Influence of ECR Heating on NBI-driven Alfvén Eigenmodes in the TJ-II Stellarator

Size: px
Start display at page:

Download "Influence of ECR Heating on NBI-driven Alfvén Eigenmodes in the TJ-II Stellarator"

Transcription

1 EX/P- Influence of ECR Heating on NBI-driven Alfvén Eigenmodes in the TJ-II Stellarator Á. Cappa, F. Castejón, T. Estrada, J.M. Fontdecaba, M. Liniers and E. Ascasíbar Laboratorio Nacional de Fusión CIEMAT, Madrid, Spain Corresponding Author: Abstract: NBI driven Alfvén modes are found in several magnetic configurations of the TJ-II stellarator, allowing us to test any control knob able to suppress, or at least modify, the Alfvén activity of the device. In particular, the paper describes the effect of electron cyclotron resonance heating (ECRH) on the Alfvénic oscillations when different EC beam launching parameters are tested. The observed modes may exhibit steady or chirping behavior, as well as a strong reduction in amplitude, depending on the launching direction of each beam. Introduction Controlling the amplitude of Alfvén eigenmodes (AE s) in fusion plasmas is an open issue with paramount relevance for ITER and beyond, because the fast ion losses associated to these modes might be deleterious for plasma performance as well as destructive for the plasma facing components. The stabilization of the reversed shear Alfvén eigenmodes (RSAE s) using ECRH has been analyzed in detail in the DIII D tokamak [, ] and recently, first experiments in TJ-II [] have also demonstrated the ability of ECRH to mitigate and modify the amplitude and nature of the fast ion driven modes. The initial experiments carried out in TJ II explored the impact of ECRH within a limited range of launching configurations. The experiments presented in this paper describe in detail the dependence of the AE s properties on the power deposition location of both beams, the NBI parameters and the magnetic configuration. Previous experiments, documented in [] and related to density dependence or mode suppression, were repeated looking for the reproducibility of the results. TJ II stellarator and its heating systems TJ II stellarator is a four-period heliac-type stellarator with low magnetic shear and good MHD stability properties provided by magnetic well. The major and averaged plasma radius of the device are R =. m and a. m respectively. The central magnetic field strength is.9 T (at the toroidal locations of ECRH injection) and a wide range

2 EX/P- of central rotational transform.9 ι()/π. is achievable. The NBI heating system which consists of two injectors providing co and counter sub-alfvénic H beams (v beam /v A.. for line averaged densities around. 9 cm ) with currents up to A and with a maximum acceleration voltage of kv provide up to 7 kw portthrough power per injector. The experiments described in this paper were carried out using only the co-direction injector. Two. GHz gyrotrons, delivering up to kw of EC power each, create and heat the plasma using second harmonic X mode. The power of each gyrotron is guided towards the vacuum vessel by its corresponding quasioptical transmission line and two internal steerable mirrors allow us to scan the plasma toroidally and poloidally. The lines are located in stellarator symmetric positions enabling EC driven current compensation with oblique injection. The launching geometry of the two beams. T ECH Φ=9..9 T z(cm) T T - - r(cm) z(cm).9 T ρ =. ρ =. Φ=. -. T ρ =. ρ =. ECH - r(cm) FIG. : Launching directions of both ECH beams. The medium iota configuration and typical ECRH plasma profiles have been used for the ray tracing calculation. (ECH and ECH) and the several ECH off-axis positions used in the experiments are shown in figure. In general, unless otherwise stated, the launching direction of the first beam (ρ ECH =.) was kept constant. For a given launching direction given by some ρ, the EC beam points to the plasma so that, neglecting refraction effects, it crosses the EC cold resonance layer (.9 T) at this particular ρ, and perpendicularly to the magnetic fielddirection (N = ). Thefigureshowstheresult ofaraytracingcalculation performed with the TRUBA code ( rays were used). Experimental observations. NBI Plasmas Figure shows a typical NBI discharge in which several MHD modes appear during the NBI phase (t ms). In this case ECRH is only used to build the NBI target plasma. Figureshowsthespectrogramofthemagneticfieldfluctuations B(t)(mainly

3 EX/P- the fluctuations in the poloidal component of B) measured cm away from plasma by a Mirnov coil located in sector C of the device. The overlayed white curve in figure P ECH,NBI (a.u.), δ B (a.u.), <n e > ( 9 m ) P ECH P ECH P NBI <n e > (ECE) SXR δ B 7 δn (a.u.) 7 9 V beam (kv) δn (a.u.) 7 I beam (A) (c) (d) FIG. : Heating sequence and time evolution of several plasma magnitudes. Spectrogram of the magnetic field fluctuations. Amplitude of the density fluctuations at the mode frequency measured by DR, for different NBI operating regimes (c), (d). is given by α/ n e (t), where n e (t) is the line average density obtained from microwaves interferometry and α is an unknown factor that depends on the dispersion relation of the mode. Here, we have chosen alpha (α = khzcm / ) so that the curve closely follows the frequency evolution of the initial mode and therefore, disregarding profile evolution, we may identify it as an Alfvén type mode. The value taken for α will be retained throughout all the paper for comparison purposes. For modes highly localized in frequency, the standard deviation of the FFT (δb) in a short time interval ( ms) is a useful indicator of the time evolution of the fluctuations amplitude B(t) (see figure ). The continuous change of the plasma density and temperature, as well as the evolution of the profiles during the NBI phase, produces a strong variation in the frequency and the amplitude of the detected modes. A scan of the NBI parameters and its influence on the mode amplitude appears in figures (c) and (d). The data represented in the figures

4 EX/P- are the density fluctuations at the mode frequency, obtained from Doppler reflectometry (DR) []. A beam energy scan ( kv) at an approximately constant current ( ± A, blue circles in figures (c) and (d)) and a current scan ( A) at fixed beam energy (.±. kv, red circles in figures (c) and (d)) were performed. The corresponding port-through power ranges between and kw. Beam current variations have a stronger influence on the density fluctuations, probably because the fast ion drive is more dependent on the number of particles resonant with the mode than on the small variations on the resonant condition produced by the changes in the beam energy.. NBI+ECRH Plasmas The impact of ECR heating on the NBI-driven Alfvén modes has been studied using several heating configurations. First experiments were carried out with ρ ECH =. and ρ ECH =. []. As it will be shown later, having ρ ECH =. produces a strong mode (a.u.), <n e > ( 9 m ) P ECH,NBI, δ B (a.u.) P ECH P ECH P NBI δ B. <n e > (ECE) SXR 9 7 FIG. : kw NBI shot with modulated ECRH. Frequency chirping is observed a few milliseconds after the ECH switch-on. Applying further EC power with ECH at t= ms strongly reduces the mode amplitude. chirping in the medium iota (ι) configuration. Figure illustrates the case in which kw of ECH, targeting the plasma at ρ ECH =., is powered on again only ms after the starting of the NBI phase. As a consequence, the NBI driven steady mode disappears, nothing is observed during a short period of time ( 7 ms) and then, a chirping mode with f khz emerges. Note that the ECRH induced pump-out helps control the density which otherwise would gradually increase due to the NBI particle fueling. Adding further power using low frequency modulation with kw of ECH at ρ ECH =. significantly attenuates the amplitude of the chirping mode as it is clearly shown by the time evolution of the fluctuations amplitude δb, that is represented in figure ). The line density is approximately constant during the transition from ECH to ECH+ECH (t ms).

5 EX/P- Searching for the conditions for which the chirping mode appears, several ECH off-axis positions were tested, while keeping a fixed direction with the ECH beam (ρ ECH =.). In principle, power injection was carried out with N thus avoiding EC current drive. Figure shows the type of shot that was used for this purpose. In this set of experiments, ECH is shutdown after the NBI injection and only ECH is maintained during the whole shot. Depending on the ECH beam launching direction, steady or chirping modes are observed. This behavior is illustrated in figures,, (c) and (d), where the spectrogram of the fluctuations is presented for shots with different ρ ECH. 9 P P ECH PNBI δ B <ne> Te (ECE). 9 m ) Te (a.u.), <ne> ( ECH PECH,NBI, δb (a.u.) SXR. 7 FIG. : Typical NBI+ECH (.) shot and B (t) spectrogram (c) (d) FIG. : B (t) spectrogram for ρ ECH =.,.,. (c) and. (d).

6 EX/P- Mode chirping appears for ρ ECH >. while a steady mode, similar to the one observed with only NBI heating, is present when ρ ECH <.. Next, in order to check the reproducibility of the mode attenuation result, ECH power was added, always targeting at ρ ECH =. and the mode amplitude was measured both in plasma with steady (ρ ECH =.) and chirping (ρ ECH =.) mode behavior. 7 δ B ( - T) <n e > ( 9 m - ) FIG. : Steady mode amplitude vs. line density with (green points) and without (red points) ECH. Mode chirping amplitude with (top) and without (bottom) ECH. P ECH,NBI,n e,i p, P ECRH P ( ) ECRH P NBI n L () I pl time(ms) n e ( 9 m - )... (kev). P ECH,NBI,n e,i p, P ECRH P ( ) ECRH P NBI n L () I pl.. time(ms).... ρ.... ρ FIG. 7: Plasma current reversal in shots with ECH at different launching directions,. (bottom) and. (top). Plasma profiles of both shots. If the mode is well localized in the (f,t) space, as it occurs in the steady mode conditions, the dependence of its amplitude (actually δb) on the line averaged density can be obtained. This result is shown in figure where data coming from several shots has been

7 7 EX/P- used. When ECH is added, the amplitude δb is half the value encountered when only ECH is operating. The effect on the chirping mode amplitude also becomes very clear as it is shown in figure. Together with the excitation of a chirping mode, a reversal in the total plasma current I p is observed. A comparison between shots obtained at different ρ ECH is presented in figure 7). Plasma current changes its sign when the second beam is moved from ρ ECH =. to ρ ECH =.. The absolute value of I p (t) barely changes. The density and temperature profiles, that are also presented in figure 7, show almost no variation in the gradient zone, where the contribution from the bootstrap current is expected to be larger and thus, the change of the plasma current can not be explained by modifications in the plasma profiles. low ι rho=. rho=.. medium ι rho=. rho=.. δ B ( - T)... <n e > ( 9 m - ) δ B ( - T)... <n e > ( 9 m - ) δ B ( - T) high ι 7 rho=. rho=..... <n e > ( 9 m - ) ι/π low medium high ρ.... P(W/cm ) (c) (d) FIG. : Chirping mode amplitude for low, medium and high ι (c). Power deposition and ι/π profiles. Low order rational values of ι are highlighted (d). The results presented so far have been obtained in a medium ι magnetic configuration. Two alternative configurations, with low and high ι, were also investigated in shots where only ECH was operated during the whole plasma duration. Although only three configurations have been tested, it would seem that for each configuration the stronger mode chirping occurs at different launching directions (see figures and (c)). In an attempt to understand this finding, the rotational transform profiles for each configuration, as well as the power deposition profiles for each ρ are presented in figure (d). The comparison of the results for low and medium ι suggests the ex-

8 EX/P- istence of a given ι value for which frequency chirping is maximum. The same reasoning would lead us to think that the high ι case would present maximum chirping for ρ ECH =.. However, for such launching directions, mode chirping never occurs. Finally, figure 9 shows the energy spectrum of the neutral flux measured by a -channel compact neutral particle analyzer (CNPA) in three different stages of the mode chirping shot represented in figure. As it is shown in the figure, ECRH power enhances the neutral flux for energies above one third the nominal beam energy consistently with an increase of the fast ion population during the NBI+ECRH phase. Conclusions Neutral flux (a.u.) t= ms (NBI) t= ms (NBI+ECH) t= ms (NBI+ECH+ECH) Energy (kev) FIG. 9: Neutral flux spectrum from CNPA measured in shot 9 (see figures and ). EC heating modifies strongly the character and amplitude of the NBI driven AE s. Frequency chirping appears for off-axis positions beyond ρ ECH =. and whether we consider a steady or a chirping mode, the application of the other gyrotron produce a strong reduction of the mode amplitude. The fact that opposite I p is obtained in otherwise very similar shots is not yet understood. The findings regarding mode chirping amplitude in three distinct magnetic configurations suggest that the maximum amplitude of the chirping mode generated by ECRH is linked to some particular value of ι/π. The experiments were performed assuming symmetrical behavior in respect to the two ECRH beams. This has still to be tested experimentally. Acknowledgements This work was partially funded by the EUROfusion Enabling Research programme under project number ER-WP-ER- and the Spanish Ministry of Economy and Competitiveness under contract number ENE-9-P. References [] M. A. Van Zeeland et al., Plasma Phys Control Fusion 9 () [] M. A. Van Zeeland at al., Nucl. Fusion 9 (9) [] K. Nagaoka et al., Nucl. Fusion 7 () [] T. Happel et al., Rev. Sci. Instrum. 7 (9)

MHD instability driven by supra-thermal electrons in TJ-II stellarator

MHD instability driven by supra-thermal electrons in TJ-II stellarator MHD instability driven by supra-thermal electrons in TJ-II stellarator K. Nagaoka 1, S. Yamamoto 2, S. Ohshima 2, E. Ascasíbar 3, R. Jiménez-Gómez 3, C. Hidalgo 3, M.A. Pedrosa 3, M. Ochando 3, A.V. Melnikov

More information

Characterization of the Perpendicular Rotation Velocity of the Turbulence by Reflectometry in the Stellarator TJ-II

Characterization of the Perpendicular Rotation Velocity of the Turbulence by Reflectometry in the Stellarator TJ-II 1 EX/P5-31 Characterization of the Perpendicular Rotation Velocity of the Turbulence by Reflectometry in the Stellarator TJ-II T. Estrada 1), T. Happel 1), C. Hidalgo 1) 1) Laboratorio Nacional de Fusión.

More information

Spatial, temporal and spectral structure of the turbulence-flow interaction at the L-H transition

Spatial, temporal and spectral structure of the turbulence-flow interaction at the L-H transition Spatial, temporal and spectral structure of the turbulence-flow interaction at the L-H transition T Estrada 1, E. Ascasíbar 1, E. Blanco 1, A. Cappa 1, P. H. Diamond 2, T. Happel 3, C. Hidalgo 1, M. Liniers

More information

Impact of Localized ECRH on NBI and ICRH Driven Alfven Eigenmodes in the ASDEX Upgrade Tokamak

Impact of Localized ECRH on NBI and ICRH Driven Alfven Eigenmodes in the ASDEX Upgrade Tokamak Impact of Localized ECRH on NBI and ICRH Driven Alfven Eigenmodes in the ASDEX Upgrade Tokamak M. Garcia-Munoz M. A. Van Zeeland, S. Sharapov, Ph. Lauber, J. Ayllon, I. Classen, G. Conway, J. Ferreira,

More information

Active Control of Alfvén Eigenmodes in the ASDEX Upgrade tokamak

Active Control of Alfvén Eigenmodes in the ASDEX Upgrade tokamak Active Control of Alfvén Eigenmodes in the ASDEX Upgrade tokamak M. Garcia-Munoz, S. E. Sharapov, J. Ayllon, B. Bobkov, L. Chen, R. Coelho, M. Dunne, J. Ferreira, A. Figueiredo, M. Fitzgerald, J. Galdon-Quiroga,

More information

DIAGNOSTICS FOR ADVANCED TOKAMAK RESEARCH

DIAGNOSTICS FOR ADVANCED TOKAMAK RESEARCH DIAGNOSTICS FOR ADVANCED TOKAMAK RESEARCH by K.H. Burrell Presented at High Temperature Plasma Diagnostics 2 Conference Tucson, Arizona June 19 22, 2 134 /KHB/wj ROLE OF DIAGNOSTICS IN ADVANCED TOKAMAK

More information

Review of Confinement and Transport Studies in the TJ-II Flexible Heliac

Review of Confinement and Transport Studies in the TJ-II Flexible Heliac Review of Confinement and Transport Studies in the TJ-II Flexible Heliac C. Alejaldre, J. Alonso, L. Almoguera, E. Ascasíbar, A. Baciero, R. Balbín, M. Blaumoser, J. Botija, B. Brañas, E. de la Cal, A.

More information

Electron Bernstein Wave Heating in the TCV Tokamak

Electron Bernstein Wave Heating in the TCV Tokamak Electron Bernstein Wave Heating in the TCV Tokamak A. Mueck 1, Y. Camenen 1, S. Coda 1, L. Curchod 1, T.P. Goodman 1, H.P. Laqua 2, A. Pochelon 1, TCV Team 1 1 Ecole Polytechnique Fédérale de Lausanne

More information

STABILIZATION OF m=2/n=1 TEARING MODES BY ELECTRON CYCLOTRON CURRENT DRIVE IN THE DIII D TOKAMAK

STABILIZATION OF m=2/n=1 TEARING MODES BY ELECTRON CYCLOTRON CURRENT DRIVE IN THE DIII D TOKAMAK GA A24738 STABILIZATION OF m=2/n=1 TEARING MODES BY ELECTRON CYCLOTRON CURRENT DRIVE IN THE DIII D TOKAMAK by T.C. LUCE, C.C. PETTY, D.A. HUMPHREYS, R.J. LA HAYE, and R. PRATER JULY 24 DISCLAIMER This

More information

Effect of rotational transform and magnetic shear on confinement of stellarators

Effect of rotational transform and magnetic shear on confinement of stellarators Effect of rotational transform and magnetic shear on confinement of stellarators E. Ascasíbar(1), D. López-Bruna(1), F. Castejón(1), V.I. Vargas(1), V. Tribaldos(1), H. Maassberg(2), C.D. Beidler(2) R.

More information

Noninductive Formation of Spherical Tokamak at 7 Times the Plasma Cutoff Density by Electron Bernstein Wave Heating and Current Drive on LATE

Noninductive Formation of Spherical Tokamak at 7 Times the Plasma Cutoff Density by Electron Bernstein Wave Heating and Current Drive on LATE 1 EX/P6-18 Noninductive Formation of Spherical Tokamak at 7 Times the Plasma Cutoff Density by Electron Bernstein Wave Heating and Current Drive on LATE M. Uchida, T. Maekawa, H. Tanaka, F. Watanabe, Y.

More information

Microwave Reflectometry in TJ-II

Microwave Reflectometry in TJ-II Microwave Reflectometry in TJ-II E. Blanco, T. Estrada, L. Cupido*, M.E. Manso*, V. Zhuravlev** and J. Sánchez Laboratorio Nacional de Fusión, Asociación Euratom-CIEMAT, Madrid, Spain Abstract *Associação

More information

Ion Heating Experiments Using Perpendicular Neutral Beam Injection in the Large Helical Device

Ion Heating Experiments Using Perpendicular Neutral Beam Injection in the Large Helical Device Ion Heating Experiments Using Perpendicular Neutral Beam Injection in the Large Helical Device Kenichi NAGAOKA, Masayuki YOKOYAMA, Yasuhiko TAKEIRI, Katsumi IDA, Mikiro YOSHINUMA, Seikichi MATSUOKA 1),

More information

The Li-wall Stellarator Experiment in TJ-II

The Li-wall Stellarator Experiment in TJ-II The Li-wall Stellarator Experiment in TJ-II Laboratorio Nacional de Fusión. CIEMAT. Madrid. Spain Outlook Introduction Why Lithium? Li coating technique in TJ-II 2008 Results Particle recycling and confinement

More information

Reduction of Neoclassical Transport and Observation of a Fast Electron Driven Instability with Quasisymmetry in HSX

Reduction of Neoclassical Transport and Observation of a Fast Electron Driven Instability with Quasisymmetry in HSX 1 Reduction of Neoclassical Transport and Observation of a Fast Electron Driven Instability with Quasisymmetry in HSX J.M. Canik 1), D.L. Brower 2), C. Deng 2), D.T. Anderson 1), F.S.B. Anderson 1), A.F.

More information

GA A23713 RECENT ECCD EXPERIMENTAL STUDIES ON DIII D

GA A23713 RECENT ECCD EXPERIMENTAL STUDIES ON DIII D GA A271 RECENT ECCD EXPERIMENTAL STUDIES ON DIII D by C.C. PETTY, J.S. degrassie, R.W. HARVEY, Y.R. LIN-LIU, J.M. LOHR, T.C. LUCE, M.A. MAKOWSKI, Y.A. OMELCHENKO, and R. PRATER AUGUST 2001 DISCLAIMER This

More information

GA A23698 ELECTRON CYCLOTRON WAVE EXPERIMENTS ON DIII D

GA A23698 ELECTRON CYCLOTRON WAVE EXPERIMENTS ON DIII D GA A23698 ELECTRON CYCLOTRON WAVE EXPERIMENTS ON DIII D by C.C. PETTY, J.S. degrassie, R.W. HARVEY, Y.R. LIN-LIU, J.M. LOHR, T.C. LUCE, M.A. MAKOWSKI, Y.A. OMELCHENKO, and R. PRATER JUNE 21 DISCLAIMER

More information

Recent Development of LHD Experiment. O.Motojima for the LHD team National Institute for Fusion Science

Recent Development of LHD Experiment. O.Motojima for the LHD team National Institute for Fusion Science Recent Development of LHD Experiment O.Motojima for the LHD team National Institute for Fusion Science 4521 1 Primary goal of LHD project 1. Transport studies in sufficiently high n E T regime relevant

More information

Comparison of Ion Internal Transport Barrier Formation between Hydrogen and Helium Dominated Plasmas )

Comparison of Ion Internal Transport Barrier Formation between Hydrogen and Helium Dominated Plasmas ) Comparison of Ion Internal Transport Barrier Formation between Hydrogen and Helium Dominated Plasmas ) Kenichi NAGAOKA 1,2), Hiromi TAKAHASHI 1,2), Kenji TANAKA 1), Masaki OSAKABE 1,2), Sadayoshi MURAKAMI

More information

Edge and Internal Transport Barrier Formations in CHS. Identification of Zonal Flows in CHS and JIPPT-IIU

Edge and Internal Transport Barrier Formations in CHS. Identification of Zonal Flows in CHS and JIPPT-IIU Edge and Internal Transport Barrier Formations in CHS S. Okamura, T. Minami, T. Akiyama, T. Oishi, A. Fujisawa, K. Ida, H. Iguchi, M. Isobe, S. Kado, K. Nagaoka, K. Nakamura, S. Nishimura, K. Matsuoka,

More information

SUMMARY OF EXPERIMENTAL CORE TURBULENCE CHARACTERISTICS IN OH AND ECRH T-10 TOKAMAK PLASMAS

SUMMARY OF EXPERIMENTAL CORE TURBULENCE CHARACTERISTICS IN OH AND ECRH T-10 TOKAMAK PLASMAS SUMMARY OF EXPERIMENTAL CORE TURBULENCE CHARACTERISTICS IN OH AND ECRH T-1 TOKAMAK PLASMAS V. Vershkov, L.G. Eliseev, S.A. Grashin. A.V. Melnikov, D.A. Shelukhin, S.V. Soldatov, A.O. Urazbaev and T-1 team

More information

- Effect of Stochastic Field and Resonant Magnetic Perturbation on Global MHD Fluctuation -

- Effect of Stochastic Field and Resonant Magnetic Perturbation on Global MHD Fluctuation - 15TH WORKSHOP ON MHD STABILITY CONTROL: "US-Japan Workshop on 3D Magnetic Field Effects in MHD Control" U. Wisconsin, Madison, Nov 15-17, 17, 2010 LHD experiments relevant to Tokamak MHD control - Effect

More information

Beam Driven Alfvén Eigenmodes and Fast Ion Transport in the DIII-D and ASDEX Upgrade (AUG) Tokamaks

Beam Driven Alfvén Eigenmodes and Fast Ion Transport in the DIII-D and ASDEX Upgrade (AUG) Tokamaks Beam Driven Alfvén Eigenmodes and Fast Ion Transport in the DIII-D and ASDEX Upgrade (AUG) Tokamaks by M.A. Van Zeeland 1 M. García-Muñoz 2, W.W. Heidbrink 3, I. Classen 4, R.K. Fisher 1, B. Geiger 2,

More information

Pellet injection experiments in LHD

Pellet injection experiments in LHD Published by Fusion Energy Division, Oak Ridge National Laboratory Building 921-2 P.O. Box 29 Oak Ridge, TN 37831-871, USA Editor: James A. Rome Issue 68 March 2 E-Mail: jar@y12.doe.gov Phone (865) 574-136

More information

Transport Improvement Near Low Order Rational q Surfaces in DIII D

Transport Improvement Near Low Order Rational q Surfaces in DIII D Transport Improvement Near Low Order Rational q Surfaces in DIII D M.E. Austin 1 With K.H. Burrell 2, R.E. Waltz 2, K.W. Gentle 1, E.J. Doyle 8, P. Gohil 2, C.M. Greenfield 2, R.J. Groebner 2, W.W. Heidbrink

More information

On Electron-Cyclotron Waves in Relativistic Non-Thermal Tokamak Plasmas

On Electron-Cyclotron Waves in Relativistic Non-Thermal Tokamak Plasmas 1 On Electron-Cyclotron Waves in Relativistic Non-Thermal Tokamak Plasmas Lj. Nikolić and M.M. Škorić Vinča Institute of Nuclear Sciences, P.O.Box 522, Belgrade 11001, Serbia and Montenegro ljnikoli@tesla.rcub.bg.ac.yu

More information

Active MHD Control Needs in Helical Configurations

Active MHD Control Needs in Helical Configurations 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, A. Reiman 1, and the W7-AS Team and NBI-Group. 1 Princeton Plasma

More information

1 EX/C4-3. Increased Understanding of Neoclassical Internal Transport Barrier on CHS

1 EX/C4-3. Increased Understanding of Neoclassical Internal Transport Barrier on CHS EX/C-3 Increased Understanding of Neoclassical Internal Transport Barrier on CHS T.Minami, A.Fujisawa, H.Iguchi, Y.Liang, K.Ida, S.Nishimura, M.Yokoyama, S.Murakami, Y.Yoshimura, M.Isobe, C.Suzuki, I.Nomura,

More information

First plasma operation of Wendelstein 7-X

First plasma operation of Wendelstein 7-X First plasma operation of Wendelstein 7-X R. C. Wolf on behalf of the W7-X Team *) robert.wolf@ipp.mpg.de *) see author list Bosch et al. Nucl. Fusion 53 (2013) 126001 The optimized stellarator Wendelstein

More information

Excitation of Alfvén eigenmodes with sub-alfvénic neutral beam ions in JET and DIII-D plasmas

Excitation of Alfvén eigenmodes with sub-alfvénic neutral beam ions in JET and DIII-D plasmas Excitation of Alfvén eigenmodes with sub-alfvénic neutral beam ions in JET and DIII-D plasmas D. Borba 1,9, R. Nazikian 2, B. Alper 3, H.L. Berk 4, A. Boboc 3, R.V. Budny 2, K.H. Burrell 5, M. De Baar

More information

Ion orbits and ion confinement studies on ECRH plasmas in TJ-II stellarator

Ion orbits and ion confinement studies on ECRH plasmas in TJ-II stellarator Ion orbits and ion confinement studies on ECRH plasmas in TJ-II stellarator F. Castejón 1,4, J. M. Reynolds 3,4, J. M. Fontdecaba 1, D. López-Bruna 1, R. Balbín 1, J. Guasp 1, D. Fernández-Fraile 2, L.

More information

Localized Electron Cyclotron Current Drive in DIII D: Experiment and Theory

Localized Electron Cyclotron Current Drive in DIII D: Experiment and Theory Localized Electron Cyclotron Current Drive in : Experiment and Theory by Y.R. Lin-Liu for C.C. Petty, T.C. Luce, R.W. Harvey,* L.L. Lao, P.A. Politzer, J. Lohr, M.A. Makowski, H.E. St John, A.D. Turnbull,

More information

Magnetic Field Configuration Dependence of Plasma Production and Parallel Transport in a Linear Plasma Device NUMBER )

Magnetic Field Configuration Dependence of Plasma Production and Parallel Transport in a Linear Plasma Device NUMBER ) Magnetic Field Configuration Dependence of Plasma Production and Parallel Transport in a Linear Plasma Device NUMBER ) Daichi HAMADA, Atsushi OKAMOTO, Takaaki FUJITA, Hideki ARIMOTO, Katsuya SATOU and

More information

Relating the L-H Power Threshold Scaling to Edge Turbulence Dynamics

Relating the L-H Power Threshold Scaling to Edge Turbulence Dynamics Relating the L-H Power Threshold Scaling to Edge Turbulence Dynamics Z. Yan 1, G.R. McKee 1, J.A. Boedo 2, D.L. Rudakov 2, P.H. Diamond 2, G. Tynan 2, R.J. Fonck 1, R.J. Groebner 3, T.H. Osborne 3, and

More information

3D effects on transport and plasma control in the TJ-II stellarator

3D effects on transport and plasma control in the TJ-II stellarator 1 3D effects on transport and plasma control in the TJ-II stellarator F. Castejón 1 and the TJ-II team 1 and collaborators 2 1 Laboratorio Nacional de Fusión, CIEMAT, 28040, Madrid, Spain 2 Institute of

More information

Observation of Reduced Core Electron Temperature Fluctuations and Intermediate Wavenumber Density Fluctuations in H- and QH-mode Plasmas

Observation of Reduced Core Electron Temperature Fluctuations and Intermediate Wavenumber Density Fluctuations in H- and QH-mode Plasmas Observation of Reduced Core Electron Temperature Fluctuations and Intermediate Wavenumber Density Fluctuations in H- and QH-mode Plasmas EX/P5-35 L. Schmitz 1), A.E. White 1), G. Wang 1), J.C. DeBoo 2),

More information

On the physics of shear flows in 3D geometry

On the physics of shear flows in 3D geometry On the physics of shear flows in 3D geometry C. Hidalgo and M.A. Pedrosa Laboratorio Nacional de Fusión, EURATOM-CIEMAT, Madrid, Spain Recent experiments have shown the importance of multi-scale (long-range)

More information

Additional Heating Experiments of FRC Plasma

Additional Heating Experiments of FRC Plasma Additional Heating Experiments of FRC Plasma S. Okada, T. Asai, F. Kodera, K. Kitano, T. Suzuki, K. Yamanaka, T. Kanki, M. Inomoto, S. Yoshimura, M. Okubo, S. Sugimoto, S. Ohi, S. Goto, Plasma Physics

More information

Heating and Current Drive by Electron Cyclotron Waves in JT-60U

Heating and Current Drive by Electron Cyclotron Waves in JT-60U EX/W- Heating and Current Drive by Electron Cyclotron Waves in JT-6U T. Suzuki ), S. Ide ), C. C. Petty ), Y. Ikeda ), K. Kajiwara ), A. Isayama ), K. Hamamatsu ), O. Naito ), M. Seki ), S. Moriyama )

More information

GA A24016 PHYSICS OF OFF-AXIS ELECTRON CYCLOTRON CURRENT DRIVE

GA A24016 PHYSICS OF OFF-AXIS ELECTRON CYCLOTRON CURRENT DRIVE GA A6 PHYSICS OF OFF-AXIS ELECTRON CYCLOTRON CURRENT DRIVE by R. PRATER, C.C. PETTY, R. HARVEY, Y.R. LIN-LIU, J.M. LOHR, and T.C. LUCE JULY DISCLAIMER This report was prepared as an account of work sponsored

More information

Study of chirping Toroidicity-induced Alfvén Eigenmodes in the National Spherical Torus Experiment

Study of chirping Toroidicity-induced Alfvén Eigenmodes in the National Spherical Torus Experiment Study of chirping Toroidicity-induced Alfvén Eigenmodes in the National Spherical Torus Experiment M. Podestà 1, R. E. Bell 1, A. Bortolon 2, N. A. Crocker 3, D. S. Darrow 1, E. D. Fredrickson 1, G.-Y.

More information

Behavior of Compact Toroid Injected into the External Magnetic Field

Behavior of Compact Toroid Injected into the External Magnetic Field Behavior of Compact Toroid Injected into the External Magnetic Field M. Nagata 1), N. Fukumoto 1), H. Ogawa 2), T. Ogawa 2), K. Uehara 2), H. Niimi 3), T. Shibata 2), Y. Suzuki 4), Y. Miura 2), N. Kayukawa

More information

M.Osakabe, T.Itoh1, K. Ogawa3,4, M. Isobe1,2, K. Toi1,3, T.Ido1,3, A. Shimizu1, S. Kubo1,3, K.Nagaoka1, Y.Takeiri1,2 and LHD experiment group

M.Osakabe, T.Itoh1, K. Ogawa3,4, M. Isobe1,2, K. Toi1,3, T.Ido1,3, A. Shimizu1, S. Kubo1,3, K.Nagaoka1, Y.Takeiri1,2 and LHD experiment group 5th IAEA-TM on EP September 5-10, 2011 Austin, Texas M.Osakabe, T.Itoh1, K. Ogawa3,4, M. Isobe1,2, K. Toi1,3, T.Ido1,3, A. Shimizu1, S. Kubo1,3, K.Nagaoka1, Y.Takeiri1,2 and LHD experiment group 1National

More information

Upper Hybrid Resonance Backscattering Enhanced Doppler Effect and Plasma Rotation Diagnostics at FT-2 Tokamak

Upper Hybrid Resonance Backscattering Enhanced Doppler Effect and Plasma Rotation Diagnostics at FT-2 Tokamak Upper Hybrid Resonance Backscattering Enhanced Doppler Effect and Plasma Rotation Diagnostics at FT- Tokamak A.B. Altukhov ), V.V. Bulanin ), V.V. Dyachenko ), L.A. Esipov ), M.V. Gorokhov ), A.D. Gurchenko

More information

1) H-mode in Helical Devices. 2) Construction status and scientific objectives of the Wendelstein 7-X stellarator

1) H-mode in Helical Devices. 2) Construction status and scientific objectives of the Wendelstein 7-X stellarator Max-Planck-Institut für Plasmaphysik 1) H-mode in Helical Devices M. Hirsch 1, T. Akiyama 2, T.Estrada 3, T. Mizuuchi 4, K. Toi 2, C. Hidalgo 3 1 Max-Planck-Institut für Plasmaphysik, EURATOM-Ass., D-17489

More information

Plasma Start-Up Results with EC Assisted Breakdown on FTU

Plasma Start-Up Results with EC Assisted Breakdown on FTU 1 EXW/P2-03 Plasma Start-Up Results with EC Assisted Breakdown on FTU G. Granucci 1), G. Ramponi 1), G. Calabrò 2), F. Crisanti 2), G. Ramogida 2), W. Bin 1), A. Botrugno 2), P.Buratti 2), O. D Arcangelo1,

More information

Bifurcation-Like Behavior of Electrostatic Potential in LHD )

Bifurcation-Like Behavior of Electrostatic Potential in LHD ) Bifurcation-Like Behavior of Electrostatic Potential in LHD ) Akihiro SHIMIZU, Takeshi IDO, Masaki NISHIURA, Ryohei MAKINO 1), Masayuki YOKOYAMA, Hiromi TAKAHASHI, Hiroe IGAMI, Yasuo YOSHIMURA, Shin KUBO,

More information

Nonlinear processes associated with Alfvén waves in a laboratory plasma

Nonlinear processes associated with Alfvén waves in a laboratory plasma Nonlinear processes associated with Alfvén waves in a laboratory plasma Troy Carter Dept. Physics and Astronomy and Center for Multiscale Plasma Dynamics, UCLA acknowledgements: Brian Brugman, David Auerbach,

More information

Physics and Operations Plan for LDX

Physics and Operations Plan for LDX Physics and Operations Plan for LDX Columbia University A. Hansen D.T. Garnier, M.E. Mauel, T. Sunn Pedersen, E. Ortiz Columbia University J. Kesner, C.M. Jones, I. Karim, P. Michael, J. Minervini, A.

More information

Observations of Counter-Current Toroidal Rotation in Alcator C-Mod LHCD Plasmas

Observations of Counter-Current Toroidal Rotation in Alcator C-Mod LHCD Plasmas 1 EX/P5-4 Observations of Counter-Current Toroidal Rotation in Alcator C-Mod LHCD Plasmas J.E. Rice 1), A.C. Ince-Cushman 1), P.T. Bonoli 1), M.J. Greenwald 1), J.W. Hughes 1), R.R. Parker 1), M.L. Reinke

More information

Der Stellarator Ein alternatives Einschlusskonzept für ein Fusionskraftwerk

Der Stellarator Ein alternatives Einschlusskonzept für ein Fusionskraftwerk Max-Planck-Institut für Plasmaphysik Der Stellarator Ein alternatives Einschlusskonzept für ein Fusionskraftwerk Robert Wolf robert.wolf@ipp.mpg.de www.ipp.mpg.de Contents Magnetic confinement The stellarator

More information

Heating and current drive: Radio Frequency

Heating and current drive: Radio Frequency Heating and current drive: Radio Frequency Dr Ben Dudson Department of Physics, University of York Heslington, York YO10 5DD, UK 13 th February 2012 Dr Ben Dudson Magnetic Confinement Fusion (1 of 26)

More information

Analysis and modelling of MHD instabilities in DIII-D plasmas for the ITER mission

Analysis and modelling of MHD instabilities in DIII-D plasmas for the ITER mission Analysis and modelling of MHD instabilities in DIII-D plasmas for the ITER mission by F. Turco 1 with J.M. Hanson 1, A.D. Turnbull 2, G.A. Navratil 1, C. Paz-Soldan 2, F. Carpanese 3, C.C. Petty 2, T.C.

More information

Effects of stellarator transform on sawtooth oscillations in CTH. Jeffrey Herfindal

Effects of stellarator transform on sawtooth oscillations in CTH. Jeffrey Herfindal Effects of stellarator transform on sawtooth oscillations in CTH Jeffrey Herfindal D.A. Ennis, J.D. Hanson, G.J. Hartwell, E.C. Howell, C.A. Johnson, S.F. Knowlton, X. Ma, D.A. Maurer, M.D. Pandya, N.A.

More information

Progress of Confinement Physics Study in Compact Helical System

Progress of Confinement Physics Study in Compact Helical System 1st IAEA Fusion Energy Conference Chengdu, China, 16-1 October, 6 IAEA-CN-149/ EX/5-5Rb Progress of Confinement Physics Study in Compact Helical System S. Okamura et al. NIFS-839 Oct. 6 1 EX/5-5Rb Progress

More information

OVERVIEW of FTU RESULTS

OVERVIEW of FTU RESULTS OVERVIEW of FTU RESULTS Angelo A. Tuccillo on behalf of FTU and ECRH teams and A. Alekseyev, V. Lazarev, S. Mirnov (TRINITI, Troitsk, RF) A. Biancalani, F. Pegoraro (University of Pisa) L. Chen (University

More information

Overview of Tokamak Rotation and Momentum Transport Phenomenology and Motivations

Overview of Tokamak Rotation and Momentum Transport Phenomenology and Motivations Overview of Tokamak Rotation and Momentum Transport Phenomenology and Motivations Lecture by: P.H. Diamond Notes by: C.J. Lee March 19, 2014 Abstract Toroidal rotation is a key part of the design of ITER

More information

Observation of Neo-Classical Ion Pinch in the Electric Tokamak*

Observation of Neo-Classical Ion Pinch in the Electric Tokamak* 1 EX/P6-29 Observation of Neo-Classical Ion Pinch in the Electric Tokamak* R. J. Taylor, T. A. Carter, J.-L. Gauvreau, P.-A. Gourdain, A. Grossman, D. J. LaFonteese, D. C. Pace, L. W. Schmitz, A. E. White,

More information

Dynamics of ion internal transport barrier in LHD heliotron and JT-60U tokamak plasmas

Dynamics of ion internal transport barrier in LHD heliotron and JT-60U tokamak plasmas Dynamics of ion internal transport barrier in LHD heliotron and JT-60U tokamak plasmas K. Ida 1), Y. Sakamoto 2), M. Yoshinuma 1), H. Takenaga 2), K. Nagaoka 1), N. Oyama 2), M. Osakabe 1), M. Yokoyama

More information

Particle transport results from collisionality scans and perturbative experiments on DIII-D

Particle transport results from collisionality scans and perturbative experiments on DIII-D 1 EX/P3-26 Particle transport results from collisionality scans and perturbative experiments on DIII-D E.J. Doyle 1), L. Zeng 1), G.M. Staebler 2), T.E. Evans 2), T.C. Luce 2), G.R. McKee 3), S. Mordijck

More information

Experiments with a Supported Dipole

Experiments with a Supported Dipole Experiments with a Supported Dipole Reporting Measurements of the Interchange Instability Excited by Electron Pressure and Centrifugal Force Introduction Ben Levitt and Dmitry Maslovsky Collisionless Terrella

More information

Control of Neo-classical tearing mode (NTM) in advanced scenarios

Control of Neo-classical tearing mode (NTM) in advanced scenarios FIRST CHENGDU THEORY FESTIVAL Control of Neo-classical tearing mode (NTM) in advanced scenarios Zheng-Xiong Wang Dalian University of Technology (DLUT) Dalian, China Chengdu, China, 28 Aug, 2018 Outline

More information

Direct drive by cyclotron heating can explain spontaneous rotation in tokamaks

Direct drive by cyclotron heating can explain spontaneous rotation in tokamaks Direct drive by cyclotron heating can explain spontaneous rotation in tokamaks J. W. Van Dam and L.-J. Zheng Institute for Fusion Studies University of Texas at Austin 12th US-EU Transport Task Force Annual

More information

Performance, Heating, and Current Drive Scenarios of ASDEX Upgrade Advanced Tokamak Discharges

Performance, Heating, and Current Drive Scenarios of ASDEX Upgrade Advanced Tokamak Discharges Performance, Heating, and Current Drive Scenarios of ASDEX Upgrade Advanced Tokamak Discharges R. C. Wolf, J. Hobirk, G. Conway, O. Gruber, A. Gude, S. Günter, K. Kirov, B. Kurzan, M. Maraschek, P. J.

More information

Time-dependent Modeling of Sustained Advanced Tokamak Scenarios

Time-dependent Modeling of Sustained Advanced Tokamak Scenarios Time-dependent Modeling of Sustained Advanced Tokamak Scenarios T. A. Casper, L. L. LoDestro and L. D. Pearlstein LLNL M. Murakami ORNL L.L. Lao and H.E. StJohn GA We are modeling time-dependent behavior

More information

Characteristics of Energetic-Ion-Driven Geodesic Acoustic Modes in the Large Helical Device(LHD)

Characteristics of Energetic-Ion-Driven Geodesic Acoustic Modes in the Large Helical Device(LHD) O-4 12 th IAEA TM on Energetic Particles in Magnetic Confinement Systems, 7-10 Sep, Austin, USA Characteristics of Energetic-Ion-Driven Geodesic Acoustic Modes in the Large Helical Device(LHD) K. Toi,

More information

Studies on Neutral Beam Ion Confinement and MHD Induced Fast-Ion. Loss on HL-2A Tokamak

Studies on Neutral Beam Ion Confinement and MHD Induced Fast-Ion. Loss on HL-2A Tokamak Studies on Neutral Beam Ion Confinement and MHD Induced Fast-Ion Loss on HL-A Tokamak LIU Yi, ISOBE Mitsutaka, PENG Xiao-Dong, Wang Hao, JI Xiao-Quan, CHEN Wei, ZHANG Yi-Po, Dong Yun-Bo, MORITA Shigeru

More information

Fluctuation Suppression during the ECH Induced Potential Formation in the Tandem Mirror GAMMA 10

Fluctuation Suppression during the ECH Induced Potential Formation in the Tandem Mirror GAMMA 10 EXC/P8-2 Fluctuation Suppression during the ECH Induced Potential Formation in the Tandem Mirror GAMMA M. Yoshikawa ), Y. Miyata ), M. Mizuguchi ), Y. Oono ), F. Yaguchi ), M. Ichimura ), T. Imai ), T.

More information

Density Collapse in Improved Confinement Mode on Tohoku University Heliac

Density Collapse in Improved Confinement Mode on Tohoku University Heliac 1 EX/P5-12 Density Collapse in Improved Confinement Mode on Tohoku University Heliac S. Kitajima 1), Y. Tanaka 2), H. Utoh 1), H. Umetsu 1), J. Sato 1), K. Ishii 1), T. Kobuchi 1), A. Okamoto 1), M. Sasao

More information

Characterization of neo-classical tearing modes in high-performance I- mode plasmas with ICRF mode conversion flow drive on Alcator C-Mod

Characterization of neo-classical tearing modes in high-performance I- mode plasmas with ICRF mode conversion flow drive on Alcator C-Mod 1 EX/P4-22 Characterization of neo-classical tearing modes in high-performance I- mode plasmas with ICRF mode conversion flow drive on Alcator C-Mod Y. Lin, R.S. Granetz, A.E. Hubbard, M.L. Reinke, J.E.

More information

Phase ramping and modulation of reflectometer signals

Phase ramping and modulation of reflectometer signals 4th Intl. Reflectometry Workshop - IRW4, Cadarache, March 22nd - 24th 1999 1 Phase ramping and modulation of reflectometer signals G.D.Conway, D.V.Bartlett, P.E.Stott JET Joint Undertaking, Abingdon, Oxon,

More information

Current Drive Experiments in the HIT-II Spherical Tokamak

Current Drive Experiments in the HIT-II Spherical Tokamak Current Drive Experiments in the HIT-II Spherical Tokamak T. R. Jarboe, P. Gu, V. A. Izzo, P. E. Jewell, K. J. McCollam, B. A. Nelson, R. Raman, A. J. Redd, P. E. Sieck, and R. J. Smith, Aerospace & Energetics

More information

and expectations for the future

and expectations for the future 39 th Annual Meeting of the FPA 2018 First operation of the Wendelstein 7-X stellarator and expectations for the future Hans-Stephan Bosch Max-Planck-Institut für Plasmaphysik Greifswald, Germany on behalf

More information

Production of Over-dense Plasmas by Launching. 2.45GHz Electron Cyclotron Waves in a Helical Device

Production of Over-dense Plasmas by Launching. 2.45GHz Electron Cyclotron Waves in a Helical Device Production of Over-dense Plasmas by Launching 2.45GHz Electron Cyclotron Waves in a Helical Device R. Ikeda a, M. Takeuchi a, T. Ito a, K. Toi b, C. Suzuki b, G. Matsunaga c, S. Okamura b, and CHS Group

More information

Advanced Tokamak Research in JT-60U and JT-60SA

Advanced Tokamak Research in JT-60U and JT-60SA I-07 Advanced Tokamak Research in and JT-60SA A. Isayama for the JT-60 team 18th International Toki Conference (ITC18) December 9-12, 2008 Ceratopia Toki, Toki Gifu JAPAN Contents Advanced tokamak development

More information

Impact of Energetic-Ion-Driven Global Modes on Toroidal Plasma Confinements

Impact of Energetic-Ion-Driven Global Modes on Toroidal Plasma Confinements Impact of Energetic-Ion-Driven Global Modes on Toroidal Plasma Confinements Kazuo TOI CHS & LHD Experimental Group National Institute for Fusion Science Toki 59-5292, Japan Special contributions from:

More information

Study of High-energy Ion Tail Formation with Second Harmonic ICRF Heating and NBI in LHD

Study of High-energy Ion Tail Formation with Second Harmonic ICRF Heating and NBI in LHD 21st IAEA Fusion Energy Conference Chengdu, China, 16-21 October, 2006 IAEA-CN-149/ Study of High-energy Ion Tail Formation with Second Harmonic ICRF Heating and NBI in LHD K. Saito et al. NIFS-851 Oct.

More information

Energetic-Ion Driven Alfvén Eigenmodes in Large Helical Device Plasmas with Three-Dimensional Structure and Their Impact on Energetic Ion Transport

Energetic-Ion Driven Alfvén Eigenmodes in Large Helical Device Plasmas with Three-Dimensional Structure and Their Impact on Energetic Ion Transport Energetic-Ion Driven Alfvén Eigenmodes in Large Helical Device Plasmas with Three-Dimensional Structure and Their Impact on Energetic Ion Transport K. Toi, S. Yamamoto 1), N. Nakajima, S. Ohdachi, S. Sakakibara,

More information

Plasmoid Motion in Helical Plasmas

Plasmoid Motion in Helical Plasmas Plasmoid Motion in Helical Plasmas Ryuichi ISHIZAKI and Noriyoshi NAKAJIMA National Institute for Fusion Science, Toki 509-5292, Japan (Received 12 December 2009 / Accepted 18 May 2010) In order to explain

More information

Effect of Magnetic Shear on Propagation and Absorption of EC Waves

Effect of Magnetic Shear on Propagation and Absorption of EC Waves Japan-Korea Workshop on Heating and Current Drive KSTAR Conference, Daejeon Convention Center, Feb. 5-7, 015 Effect of Magnetic Shear on Propagation and Absorption of EC Waves Presented by K. Nagasaki

More information

High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University Heliac

High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University Heliac J. Plasma Fusion Res. SERIES, Vol. 8 (2009) High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University Heliac Hiroyasu UTOH, Kiyohiko NISHIMURA 1), Hajime UMETSU, Keiichi ISHII,

More information

Destruction of a Magnetic Mirror-Trapped Hot Electron Ring by a shear Alfven Wave

Destruction of a Magnetic Mirror-Trapped Hot Electron Ring by a shear Alfven Wave Destruction of a Magnetic Mirror-Trapped Hot Electron Ring by a shear Alfven Wave Y. Wang 1, W. Gekelman 1, P. Pribyl 1, D. Papadopoulos 2 1 University of California, Los Angeles 2 University of Maryland,

More information

Energetic-Ion-Driven MHD Instab. & Transport: Simulation Methods, V&V and Predictions

Energetic-Ion-Driven MHD Instab. & Transport: Simulation Methods, V&V and Predictions Energetic-Ion-Driven MHD Instab. & Transport: Simulation Methods, V&V and Predictions 7th APTWG Intl. Conference 5-8 June 2017 Nagoya Univ., Nagoya, Japan Andreas Bierwage, Yasushi Todo 14.1MeV 10 kev

More information

Corresponding Authors s address:

Corresponding Authors s  address: Role of SMBI deposition in ELM mitigation and the underlying turbulence characteristics Z. B. Shi 1), Z. C. Yang 1), W. L. Zhong 1), B. Y. Zhang 1), C. Y. Chen 1), M. Jiang 1), P. W. Shi 1), W. Chen 1),

More information

Reduction of Neoclassical Transport and Observation of a Fast Electron Driven Instability with Quasisymmetry in HSX

Reduction of Neoclassical Transport and Observation of a Fast Electron Driven Instability with Quasisymmetry in HSX Reduction of Neoclassical Transport and Observation of a Fast Electron Driven Instability with Quasisymmetry in HSX J.M. Canik 1, D.L. Brower 2, C. Deng 2, D.T.Anderson 1, F.S.B. Anderson 1, A.F. Almagri

More information

Plan of Off-axis Neutral Beam Injector in KSTAR

Plan of Off-axis Neutral Beam Injector in KSTAR KSTAR conference, Feb 25-27, 2015, Daejeon (DCC), Korea Plan of Off-axis Neutral Beam Injector in KSTAR Feb. 26, 2015 DCC, Daejeon, Korea Young-soon Bae a L. Terzolo a, K.S. Lee a, H.K. Kim a, H.L. Yang

More information

Control of Sawtooth Oscillation Dynamics using Externally Applied Stellarator Transform. Jeffrey Herfindal

Control of Sawtooth Oscillation Dynamics using Externally Applied Stellarator Transform. Jeffrey Herfindal Control of Sawtooth Oscillation Dynamics using Externally Applied Stellarator Transform Jeffrey Herfindal D.A. Ennis, J.D. Hanson, G.J. Hartwell, S.F. Knowlton, X. Ma, D.A. Maurer, M.D. Pandya, N.A. Roberds,

More information

Toroidal confinement of non-neutral plasma. Martin Droba

Toroidal confinement of non-neutral plasma. Martin Droba Toroidal confinement of non-neutral plasma Martin Droba Contents Experiments with toroidal non-neutral plasma Magnetic surfaces CNT and IAP-high current ring Conclusion 2. Experiments with toroidal non-neutral

More information

Observation of modes at frequencies above the Alfvén frequency in JET

Observation of modes at frequencies above the Alfvén frequency in JET Observation of modes at frequencies above the Alfvén frequency in JET F. Nabais 1, D. Borba 1, R. Coelho 1, L. Fazendeiro 1, J. Ferreira 1, A. Figueiredo 1, L. Fitzgerald 2, P. Rodrigues 1, S. Sharapov

More information

Simulation Study of Interaction between Energetic Ions and Alfvén Eigenmodes in LHD

Simulation Study of Interaction between Energetic Ions and Alfvén Eigenmodes in LHD 1 Simulation Study of Interaction between Energetic Ions and Alfvén Eigenmodes in LHD Y. Todo 1), N. Nakajima 1), M. Osakabe 1), S. Yamamoto 2), D. A. Spong 3) 1) National Institute for Fusion Science,

More information

GA A23977 DETAILED MEASUREMENTS OF ECCD EFFICIENCY ON DIII D FOR COMPARISON WITH THEORY

GA A23977 DETAILED MEASUREMENTS OF ECCD EFFICIENCY ON DIII D FOR COMPARISON WITH THEORY GA A23977 DETAILED MEASUREMENTS OF ECCD EFFICIENCY ON DIII D by C.C. PETTY, R. PRATER, J. LOHR, T.C. LUCE, R.A. ELLIS, III, R.W. HARVEY, J.E. KINSEY, L.L. LAO, and M.A. MAKOWSKI MAY 2002 DISCLAIMER This

More information

GA A25853 FAST ION REDISTRIBUTION AND IMPLICATIONS FOR THE HYBRID REGIME

GA A25853 FAST ION REDISTRIBUTION AND IMPLICATIONS FOR THE HYBRID REGIME GA A25853 FAST ION REDISTRIBUTION AND IMPLICATIONS FOR THE HYBRID REGIME by R. NAZIKIAN, M.E. AUSTIN, R.V. BUDNY, M.S. CHU, W.W. HEIDBRINK, M.A. MAKOWSKI, C.C. PETTY, P.A. POLITZER, W.M. SOLOMON, M.A.

More information

Effect of ECRH Regime on Characteristics of Short-Wave Turbulence in Plasma of the L-2M Stellarator

Effect of ECRH Regime on Characteristics of Short-Wave Turbulence in Plasma of the L-2M Stellarator 1 Effect of ECRH Regime on Characteristics of Short-Wave Turbulence in Plasma of the L-2M Stellarator N.N. Skvortsova, D.K. Akulina, G.M. Batanov, G.S. Voronov, L.V. Kolik, L.M. Kovrizhnykh, A.A. Letunov,

More information

Plasma Stability in Tokamaks and Stellarators

Plasma Stability in Tokamaks and Stellarators Plasma Stability in Tokamaks and Stellarators Gerald A. Navratil GCEP Fusion Energy Workshop Princeton, NJ 1- May 006 ACKNOWLEDGEMENTS Borrowed VGs from many colleagues: J. Bialek, A. Garofalo,R. Goldston,

More information

Research of Basic Plasma Physics Toward Nuclear Fusion in LHD

Research of Basic Plasma Physics Toward Nuclear Fusion in LHD Research of Basic Plasma Physics Toward Nuclear Fusion in LHD Akio KOMORI and LHD experiment group National Institute for Fusion Science, Toki, Gifu 509-5292, Japan (Received 4 January 2010 / Accepted

More information

Configuration Control Experiments in Heliotron J

Configuration Control Experiments in Heliotron J J. Plasma Fusion Res. SERIES, Vol. 8 (29) Configuration Control Experiments in Heliotron J Tohru MIZUUCHI, Shinji KOBAYASHI, Hiroyuki OKADA, Kazunobu NAGASAKI, Satoshi YAMAMOTO, Gen MOTOJIMA b, Shinya

More information

Overview of TJ-II experiments

Overview of TJ-II experiments 1 Overview of TJ-II experiments J. Sánchez and the TJ-II Team Asociación EURATOM/CIEMAT, Av. Complutense 22, 284, Madrid, Spain. BIFI, Zaragoza, Spain. NSC KIPT, Kharkov, Ukraine. RNC Kurchatov Institute,

More information

C-Mod Core Transport Program. Presented by Martin Greenwald C-Mod PAC Feb. 6-8, 2008 MIT Plasma Science & Fusion Center

C-Mod Core Transport Program. Presented by Martin Greenwald C-Mod PAC Feb. 6-8, 2008 MIT Plasma Science & Fusion Center C-Mod Core Transport Program Presented by Martin Greenwald C-Mod PAC Feb. 6-8, 2008 MIT Plasma Science & Fusion Center Practical Motivations for Transport Research Overall plasma behavior must be robustly

More information

Role of Low-Order Rational Surfaces in Transport Barrier Formation on the Large Helical Device

Role of Low-Order Rational Surfaces in Transport Barrier Formation on the Large Helical Device Role of Low-Order Rational Surfaces in Transport Barrier Formation on the Large Helical Device K. Toi, F. Watanabe a, K. Tanaka, T. Tokuzawa, K. Ogawa b, M. Isobe, M. Osakabe, Y. Suzuki, T. Akiyama, K.

More information

Resistive Wall Mode Control in DIII-D

Resistive Wall Mode Control in DIII-D Resistive Wall Mode Control in DIII-D by Andrea M. Garofalo 1 for G.L. Jackson 2, R.J. La Haye 2, M. Okabayashi 3, H. Reimerdes 1, E.J. Strait 2, R.J. Groebner 2, Y. In 4, M.J. Lanctot 1, G.A. Navratil

More information