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Summary of Modelling WG/Joint Sessions – 1 W.A. Houlberg. Mon – Joint PEP/TP/CDBM sessions on momentum transport … Kamada: Rotation affects many aspects of operation, with increasing impact as we go from standard operation to hybrid to steady-state Critical question: Can we control rotation?
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Summary of Modelling WG/Joint Sessions – 1W.A. Houlberg • Mon – Joint PEP/TP/CDBM sessions on momentum transport … • Kamada: Rotation affects many aspects of operation, with increasing impact as we go from standard operation to hybrid to steady-state • Critical question: Can we control rotation? • Processes determining V(r) need to be separately evaluated, because there is evidence for intrinsic (spontaneous) rotation from core and edge and a momentum pinch in addition to ‘diffusive’ and pinch responses to external drive • Yoshida, de Vries, Kaye: Characteristics of rotation profile, momentum transport and correlations with thermal transport in JT-60U, JET, NSTX • Gohil: Lower L-H threshold with reduced torque in DIII-D • Urano: Confinement improves with co-injection in JT-60U H-mode • Rice: Observations of intrinsic rotation from database, projection to ITER • Hahm: Theory basis of diffusive and non-diffusive momentum transport • Mukhovatov, Sakamoto: ITER projections; Rice prediction gives intrinsic rotation 3-4 times higher than from 2 NBI injectors • Discussion: Need to assess full profiles – edge and core aspects differ, evaluate shear as well as rotation velocity 13th ITPA CDBM Meeting, Naka 1-3 October 2007
Summary of Modelling WG/Joint Sessions – 2W.A. Houlberg • Tue – Joint PEP/CDBM Modelling on Pedestal Modelling, ITER Predictions • Bateman: • CPES project (led by C.S. Chang) coupling advanced edge physics codes (e.g., kinetic treatment of transport, 3-D MHD stability) to study barriers, ELMs. • Promising initial results, but still lack quantified comparison with experiments • Snyder: • Pedestal height in Type I ELMy H-mode is governed by intermediate n MHD modes (peeling-ballooning) • DB indicates pedestal height & width increase with power • Power dependence is a proxy for other variables height increase • Pedestal width does not appear to scale with global p or beta-p, but does appear to scale with local pedestal T or p – strong dependence required to explain data • Possible that rotation is important at lower power and width • Future: more quantitative models based on ExB stabilization of turbulence 13th ITPA CDBM Meeting, Naka 1-3 October 2007