Presentation on theme: "Current status of H-mode/pedestal related experiments in JT-60U 14th meeting of the ITPA-TG on Pedestal&Edge Physics Group, General Atomics, April 29-May."— Presentation transcript:
Current status of H-mode/pedestal related experiments in JT-60U 14th meeting of the ITPA-TG on Pedestal&Edge Physics Group, General Atomics, April 29-May 2, 2008 N. Oyama and the JT-60 Team JAEA Naka
Important notice Our Director General (Dr. Tsunematsu) of Naka Fusion institute has officially announced that JAEA decided to shut down JT-60U in August in 2008. The physics experiments will be 11 weeks (43 days) from May to August. So, the machine time is quite limited. However, we would like to promote inter- machine experiments to contribute ITPA and ITER activity as well as our original experiments. Your direct participation in inter-machine experiments are very welcome. (Last chance!)
Experimental schedule Current plan of H-mode & pedestal related experiments
New diagnostics (fast CXRS) Specifications Spatial resolution (spot size) : ~5 cm (Toroidal, 30ch) ~0.5 cm (Poloidal, 30ch) Time resolution: 2.5-5 ms (Previously 50 ms) Co-rotating plasma I p /B T = 1.66MA/3.2T P NBI ~ 6.4MW f ELM ~ 18Hz A B 8.94s
New diagnostics (Li-beam probe) Purpose Density and density fluctuation profiles T i and V p profiles as CXRS Current profile by Zeeman polarimetry Specifications Spatial resolution (dR): <10 mm Time resolution for j(r): 1-10 ms Frequency range for density fluctuation: <500kHz Beam duration: <60 s Current status Development of beam was finished. Beam axis alignment and adjustment of etalon filter are on going. Density profile measurement will be available from May A. Kojima, submitted to RSI
Objectives of pedestal research Making use of new edge diagnostics, following pedestal research will be conducted. Pedestal structure and H-mode confinement Effect of TF ripple, rotation, neutral penetration, current profile Inter ELM transport Dynamics and characteristics of type I ELM Precursor, affected area, recovery of transport barrier Propagation of ELM pulse in SOL and inside the top pedestal toward ITB Physics understanding of the role of plasma rotation Edge stability including measured edge current Small/no ELM regimes (grassy ELM and QH-mode) Physics understanding of the role of plasma rotation and e * Expansion of operational regime
PEP-1+3 JET/JT-60U ripple effects and rotation In 2005-2006 campaign, combination of tangential NBI was fixed To separate rotation effect, rotation scan experiments using JET/JT-60U similarity shape are proposed. N. Oyama, 11 th H-mode WS. Accepted for publication in JPCS.
PEP-13/17 grassy ELM experiments e * scan (toward higher than 1) by changing edge n e Target plasma is operated at high regime (both low and high q 95 regime) Rotation effect is also interested.
PEP-14 QH-mode experiments DIII-D CTR rotation K. Burrell, APS2007 JT-60U N. Oyama, NF45(2005)