Yves Martin Centre de Recherches en Physique des Plasmas Association Euratom - Confédération Suisse Ecole Polytechnique Fédérale de Lausanne (EPFL) CH Lausanne, Switzerland ITPA – CDBM H-mode threshold database Threshold database status October Naka

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 2 Action list decided in Lausanne, May 2007 New data JFT-2M, CHS (TT, done during the meeting) NSTX (SK, before next meeting) MAST (MV, tbd) Data check CMOD (JS, 30 June) Description of data selection criteria (YM, 31 May + next meeting) In the paper – tb discussed New version of DB data checked IGDBTH4v6c (asap, CMOD) New data: IGDBTH4v7 (before next meeting) done without MAST and NSTX Recommended scaling Estimation with changes in data selection (asap, data checked) Errors, Kadomtsev constraint (before next meeting)... tb discussed

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 3 Action list decided in Lausanne, May 2007, cntd Density dependence of threshold power Done in the paper Identify dedicated density scans in threshold DB (CMOD, done during meeting, others: 31 May) Not used in paper/not done Verify if experiments were done and not in threshold DB, then provide data (All, 30 June) Status? Density at minimum threshold power Joint experiment proposed (CDB-10) DB analysis done for the paper Power ratio (P L /P thresh ) in good confinement regimes Identify published good confinement results which are not included in the confinement DB (All, 30 June) and provide data Extract evolution of power ratio for a few typical discharges (All, 15 August) Search for evolution of power ratio in ITER scenarios (YM, 30 June)... tb discussed

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 4 Action status – New data No new data sent from MAST, NSTX Action ? Continue waiting Stop waiting Waiting: NSTXSK? MASTMV?

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 5 Action status – recommended scaling... New version of the database released on IGDBTH4v7 Contains: new data from CHS & JFT2M, corrected CMOD data and selection parameter (SELEC2007) Corrected version on Selection criteria  Phase=LDL removed for AUG  Phase=D removed CMOD Checking DB: code to select any tiny change between two versions  Issue of format Recommended scaling In paper... tb discussed Density dependence, minimum threshold power, PL/PThresh,... In paper... tb discussed

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 6 Sensitivity study Received from R.Stambaugh, June 12th: You are requested by the ITER Design Review Working Group #1, Design Requirements and Physics Objectives, to perform the task described as input to the ITER Design Review. Part of the DR&PO Working Group's Task 2, Sensitivity Studies Impact on ITER performance objectives of operating at 10% lower toroidal field Received a spreadsheet with data corresponding with variants of the ITER standard scenarios at -10% toroidal field. Also included: variants which recover full performance by lowering little q, raising density, raising confinement H, raising stability (betaN), or raising elongation at full minor radius

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 7 Sensitivity study: Tasks Task 2.1. Spreadsheet Scalings from the Baseline Scenarios Task 2.2 Scenario Variation Assessments Using Calibrated 1-D Transport Models. Task 2.3. Scenario Variation Assessments Using 1-D Codes With First Principles Transport Models. Task 2.4. Operating Space Diagrams Task 2.5. Projections of Advanced Operating Modes from Current Experiments. Task 2.6. Secondary and More Detailed Consequences of Scenario Variations L-H Transition Threshold Power Impact on NNBI voltage and/or shinethrough issues ITER-IO Impact on ICRF application Impact on ECH/ECCD application, including NTM situation Risk of operating at lower q to recover fusion power Density limit and confinement at high densities General shift to higher required bN to recover fusion power as BT is reduced, with attendant increased need for wall stabilization AE mode behavior ITER support toward DEMO, including power handling issues, steady-state, etc Impact on TBM program

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 8 Sensitivity study: report Introduction Influence of the main toroidal field reduction Reduction of the threshold power (from ~90MW to ~80MW at m -3 ) Sensitivity around reduced field reference Raise plasma current: low q95 values, difficult to quantify, selection criteria to avoid low q95, ITER: at q95=2.8, threshold might increase Increase H98y2 with reduced power: difficult to achieve Increase density: Increase in threshold power but still lower than original scenario Increase elongation: increased threshold power if q95 and Greenwald fraction maintained Decrease T, ,external power: difficult to achieve General comment on ITER threshold power at high density Threshold power 2-3 larger than indicated in Table and larger than available power (hysteresis, PL/Pthresh, density of minimum threshold,...)

Yves Martin, ITPA TG CDBM LH Transitions, October 2007, Naka 9 Talks Scaling of the L-H Transition at Low Density in C-Mod A. Hubbard (J. Snipes) Validation of DIII-D H_98y2 factor in Power Threshold Database J. Deboo (G. Wang) Sensitivity of L-H power threshold to rotation in DIII-D (given yesterday) P.Gohil Address Mukhovatov questions on ITER guidelines Reports of data submissions, analyses, discussion of IAEA H-mode Meeting paper, etc