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Steady State Operation & Energetic Particles. Advanced Scenario need the same development path as the reference ITER H-mode scenario Multi-machine experiments essential to develop common vocabulary and experience Progressive build-up of integration issues
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Steady State Operation & Energetic Particles • Advanced Scenario need the same development path as the reference ITER H-mode scenario • Multi-machine experiments essential to develop common vocabulary and experience • Progressive build-up of integration issues • Scenarios seems to depend upon current profile: • Hybrid Scenarios • Steady-State scenarios • At this stage proposals are generic since related to scenario operation development: • detailed proposals will be made by ROs following approval • Specific joint experiments on Energetic Particles not being made: • Joint data analysis is highly recommended
IEA-LT/ ITPA Collaboration : Hybrid Scenario • Definition: • The objective of the ITER Hybrid scenario is the maximum fluence/year(pulse). • High priority in 2003 • map the existence domain for each machine • identify across the domain the mechanism by which the current is prevented from peaking (fishbones, tearing mode, etc.). • Variations of performance (e.g., bt) with q95 density and shape at fixed field and shape are of high interest. ROs: E.Joffrin, G.Sips, M.Wade, A.Isayama (S.Wolfe)
Proposals for International Collaboration in 2004 • Hybrid scenario • Complete mapping existence domain • AUG may need more time on q95 scan.Older ASDEX Upgrade results already span a range of densities • DIIID needs more time on density scan; needs a little time for q95 scan • JET established scenario at q95= 4; mapping not started (Nov. 2003 but not in 2004) . • JT60 established scenario at q95 = 3.6; mapping not started (starting in Dec. 2003) • C-MOD:A proposal has been made to use new hardware (LHCD in particular) to access hybrid regime
Hybrid scenario (2) • Compare effects of tearing modes, fishbones, and sawteeth in this regime among machines • current profile broadening, • confinement reduction, • fast ion transport with fishbones, • fast ion effects on sawteeth) • This may not require additional run time immediately, but rather a coordinated analysis effort of the domain mapping discharges, which may lead to dedicated experiments. • Investigations of Te/Ti effect on confinement in hybrid scenarios • All machines have some capability to replace neutral beam power with ICRF or EC, which will heat the electrons.
IEA-LT/ ITPA Collaboration : Steady State Scenario • Definition: The objective of the ITER Steady state scenario is 100% non-inductive operation at Q>5. • Joint experiments to probe the performance limits are proposed with the following specifications on the q profile: q95=4-5, qmin = 2+-0.5, q(0) -qmin <0.5. Discharges with this profile have demonstrated N>3 and fBS>0.5 and are at present the most promising for ITER. • Experiments with other q profiles have realized fully non-inductive sustainment. • Candidate profiles for steady state should test consistency with Q>5 in burning plasma conditions.
Steady State Operation: Priorities in 2003 • High priority for the four large divertor machines • explore performance limits with the recommended q profile and compare the results. ROs: X.Litaudon, J.Hobirk, T.Luce, S.Ide, (A.Hubbard)
Proposals for International Collaboration in 2004 • Steady-state scenario • Document performance boundaries for the agreed current profile Performance includes the assessment of the potential for each machine to achieve fully non-inductive operation with that q profile • AUG: scenario has not been established • DIIID beta limit studies with variation in shape and pressure profiles has been done; • experiments with fully non-inductive operation still require time • JET: scenario to study performance limits (with present heating&CD capability) needs to be developed (unlikely in Dec.2003, not in 2004) • JT-60U: scenario was established in the past; to be re-established with modern diagnostics and heating systems (starting Dec. 2003, priorities being decided)
Steady State Scenario (ctd) • The key to pushing forward steady-state scenario is to have a demonstration of performance levels in JET or JT-60U which can be reasonably projected to burning plasmas. • Development of such a scenario is consistent with the JT-60U goals for 2004 • Other scenarios (different q profile, very hollow in particular) established on one machine to be tested in another machine (possible proposal from JT-60U) • Increase significantly collaboration between groups • will greatly enhance the probability of success