at low A and understand the scaling of confinement with A by connecting to data from conventional and higher A tokamaks. • Establish the scaling of confinement with both toroidal beta and collisionality in L and H-mode discharges. • Eliminate the strong correlation between b and e in the database (low aspect ratio devices operate at high b). • Improve the condition of the database by the addition of low-b low A data, and low BT, high b data at conventional A. DIII-D/NSTX: Similarity experiment will focus on ensuring a similar fast ion fraction in the comparison discharges. The devices will individually perform a r* scan to determine scaling with toroidal r*. DIII-D, NSTX: not doing this year, but on the extended list for future work.

5. Status of Contributions to CDB-8: Nov proposal, Jan,Aprilr* scaling along an ITER relevant path at both high and low bSpokesperson: D. McDonald JET/C-Mod: These devices lie at the extremes of r*, and will perform the low b experiments in February and March 2006, respectively. AUG/DIII-D: The high b part of the r* scan would be a hybrid scenario, which will be deferred until JET auxiliary power is increased and the ‘hybrid’ scenario is more firmly established. JET: Experiments scheduled for June C-Mod: Experiments scheduled for May (need ICRF running well) DIII-D: Experiments with ITER shape scheduled for June

6. Status of Contributions to CDB-9: Nov proposal, Jan,AprilDensity profiles at low collisionalitySpokesperson: H. Weisen JET, JT-60U, AUG, DIII-D : Target conditions Ti/Te~1 and neff<0.2 at r/a~0.5 at moderate bN~1.8, may require adjusting the heating because of poor equipartition at low n. All: Provide scans to lowest achievable n even if the lowest target value (neff<0.2) cannot be achieved. Profiles of impurities should be examined in all cases. JET: Experiments at low n with pellet injection ~June 2006 when injector is available. Notes: Experimental scans may be designed to also cover the information for CDB-4 (n scan at fixed n/nG), and TP-3.1 (Ti/Te effects on confinement in hybrid scenarios) and SSO/TP-2.1 (hybrid regime development). JET: Experiments planned for March & May 2006 on particle and impurity transport at low n as part of pre-existing proposals - not driven by Te~Ti. JT-60U: Experiments planned for 2006. Te~Ti may  be too restrictive. AUG: Most effort on analysis of existing data and collaboration with JET. DIII-D: Not doing this year, but on the  extended list for future work. Notes: Primary collaboration for this year is between JET (Weisen) and AUG (Angioni). Retain as P (programmatic) designation for this year. AUG: Experiments on peaking at low n planned for late June (post EPS) C-Mod: Snipes working with Weisen to define experiments for 2006 JET: experiments planned for June and July 2006 (purpose shear dependence at low n* and effect of electron heating in H-mode)