Interaction between NTMs and non-local transport in HL-2A

Slides:

Advertisements

Similar presentations

Statistical Properties of Broadband Magnetic Turbulence in the Reversed Field Pinch John Sarff D. Craig, L. Frassinetti 1, L. Marrelli 1, P. Martin 1,

Advertisements

Short wavelength ion temperature gradient driven instability in toroidal plasmas Zhe Gao, a) H. Sanuki, b) K. Itoh b) and J. Q. Dong c) a) Department of.

ASIPP Characteristics of edge localized modes in the superconducting tokamak EAST M. Jiang Institute of Plasma Physics Chinese Academy of Sciences The.

Institute of Interfacial Process Engineering and Plasma Technology Gas-puff imaging of blob filaments at ASDEX Upgrade TTF Workshop.

1 15th May 2012 Association EURATOM-CEA Shaodong Song Observation of Strong Inward Heat Transport with Off-axis ECRH in Tore Supra Heat pinch experiments.

1 Association Euratom-CEA TORE SUPRA EAST, China 7 th Jan 2010 X.L. Zou Observation of Strong Inward Heat Transport In Tore Supra with Off-Axis ECRH S.D.

A. Kirk, 20th IAEA Fusion Energy Conference, Vilamoura, Portugal, 2004 The structure of ELMS and the distribution of transient power loads in MAST Presented.

INTRODUCTION OF WAVE-PARTICLE RESONANCE IN TOKAMAKS J.Q. Dong Southwestern Institute of Physics Chengdu, China International School on Plasma Turbulence.

Momentum transport and flow shear suppression of turbulence in tokamaks Michael Barnes University of Oxford Culham Centre for Fusion Energy Michael Barnes.

New Experimental Results Obtained using Microwave Reflectometry in HL-2A Tokamak W.W. Xiao1), X.T. Ding1), X.L. Zou2), Z.T. Liu1), Y.D. Gao1), J.Q. Dong1),

1 Global Gyrokinetic Simulations of Toroidal ETG Mode in Reversed Shear Tokamaks Y. Idomura, S. Tokuda, and Y. Kishimoto Y. Idomura 1), S. Tokuda 1), and.

Large-scale structures in gyrofluid ETG/ITG turbulence and ion/electron transport 20 th IAEA Fusion Energy Conference, Vilamoura, Portugal, November.

SUMMARY OF EXPERIMENTAL CORE TURBULENCE CHARACTERISTICS IN OH AND ECRH T-10 TOKAMAK PLASMAS V. Vershkov, L.G. Eliseev, S.A. Grashin. A.V. Melnikov, D.A.

1 / 12 Association EURATOM-CEA IAEA 20th Fusion Energy Conference presented by Ph. Ghendrih S. Benkadda, P. Beyer M. Bécoulet, G. Falchetto,

D. Borba 1 21 st IAEA Fusion Energy Conference, Chengdu China 21 st October 2006 Excitation of Alfvén eigenmodes with sub-Alfvénic neutral beam ions in.

Parallel and Poloidal Sheared Flows close to Instability Threshold in the TJ-II Stellarator M. A. Pedrosa, C. Hidalgo, B. Gonçalves*, E. Ascasibar, T.

6 th Japan-Korea Workshop on Theory and Simulation of Magnetic Fusion Plasmas Hyunsun Han, G. Park, Sumin Yi, and J.Y. Kim 3D MHD SIMULATIONS.

TOTAL Simulation of ITER Plasmas Kozo YAMAZAKI Nagoya Univ., Chikusa-ku, Nagoya , Japan 1.

Edge Localized Modes propagation and fluctuations in the JET SOL region presented by Bruno Gonçalves EURATOM/IST, Portugal.

Excitation of ion temperature gradient and trapped electron modes in HL-2A tokamak The 3 th Annual Workshop on Fusion Simulation and Theory, Hefei, March.

11 Role of Non-resonant Modes in Zonal Flows and Intrinsic Rotation Generation Role of Non-resonant Modes in Zonal Flows and Intrinsic Rotation Generation.

Dynamics of ITG driven turbulence in the presence of a large spatial scale vortex flow Zheng-Xiong Wang, 1 J. Q. Li, 1 J. Q. Dong, 2 and Y. Kishimoto 1.

Contribution of KIT to LHD Topics from collaboration research on MHD phenomena in LHD S. Masamune, K.Y. Watanabe 1), S. Sakakibara 1), Y. Takemura, KIT.

Transport in three-dimensional magnetic field: examples from JT-60U and LHD Katsumi Ida and LHD experiment group and JT-60 group 14th IEA-RFP Workshop.

Lecture Series in Energetic Particle Physics of Fusion Plasmas Guoyong Fu Princeton Plasma Physics Laboratory Princeton University Princeton, NJ 08543,

HL-2A Jiaqi Dong Southwestern Institute of Physics & Institute for Fusion Theory and Simulation, ZJU International West Lake Workshop on Fusion Theory.

HT-7 ASIPP The Influence of Neutral Particles on Edge Turbulence and Confinement in the HT-7 Tokamak Mei Song, B. N. Wan, G. S. Xu, B. L. Ling, C. F. Li.

U NIVERSITY OF S CIENCE AND T ECHNOLOGY OF C HINA CAS K EY L ABORATORY OF B ASIC P LASMA P HYSICS Recent experimental results of zonal flows in edge tokamak.

STUDIES OF NONLINEAR RESISTIVE AND EXTENDED MHD IN ADVANCED TOKAMAKS USING THE NIMROD CODE D. D. Schnack*, T. A. Gianakon**, S. E. Kruger*, and A. Tarditi*

Active Control of MHDinstabilitiy 2002/11/19 S.Ohdachi et.al. Sawtooth-like phenomena in LHD S. Ohdachi, S.Yamamoto, K. Toi, K. Y.Watanabe, S.Sakakibara,

TEC Trilateral Euregio Cluster Institut für PlasmaphysikAssoziation EURATOM-Forschungszentrum Jülich 21st IAEA Fusion Energy Conference, October.

1 L.W. Yan, Overview on HL-2A, 23rd IAEA FEC, Oct. 2010, Daejeon, Republic of Korea HL-2A 2 nd Asia-Pacific Transport Working Group Meeting ELM mitigation.

MCZ Active MHD Control Needs in Helical Configurations M.C. Zarnstorff 1 Presented by E. Fredrickson 1 With thanks to A. Weller 2, J. Geiger 2,

1 LHCD Properties with a New Lower Hybrid Wave Antenna on HT-7 Tokamak Wei Wei,Guangli Kuang,Bojiang Ding,Weici Shen and HT-7 Team Institute of Plasma.

Integrated Simulation of ELM Energy Loss Determined by Pedestal MHD and SOL Transport N. Hayashi, T. Takizuka, T. Ozeki, N. Aiba, N. Oyama JAEA Naka TH/4-2.

Association Euratom-CEA TORE SUPRA EAST, China 07/01/2010Xiaolan Zou1 Xiaolan ZOU CEA, IRFM, F Saint-Paul-Lez-Durance, France Heat and Particle Transport.

Role of thermal instabilities and anomalous transport in the density limit M.Z.Tokar, F.A.Kelly, Y.Liang, X.Loozen Institut für Plasmaphysik, Forschungszentrum.

Distributions of plasma parameters and observation of intermittency in edge plasma of SUNIST W H Wang, Y X He, and SUNIST Team Department of Engineering.

Y. Kishimoto 1,2), K. Miki 1), N. Miyato 2), J.Q.Li 1), J. Anderson 1) 21 st IAEA Fusion Energy Conference IAEA-CN-149-PD2 (Post deadline paper) October.

Neoclassical Effects in the Theory of Magnetic Islands: Neoclassical Tearing Modes and more A. Smolyakov* University of Saskatchewan, Saskatoon, Canada,

Helically Symmetry Configuration Evidence for Alfvénic Fluctuations in Quasi-Helically Symmetric HSX Plasmas C. Deng and D.L. Brower, University of California,

Simulation of Turbulence in FTU M. Romanelli, M De Benedetti, A Thyagaraja* *UKAEA, Culham Sciance Centre, UK Associazione.

1 ASIPP Sawtooth Stabilization by Barely Trapped Energetic Electrons Produced by ECRH Zhou Deng, Wang Shaojie, Zhang Cheng Institute of Plasma Physics,

IAEA-TM 02/03/2005 1G. Falchetto DRFC, CEA-Cadarache Association EURATOM-CEA NON-LINEAR FLUID SIMULATIONS of THE EFFECT of ROTATION on ION HEAT TURBULENT.

Energetic Particles Interaction with the Non-resonant Internal Kink in Spherical Tokamaks Feng Wang*, G.Y. Fu**, J.A. Breslau**, E.D. Fredrickson**, J.Y.

Interaction between vortex flow and microturbulence Zheng-Xiong Wang （王正汹） Dalian University of Technology, Dalian, China West Lake International Symposium.

HT-7 Proposal of the investigation on the m=1 mode oscillations in LHCD Plasmas on HT-7 Exp2005 ASIPP Youwen Sun, Baonian Wan and the MHD Team Institute.

TH/7-1Multi-phase Simulation of Alfvén Eigenmodes and Fast Ion Distribution Flattening in DIII-D Experiment Y. Todo (NIFS, SOKENDAI) M. A. Van Zeeland.

Energetic ion excited long-lasting “sword” modes in tokamak plasmas with low magnetic shear Speaker:RuiBin Zhang Advisor:Xiaogang Wang School of Physics,

Profiles of density fluctuations in frequency range of (20-110)kHz Core density fluctuations Parallel flow measured by CHERS Core Density Fluctuations.

Towards an Emerging Understanding of Nonlocal Transport K.Ida 1), Z.Shi 2), H.J.Sun 2,3), S.Inagaki 4), K.Kamiya 5), J.Rice 6), N.Tamura 1), P.H.Diamond.

G.Y. Park 1, S.S. Kim 1, T. Rhee 1, H.G. Jhang 1, P.H. Diamond 1,2, I. Cziegler 2, G. Tynan 2, and X.Q. Xu 3 1 National Fusion Research Institute, Korea.

U NIVERSITY OF S CIENCE AND T ECHNOLOGY OF C HINA Influence of ion orbit width on threshold of neoclassical tearing modes Huishan Cai 1, Ding Li 2, Jintao.

Neoclassical Predictions of ‘Electron Root’ Plasmas at HSX

Ryan Woodard (Univ. of Alaska - Fairbanks)

25th IAEA FUSION ENERGY CONFERENCE EX/11-3

Recycling and impurity retention in high-density,

Presented by: Chen Wei1 (陈伟)

Reduction of ELM energy loss by pellet injection for ELM pacing

L-H power threshold and ELM control techniques: experiments on MAST and JET Carlos Hidalgo EURATOM-CIEMAT Acknowledgments to: A. Kirk (MAST) European.

2/13 Introduction Knowledge of the influence of the hydrogen isotope on H-mode confinement is essential for accurately projecting the energy confinement.

Investigation of triggering mechanisms for internal transport barriers in Alcator C-Mod K. Zhurovich C. Fiore, D. Ernst, P. Bonoli, M. Greenwald, A. Hubbard,

Influence of energetic ions on neoclassical tearing modes

T. Morisaki1,3 and the LHD Experiment Group

Stabilization of m/n=1/1 fishbone by ECRH

20th IAEA Fusion Energy Conference,

T. Morisaki1,3 and the LHD Experiment Group

H. Nakano1,3, S. Murakami5, K. Ida1,3, M. Yoshinuma1,3, S. Ohdachi1,3,

No ELM, Small ELM and Large ELM Strawman Scenarios

Presentation transcript:

Interaction between NTMs and non-local transport in HL-2A 25th IAEA FUSION ENERGY CONFERENCE EX/6-4 Interaction between NTMs and non-local transport in HL-2A X. Q. Ji 1 On behalf of: Y. Xu1, Yi Liu1, O. Pan1, Q. W. Yang1, Z. B. Shi1, B. B. Feng1, W, Chen1, C. Y. Chen1, Z. X. Wang2, L. Wei2, M. Jiang1, W. L. Zhong1, Yuan Xu1, T. F. Sun1, Y. B. Dong1, Y. Zhou1, W. Deng1, B. S. Yuan1, X. R. Duan1, Liu Yong1 and the HL-2A team 1 Southwestern Institute of Physics, Chengdu 610041 China 2 Dalian University of Technology, Dalian 116024 China

Outline Motivation Non-local transport Non-local transport in HL-2A Enhanced avalanche characteristics during non-local transport NTM onset during non-local transport Typical feature of NTM onset during non-local transport Relation between NTM onset and non-local transport Impact of NTM on non-local transport Damping effects of NTM on non-local transport Reduction of avalanche feature with NTM in non-locality Summary

Motivation What is the mechanism of non-local transport ? Non-local transport has been observed in many fusion devices. TEXT-U /TFTR /RTP /JET /TORE-SUPRA /HL-2A / LHD… K W Gentle, PRL1995 Non-local transport: Long-distance-correlated events with reversed polarity. Possible mechanisms: J. Callen, PPCF 1997, B173 i) Empirical model, ii) marginal stability, iii) self-organized criticality (SOC)? What is the mechanism of NTM onset ? NTM effects  β limitation or major disruption NTM onset: Seeding process? Threshold? [dw/dt ~ (w), BS, GGJ, pol, CD] What is the possible link between NTM and non-local transport ? In HL-2A, NTM onset during non-locality was observed for the first time.

Outline Motivation Non-local transport Non-local transport in HL-2A Enhanced avalanche characteristics during non-local transport NTM onset during non-local transport Typical feature of NTM onset during non-local transport Relation between NTM onset and non-local transport Impact of NTM on non-local transport Damping effects of NTM on non-local transport Reduction of avalanche feature with NTM in non-locality Summary

Non-local transport in HL-2A After each SMBI (Supersonic Molecular Beam Injection), edge Te reduces by cooling whereas the core Te quickly rises over long-distance  non-local transport ! This non-locality usually occurs (i) in low density (<ne> < 2.0 ×1019m-3) ohmic or ECRH heating plasmas; (ii) very transient process ~ (15-30) ms Reversion surface of Te perturbation is normally outside q=1

Non-local transport: long-range radial propagation Edge Inward heat flux propagation observed in low-frequency range (f ~ 200 Hz) of Te fluctuations Core Further analysis of cross-correlation in temperature fluctuation signals show clearly a long range radial propagation of heat flux from the plasma edge to the core, as shown in this figure. So, what are the mechanisms behind this transport phenomenon? As I said before, these are several candidates to explain it. First one is empirical models, which added addition heat diffusivity coefficient. The marginal stability models proposed critical parameters determining the system states. The last one is so-called self-organized-criticality. This SOC linked to avalanche transport events. The f-1 dependence, long self-similarity, large values of Hurst parameters, and so on …… Because the first two are modeling work, which are difficult for us to judge, for the last one, we can check our data with SOC properties. What are the mechanisms behind ? Empirical model (added diffusion/ heat coefficients) Marginal stability (propose critical parameters determining system states) SOC (avalanche, f 1 dependence, self-similarity /large Hurst exponent……)

Typical characteristics of SOC behavior SF (structure function) R/S (rescaled range) Inward Outward f--1 dependence in Intermediate range (3-30 kHz)  overlapping of avalanche transport. long tail in autocorrelation function (ACF)  long time correlated events. Large value of Hurst parameter estimated by R/S and SF  indication of “self-similarity”. Dual propagation of avalanche events  a signature of SOC system !

Enhanced avalanche characteristics during non-local transport (I) SMBI During Before w non-locality w/o non-locality w w/o During non-local transport, the time lag in ACF and Hurst parameters are all larger than those before non-locality, revealing an enhanced avalanche behavior in the non-local transport.

Enhanced avalanche characteristics during non-local transport (II) Before non-local transport During non-local transport Correlation length of radial propagation events mostly increase during non-locality. Count number of radial correlation length for avalanche propagation events with/without non-locality It appears that the SOC regime could be responsible for the non-local transport at HL-2A

Outline Motivation Non-local transport Non-local transport in HL-2A Enhanced avalanche characteristics during non-local transport NTM onset during non-local transport Typical feature of NTM onset during non-local transport Relation between NTM onset and non-local transport Impact of NTM on non-local transport Damping effects of NTM on non-local transport Reduction of avalanche feature with NTM in non-locality Summary

Typical feature of NTM onset during non-local transport At high PECR H(high β), a 3/2 NTM mode is triggered during non-local transport Note: NTM driven by the transient Te perturbation during non-local transport is observed for the first time !

Another example of NTMs triggered by gas-puffing

Experimental evidence of NTM modes Noisy level Island width w  (Br)1/2 displays linear dependence on βN Saturated island width quickly drops on a time scale of ~10 ms after ECRH turn off

Outline Motivation Non-local transport Non-local transport in HL-2A Enhanced avalanche characteristics during non-local transport NTM onset during non-local transport Typical feature of NTM onset during non-local transport Relation between NTM onset and non-local transport Impact of NTM on non-local transport Damping effects of NTM on non-local transport Reduction of avalanche feature with NTM in non-locality Summary

Relation between NTM onset and non-local transport reversion surface at  =0.46 Te (a.u) Contour-plot of frequency spectrum of Te fluctuations at  =0.46 NTM onset location  at the reversion surface of non-locality NTM onset time  at the maximum changes in Te gradient

Relation between NTM onset and Non-local transport Te = Te,3/2 NTM Te,SMBI/gas-puffing Solid circles indicate location of q=3/2 surfaces The 3/2 NTMs are located near the inversion surface of electron temperature perturbation. dTe/dr: Te gradient of two radial loci around ρinv Δt = t -tSMBI/gas-puffing Solid circles mark onset time of 3/2 NTM 3/2 NTMs onset when the local electron temperature gradient nearly reaches to the maximum value.

Spontaneous onset of NTMs during non-local transport Typical island growth of a NTM with Δ’ < 0 Seeding process Threshold Spontaneous NTM: no MHD activity was found as seeding island. ▽P grows strong enough (by non-locality) to linearly drive NTMs.

Critical value of βN for NTM onset With non-locality, the critical value of N for NTM onset is reduced. Possible mechanism for lower N in non-local transport to trigger the NTM is due to enhanced local P (BS) around the reversion surface.

Outline Motivation Non-local transport Non-local transport in HL-2A Enhanced avalanche characteristics during non-local transport NTM onset during non-local transport Typical feature of NTM onset during non-local transport Relation between NTM onset and non-local transport Impact of NTM on non-local transport Damping effects of NTM on non-local transport Reduction of avalanche feature with NTM in non-locality Summary

Damping effect of NTM on non-local transport The NTMs impose damping effects on non-local transport. Why ?

Reduction of avalanche feature with NTM in non-locality Without NTM during non-locality Non-local transport Non-local transport + NTM 3/2 NTM With NTM during non-locality With NTMs, Hurst exponents decrease with weakened SOC dynamics in the core. Avalanche propagation is blocked near the NTM surface of island, where enhanced flow shear around rational surface may suppress avalanche

Summary In HL-2A, we observed NTM onset during non-locality for the first time. During non-locality, avalanche characteristics are enhanced, suggesting that the SOC regime could be responsible for non-local transport in HL-2A. Possible link between non-locality and NTMs has been identified: (i) the local increase of Te nearby reversion surface of non-locality  enhanced P (BS)  onset of NTMs (ii) no seeding island was observed, indicating that ▽P grows strong enough (by non-locality) to linearly drive NTMs. (iii) Avalanche propagation is blocked nearby the NTM surface of island  SOC dynamics of non-locality are weakened  nonlocal transport is damped by NTM onset.

Thanks for your attention! 25th IAEA FUSION ENERGY CONFERENCE EX/6-4 Thanks for your attention!

Modified Rutherford Equation Typical island growth of a NTM with Δ’ < 0 Seeding process Threshold

Different reference channels Ref: r/a=0.01 Ref: r/a=0.16 Ref: r/a=0.31 Ref: r/a=0.51 Ref: r/a=0.69 Ref: r/a=0.80

Different filter bandwidth During non-local 5-6kHz 5.2-5.8kHz 4.5-6.5kHz

Bicoherence of Te and B