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

Save this PDF as:

Size: px
Start display at page:

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

Transcription

1 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. Rice, S.M. Wolfe, S.J. Wukitch, and the Alcator C-Mod Team Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA contact of main author: Abstract Neo-classical tearing modes (NTMs) have been observed on Alcator C-Mod. The NTMs occur in high performance I-mode plasmas that are heated by a combination of ICRF D(H) minority heating at 80 MHz and D( 3 He) mode conversion (MC) heating at 50 MHz. I-mode plasmas have confinement as good as H-mode but lower collisionality. Due to the stabilizing effect by the energetic minority hydrogen ions, long sawtooth ( 40 ms) and large sawtooth crashes ( T e0 3 kev) are produced in these hot (T e 9 kev) plasmas. A typical case is that soon after the plasma enters I-mode, a (m = 4, n = 3) mode (f = khz) appears following a large sawtooth crash, and then a (3, 2) mode (20-40 khz) appears later at slightly higher β N. The (3, 2) mode can also occur without a preceding (4, 3) mode. In some plasmas, a (2, 1) mode may appear simultaneously with the (3, 2) mode, and lead to disruption. The onset criterion of the (3, 2) NTMs approximately follows that obtained from DIII-D and ASDEX Upgrade. The onset parameters are β P ~ , β N ~ , β N /ρ i * ~ , ν NTM (q=3/2) ~ The saturated magnetic island width of the (4, 3) mode is typically W sat ~ cm, and the mode usually has an insignificant effect on confinement. For the (3, 2) mode, W sat ~ cm, which is 3-4 times the ion banana width, and the mode can cause small confinement degradation ( β/β ~ a few percent). The NTMs have a strong effect on plasma rotation. MC flow drive generates large toroidal rotation above 100 km/sec in L-mode, and when the plasma enters I-mode, plasma rotation is expected to increase significantly due to the additional intrinsic rotation torque from the edge T e pedestal. However, the rotation almost always stops rising after the onset of the NTM(s). The appearance of the (3, 2) mode usually rapidly reduces the rotation speed, and the (2, 1) mode, if occurs, would completely halt the rotation. 1. Introduction Since its first observation on TFTR [1], neo-classical tearing modes (NTMs) have been observed in many major tokamaks [2,3,4,5,6]. Being non-ideal MHD modes, NTMs impose a soft limit on plasma performance, and they need to be controlled on ITER in order to achieve high performance. The basic mechanism for the onset of NTMs can be summarized as following: A magnetic island eliminates the radial pressure gradient inside the island, and this flattened pressure profile removes the local bootstrap current. And the removal of bootstrap current then further increases the magnetic island. The island would grow until the drive from the loss of bootstrap current is balanced by the equilibrium current gradient. The result saturated island often has a significant radial width and thus it affects plasma global energy and particle confinement. At small island width, NTMs are stable, thus a triggering mechanism is required to create a seed island with finite width before NTMs can grow. The triggers are usually provided by large sawtooth crashes and ELMs. Avoiding NTMs by tailoring sawtooth oscillations has been reported [7]. Controlling NTMs using electron cyclotron heating has been demonstrated in some tokamaks [e.g.,8,9,10], and this method will be utilized on ITER. Alcator C-Mod is a compact (R = 0.68 m, a = 0.22 m) high field (B < 8.1 T ) tokamak, and typically runs with relatively high density compared to other tokamaks. Since NTMs usually occur in higher β and lower collisionality plasmas, they have rarely been observed in the usual

2 2 EX/P4-22 plasma operation parameter space, i.e., L-mode and H-mode plasmas. Several cases have been reported as possible NTM candidates in some high performance Enhanced D α H-mode plasmas in a previous study [11]. In recent experimental campaigns, with the discovery and development of so-called I-mode plasmas [12,13,14], which typically have much lower collisionality (without density pedestal) than H-mode, but have similar energy confinement associated with a T e pedestal, we have started to observe NTMs more frequently on Alcator C- Mod. This paper presents the first systematic characterization of the NTMs observed in Alcator C- Mod. Most of the observations are from experiments that aim at driving large plasma rotations in I-mode. Previously, we have studied flow-drive effect using ICRF mode conversion (MC), and the result showed that the flow drive effect is strongest at low density L-mode plasmas [15,16,17]. I-mode plasmas were thought to be good targets for such flow drive studies, and large rotation was expected by combining the flow drive effect from ICRF and the large intrinsic rotation associated with I-mode (driven by edge T e pedestal [18]). Instead, the result I-mode plasmas frequently show evidence of NTM activities, and the observed plasma rotation is not as large as previously thought. The existence of NTMs in I-mode plasmas also suggests that we will need to find a way to avoid or control NTMs on Alcator C-Mod in order to further develop I-mode as a potential operation scenario of high confinement for future fusion devices. In Section 2, we describe the experimental setup, and in Section 3, we present the characteristics of the observed NTMs, their effects of NTMs on plasma performance and rotation, followed by Discussion (Section 4) and Summary (Section 5). 2. Experimental setup These I-mode experiments were carried out in reversed field (also reversed current) configuration and lower single null shape, that is, the direction of B B drift is toward the top of the machine and away from the divertor. This configuration has been found to favour triggering I-mode and has a wide window of heating power between the L-mode to I-mode transition threshold and the I-mode to H-mode transition threshold [14]. The original aim of the experiment was to study ICRF MC flow drive effect in I-mode plasmas. There are two sets of ICRF antennas on Alcator C-Mod, and each of them is capable of coupling ~3 MW power to the plasma [19,20]. One system is phase variable (+90 o, -90 o, or 180 o ), and also frequency tuneable (50, 70, or 78 MHz). The other system runs at a fixed frequency 80 MHz and fixed 180 o phasing. At +90 o phasing, the launched RF wave is preferentially in the same direction as the plasma current (co-i p ), while -90 o phasing is counter-i p and 180 o phasing (dipole) is toroidally symmetric. In these experiments, with the central magnetic field B t0 ~ 5.1 T, the 80 MHz ICRF was used for central heating via Hydrogen minority heating (with residual H in the plasma), and the antenna at 50 MHz was for 3 He mode conversion heating and flow drive with externally puffed 3 He. Plasma rotation was measured by an x-ray crystal system (HIREX). MHD modes were observed in magnetic coil signals, soft x-ray signals and also ECE T e signals. 3. Characterizing NTMs

3 3 EX/P4-22 A typical plasma in this experiment is shown in Fig. 1. Plasma parameters are I p = 1.0 MA, B t0 = 5.1 T, and n e0 = m -3. In Fig. 1-(d), we show the trace of total ICRF power. We use 50 MHz RF power at 2.5 MW (t > 0.6 sec) to drive plasma central rotation via mode conversion heating to more than 100 km/s as shown in Fig. 1-(e). The plasma stays in L-mode until t = 1.0 sec when we add 2.5 MW RF power at 80 MHz for central heating. The addition of RF power pushes the heating power above the threshold for L-mode to I-mode transition, and the plasma enters the I-mode region, as noted in the strong increase in plasma β in Fig. 1-(c). Fig. 1-(b) shows the central electron temperature trace, which has large sawtooth crashes. Fig. 1-(a) shows MHD modes identified as m = 4, n = 3, and m = 3, n = 2. The modes appear after the rise of β, and also the large sawtooth crashes. The (4, 3) mode appears about 50 ms after the I- mode transition, and later, with the further increase of β, the (3, 2) mode appears. The toroidal rotation does not increase with the I- mode (albeit with doubled stored energy and edge T e pedestal as high as 1 kev), and it actually decreases after the onset of the MHD modes. In these plasmas, because of the high ICRF power and relatively low density, a large population of energetic particles are expected to be generated via the ICRF heating. These energetic particles help stabilize sawtooth oscillations and result in particularly long sawteeth and large crashes. These large sawtooth crashes act as triggers for seeding magnetic islands, from which NTMs can be destabilized and grow. In Fig. 2, we show a detailed view of such a case. A sawtooth crash at 1.12 sec lowered the central T e from 7 kev to 3 kev, and after the sawtooth, an NTM with frequency about 30 khz appears and is sustained for many sawtooth periods. FIG. 1. A typical plasma shot in the experiment. (a) Spectra of a magnetic signal; (b) Central T e ; (c) Toroial and poloidal β; (d)icrf power; (e)central plasma toroidal rotation. L-mode for t < 1.0 sec, and I-mode for t > 1.0 sec. FIG. 2. A large sawtooth crash triggers an NTM. (a) Spectra of a magnetic signal, (b) Data trace of central T e with large sawtooth crashes. The mode numbers are calculated from the magnetic signals from coils in various toroidal locations and poloidal locations. A cross-phase study of the magnetic signals shows the mode in Fig. 2 is best described as mode n = 2 (Fig. 3-(a)) and m = 3 (Fig. 3-(b)). The spatial location of the mode can also be determined from the several ECE channels that observe the mode. The result location, R ~ 0.82 m, is consistent with the location of q = 3/2 surface from

4 4 EX/P4-22 FIG. 3. Mode number calculation for the mode shown in FIG. 2. (a) Cross phase from coils at the same poloidal location but different toroidal locations; (b) Cross phase from coils at the same toroidal location. The best match from the phase from the signals and toroidal/poloidal locations is n = 2, and m = 3. the q profile from EFIT reconstruction. NTMs with other mode numbers can also be determined and verified in the same manner. A variety of modes have been observed, including (5,4), (4,3), (3,2), and (2,1). In some plasmas, (3, 2) mode would appear right away like that in the plasma of Fig. 2, and then possibly (2,1) appears later. In some plasmas, only (5,4) or (4,3) are present. In Fig. 4, we show a plasma that (5,4), (4,3), (3,2), and (2,1) modes all exist in the same shot. The effect to plasma confinement of the NTMs is estimate to be β/β 4(ρ s /a) 4 W sat /ρ s, where ρ s is the minor radius of the island and W sat is the saturated island width [21]. In Fig. 4-(e), the island width is estimated from the magnetic signals using a standard analysis technique [11]. For the (4, 3) mode, W sat ~ cm, and this mode has weak effect. For the (3, 2) mode in these plasmas, W sat ~ cm, and β/β ~ 4-5%. This island width of the (3, 2) mode is approximately 3-4 times the ion banana width, comparable to the observed result from other tokamaks [22]. FIG. 4. A plasma with a variety of NTMs, (a) Spectrl of a magnetic signal, with the mode number of NTMs labelled. (b) Central T e ; (c) Plasma β; (d) ICRF power trace; (e) Island width; (f) Central rotation. The existence of NTMs produces a torque that would slow down the plasma rotation. The torque is generated by the induced field interacting with the machine wall. During the island growing phase, the drag force is W 4 [23]. In Fig. 4-(f) the toroidal rotation is found to

5 5 EX/P4-22 decrease significantly after the NTM onset and along with the growing of the island width. Detailed modelling of torque and rotation will be left for future work. The NTM onset critical conditions have been studied extensively in other tokamaks. Generally, NTMs favour low collisionality and high β. In Fig. 5, we plot the plasma parameters at the time of NTM onset for all the (3, 2) modes, and compare the Alcator C-Mod result with the empirical scaling obtained from ASDEX Upgrade and DIII-D tokamaks [22]. The Alcator C-Mod data are in the range of β P ~ , β N ~ , β N /ρ i * ~ , ν NTM (q=3/2) = (ν ii /ε)/ω e * ~ When β N /ρ i * is plotted vs. ν NTM (q=3/2), the onset critical β is slight lower than that of the other machines while the trend is very similar. In terms of other plasma parameters, e.g., B t, density, plasma rotation and the auxiliary heating source, the C-Mod data occupy a unique parameter space. Further analysis of these data may help clarify some on-going understanding of NTM physics, for example, the effect of plasma rotation on NTM onset critical criteria [24], and the interaction between fast particles and NTMs. FIG. 5. NTM onset criteria for (3,2) mode and compared with data from other machines. NTMs also appear in other I-mode plasmas where only ICRF D(H) minority heating is applied. Fig. 6 shows such a case. Plasma parameters are B t0 = 5.8 T, I p = 1.1 MA, and n e0 = m -3. The onset condition is in a similar range as those with mode conversion flow drive. As shown in Fig. 6-(c), the store FIG. 6. NTMs in I-mode heated only with ICRF minority D(H) heating, (a) Spectra of a magnetic signal; (b) Central T e ; (c)plasma stored energy calculated by EFIT; (d) ICRF power at 80 MHz. energy of the plasma is no longer increasing after the onset of NTMs. Unfortunately, 5 MW is near the limit of the practically available ICRF power, and we are unable to verify whether and/or how effective the NTMs have clamped the plasma performance. 4. Discussion Characterizing the NTMs is only a start in terms of NTM study. We are carrying out experiments aiming at exploring a practical way of avoiding the NTMs in high performance I- mode by tailoring the sawtooth oscillations. Sawteeth can be controlled via ICRF antenna phasing and by carefully manage the relative distance of the q = 1 surface and the ICRF mode conversion surface. These experiments will also determine, if NTMs are avoided in I-mode, whether we can drive significantly more plasma rotation via ICRF mode conversion flow drive. Preliminary results of these experiments will be reported at the conference.

6 6 EX/P Summary NTMs have been observed on Alcator C-Mod in high performance I-mode plasmas. We have characterized the modes, onset criteria and also studied their effect on plasma confinement and rotation. We plan to find a way to avoid or control these modes on Alcator C-Mod in order to further improve plasma performance in I-mode plasmas. Acknowledgments The authors thank the Alcator C-Mod operation and ICRF groups. This work was supported at MIT by U.S. DoE Cooperative Agreement No. DE-FC02-99ER References [1] Chang Z. et al 1995 Phys. Rev. Lett [2] La Haye R. L. et al 1997 Nucl. Fusion [3] Gates D.A. et al 1997 Nucl. Fusion [4] Zohm H. et al 1997 Nucl. Fusion 37 B237 [5] Buttery R.J. et al 1997 Phys. Rev. Lett [6] Huysmans G.T.A. et al 1999 Nucl. Fusion [7] Sauter O. et al 2002 Phys. Rev. Lett [8] Maraschek G. et al 2005 Nucl. Fusion [9] La Haye R.J. et al 2002 Phys. Plasmas [10] La Haye R.J Phys. Plasmas [11] Snipes J.A. et al 2002 Plasma Phys. Control. Fusion [12] Whyte D.G. et al 2010 Nucl. Fusion [13] Hubbard A.E. et al 2011 Phys. Plasmas [14] Hubbard A.E. et al 2012 Presentation EX1-3, this conference. [15] Lin Y. et al 2008 Phys. Rev. Lett [16] Lin Y. et al 2009 Phys. Plasmas [17] Lin Y. et al 2011 Nucl. Fusion [18] Rice J.E. et al 2011 Phys. Rev. Lett [19] Bonoli A., et al 2007 Fusion Sci. Tech [20] Wukitch S. J., et al 2012 Presentation FTP 1-1, this conference [21] Chang Z., et al 1990 Nucl. Fusion [22] La Haye R.J., et al 2000 Phys. Plasmas [23] Nave M.F.F. et al 1990 Nucl. Fusion [24] Sen A Fusion Sci. Tech

ICRF Mode Conversion Flow Drive on the Alcator C Mod Tokamak

ICRF Mode Conversion Flow Drive on the Alcator C Mod Tokamak 23 rd IAEA Fusion Energy Conference, EXW/4 1 ICRF Mode Conversion Flow Drive on the Alcator C Mod Tokamak Yijun Lin, J.E. Rice, S.J. Wukitch, M.L. Reinke, M. Greenwald, A. E. Hubbard, E.S. Marmar, Y. Podpaly,

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

ICRF Mode Conversion Flow Drive on Alcator C-Mod and Projections to Other Tokamaks

ICRF Mode Conversion Flow Drive on Alcator C-Mod and Projections to Other Tokamaks ICRF Mode Conversion Flow Drive on Alcator C-Mod and Projections to Other Tokamaks Y. Lin, J.E. Rice, S.J. Wukitch, M.J. Greenwald, A.E. Hubbard, A. Ince- Cushman, L. Lin, E.S. Marmar, M. Porkolab, M.L.

More information

Local Plasma Parameters and H-Mode Threshold in Alcator C-Mod

Local Plasma Parameters and H-Mode Threshold in Alcator C-Mod PFC/JA-96-42 Local Plasma Parameters and H-Mode Threshold in Alcator C-Mod A.E. Hubbard, J.A. Goetz, I.H. Hutchinson, Y. In, J. Irby, B. LaBombard, P.J. O'Shea, J.A. Snipes, P.C. Stek, Y. Takase, S.M.

More information

On the ρ Scaling of Intrinsic Rotation in C-Mod Plasmas with Edge Transport Barriers

On the ρ Scaling of Intrinsic Rotation in C-Mod Plasmas with Edge Transport Barriers On the ρ Scaling of Intrinsic Rotation in C-Mod Plasmas with Edge Transport Barriers J.E. Rice, J.W. Hughes, P.H. Diamond, N. Cao, M.A. Chilenski, A.E. Hubbard, J.H. Irby, Y. Kosuga Y. Lin, I.W. Metcalf,

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

Pedestal Stability and Transport on the Alcator C-Mod Tokamak: Experiments in Support of Developing Predictive Capability

Pedestal Stability and Transport on the Alcator C-Mod Tokamak: Experiments in Support of Developing Predictive Capability 1 EX/P4-15 Pedestal Stability and Transport on the Alcator C-Mod Tokamak: Experiments in Support of Developing Predictive Capability J.W. Hughes 1, P.B. Snyder 2, X. Xu 3, J.R. Walk 1, E.M. Davis 1, R.M.

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

The role of stochastization in fast MHD phenomena on ASDEX Upgrade

The role of stochastization in fast MHD phenomena on ASDEX Upgrade 1 EX/P9-10 The role of stochastization in fast MHD phenomena on ASDEX Upgrade V. Igochine 1), O.Dumbrajs 2,3), H. Zohm 1), G. Papp 4), G. Por 4), G. Pokol 4), ASDEX Upgrade team 1) 1) MPI für Plasmaphysik,

More information

ITB Transport Studies in Alcator C-Mod. Catherine Fiore MIT Plasma Science and Fusion Center Transport Task Force March 26th Boulder, Co

ITB Transport Studies in Alcator C-Mod. Catherine Fiore MIT Plasma Science and Fusion Center Transport Task Force March 26th Boulder, Co Transport Studies in Alcator C-Mod Catherine Fiore MIT Plasma Science and Fusion Center Transport Task Force March 26th Boulder, Co With Contributions from: I. Bespamyatnov, P. T. Bonoli*, D. Ernst*, M.

More information

Developing the Physics Basis for the ITER Baseline 15 MA Scenario in Alcator C-Mod

Developing the Physics Basis for the ITER Baseline 15 MA Scenario in Alcator C-Mod Developing the Physics Basis for the ITER Baseline 15 MA Scenario in Alcator C-Mod C. E. Kessel 1, S. M. Wolfe 2, I. H. Hutchinson 2, J. W. Hughes 2, Y. Lin 2, Y. Ma 2, D. R. Mikkelsen 1, F. M. Poli 1,

More information

OV/2-5: Overview of Alcator C-Mod Results

OV/2-5: Overview of Alcator C-Mod Results OV/2-5: Overview of Alcator C-Mod Results Research in Support of ITER and Steps Beyond* E.S. Marmar on behalf of the C-Mod Team 25 th IAEA Fusion Energy Conference, Saint Petersburg, Russia, 13 October,

More information

Performance limits. Ben Dudson. 24 th February Department of Physics, University of York, Heslington, York YO10 5DD, UK

Performance limits. Ben Dudson. 24 th February Department of Physics, University of York, Heslington, York YO10 5DD, UK Performance limits Ben Dudson Department of Physics, University of York, Heslington, York YO10 5DD, UK 24 th February 2014 Ben Dudson Magnetic Confinement Fusion (1 of 24) Previously... In the last few

More information

Active and Fast Particle Driven Alfvén Eigenmodes in Alcator C-Mod

Active and Fast Particle Driven Alfvén Eigenmodes in Alcator C-Mod Active and Fast Particle Driven Alfvén Eigenmodes in Alcator C-Mod JUST DID IT. J A Snipes, N Basse, C Boswell, E Edlund, A Fasoli #, N N Gorelenkov, R S Granetz, L Lin, Y Lin, R Parker, M Porkolab, J

More information

Spontaneous Core Toroidal Rotation in Alcator C- Mod L-Mode, H-Mode and ITB Plasmas.

Spontaneous Core Toroidal Rotation in Alcator C- Mod L-Mode, H-Mode and ITB Plasmas. PSFC/JA-8-11 Spontaneous Core Toroidal Rotation in Alcator C- Mod L-Mode, H-Mode and ITB Plasmas. Rice, J.E.; Ince-Cushman, A.C.; Reinke, M.L.; Podpaly, Y.; Greenwald, M.J.; LaBombard, B.S.; Marmar, E.S.

More information

EXC/P2-02. Experiments and Simulations of ITER-like Plasmas in Alcator C-Mod

EXC/P2-02. Experiments and Simulations of ITER-like Plasmas in Alcator C-Mod EXC/P2-02 Experiments and Simulations of ITER-like Plasmas in Alcator C-Mod J. R. Wilson 1, C. E. Kessel 1, S. Wolfe 2, I. Hutchinson 2, P. Bonoli 2, C. Fiore 2, A. Hubbard 2, J. Hughes 2, Y. Lin 2, Y.

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

The performance of improved H-modes at ASDEX Upgrade and projection to ITER

The performance of improved H-modes at ASDEX Upgrade and projection to ITER EX/1-1 The performance of improved H-modes at ASDEX Upgrade and projection to George Sips MPI für Plasmaphysik, EURATOM-Association, D-85748, Germany G. Tardini 1, C. Forest 2, O. Gruber 1, P. Mc Carthy

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

Investigation of Intrinsic Rotation Dependencies in Alcator C-Mod

Investigation of Intrinsic Rotation Dependencies in Alcator C-Mod Investigation of Intrinsic Rotation Dependencies in Alcator C-Mod D. Kwak, A. E. White, J. E. Rice, N. T. Howard, C. Gao, M. L. Reinke, M. Greenwald, C. Angioni, R. M. McDermott, and the C-Mod and ASDEX

More information

Recent results from lower hybrid current drive experiments on Alcator C-Mod

Recent results from lower hybrid current drive experiments on Alcator C-Mod Recent results from lower hybrid current drive experiments on Alcator C-Mod R. R. Parker, S.-G. Baek, C. Lau, Y. Ma, O. Meneghini, R. T. Mumgaard, Y. Podpaly, M. Porkolab, J.E. Rice, A. E. Schmidt, S.

More information

Improved RF Actuator Schemes for the Lower Hybrid and the Ion Cyclotron Range of Frequencies in Reactor-Relevant Plasmas

Improved RF Actuator Schemes for the Lower Hybrid and the Ion Cyclotron Range of Frequencies in Reactor-Relevant Plasmas Improved RF Actuator Schemes for the Lower Hybrid and the Ion Cyclotron Range of Frequencies in Reactor-Relevant Plasmas P. T. Bonoli*, S. G. Baek, B. LaBombard, K. Filar, M. Greenwald, R. Leccacorvi,

More information

Enhanced Energy Confinement Discharges with L-mode-like Edge Particle Transport*

Enhanced Energy Confinement Discharges with L-mode-like Edge Particle Transport* Enhanced Energy Confinement Discharges with L-mode-like Edge Particle Transport* E. Marmar, B. Lipschultz, A. Dominguez, M. Greenwald, N. Howard, A. Hubbard, J. Hughes, B. LaBombard, R. McDermott, M. Reinke,

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

THE DIII D PROGRAM THREE-YEAR PLAN

THE DIII D PROGRAM THREE-YEAR PLAN THE PROGRAM THREE-YEAR PLAN by T.S. Taylor Presented to Program Advisory Committee Meeting January 2 21, 2 3 /TST/wj PURPOSE OF TALK Show that the program plan is appropriate to meet the goals and is well-aligned

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

Ohmic and RF Heated ITBs in Alcator C-Mod

Ohmic and RF Heated ITBs in Alcator C-Mod Ohmic and RF Heated s in Alcator C-Mod William L. Rowan, Igor O. Bespamyatnov Fusion Research Center, The University of Texas at Austin C.L. Fiore, A. Dominguez, A.E. Hubbard, A. Ince-Cushman, M.J. Greenwald,

More information

Observation of Co- and Counter Rotation Produced by Lower Hybrid Waves in Alcator C-Mod*

Observation of Co- and Counter Rotation Produced by Lower Hybrid Waves in Alcator C-Mod* Observation of Co- and Counter Rotation Produced by Lower Hybrid Waves in Alcator C-Mod* R. R. Parker, Y. Podpaly, J. Lee, M. L. Reinke, J. E. Rice, P.T. Bonoli, O. Meneghini, S. Shiraiwa, G. M. Wallace,

More information

Alcator C-Mod. Double Transport Barrier Plasmas. in Alcator C-Mod. J.E. Rice for the C-Mod Group. MIT PSFC, Cambridge, MA 02139

Alcator C-Mod. Double Transport Barrier Plasmas. in Alcator C-Mod. J.E. Rice for the C-Mod Group. MIT PSFC, Cambridge, MA 02139 Alcator C-Mod Double Transport Barrier Plasmas in Alcator C-Mod J.E. Rice for the C-Mod Group MIT PSFC, Cambridge, MA 139 IAEA Lyon, Oct. 17, Outline Double Barrier Plasma Profiles and Modeling Conditions

More information

Active and Passive MHD Spectroscopy on Alcator C-Mod

Active and Passive MHD Spectroscopy on Alcator C-Mod Active and Passive MHD Spectroscopy on Alcator C-Mod J A Snipes, D A Schmittdiel, C Boswell, A Fasoli *, W Burke, R S Granetz, R R Parker, S Sharapov #, R Vieira MIT Plasma Science and Fusion Center, Cambridge,

More information

ICRF Induced Argon Pumpout in H-D Plasmas in Alcator C-Mod

ICRF Induced Argon Pumpout in H-D Plasmas in Alcator C-Mod ICRF Induced Argon Pumpout in H-D Plasmas in Alcator C-Mod C. Gao, J.E. Rice, M.L. Reinke, Y. Lin, S.J. Wukitch, L. Delgado-Aparicio, E.S. Marmar, and Alcator C-Mod Team MIT-PSFC, University of York, Princeton

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

Predicting the Rotation Profile in ITER

Predicting the Rotation Profile in ITER Predicting the Rotation Profile in ITER by C. Chrystal1 in collaboration with B. A. Grierson2, S. R. Haskey2, A. C. Sontag3, M. W. Shafer3, F. M. Poli2, and J. S. degrassie1 1General Atomics 2Princeton

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

Helium ELMy H-modes in Alcator C-Mod in Support of ITER Helium Operating Phases

Helium ELMy H-modes in Alcator C-Mod in Support of ITER Helium Operating Phases Helium ELMy H-modes in Alcator C-Mod in Support of ITER Helium Operating Phases C. E. Kessel 1, S. M. Wolfe 2, M. L. Reinke 3, M. A. Chilenski 2, J. W. Hughes 2, Y. Lin 2, S. Wukitch 2 and the C-Mod Team

More information

TOKAMAK EXPERIMENTS - Summary -

TOKAMAK EXPERIMENTS - Summary - 17 th IAEA Fusion Energy Conference, Yokohama, October, 1998 TOKAMAK EXPERIMENTS - Summary - H. KISHIMOTO Japan Atomic Energy Research Institute 2-2 Uchisaiwai-Cho, Chiyoda-Ku, Tokyo, Japan 1. Introduction

More information

ELM Suppression in DIII-D Hybrid Plasmas Using n=3 Resonant Magnetic Perturbations

ELM Suppression in DIII-D Hybrid Plasmas Using n=3 Resonant Magnetic Perturbations 1 EXC/P5-02 ELM Suppression in DIII-D Hybrid Plasmas Using n=3 Resonant Magnetic Perturbations B. Hudson 1, T.E. Evans 2, T.H. Osborne 2, C.C. Petty 2, and P.B. Snyder 2 1 Oak Ridge Institute for Science

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

OVERVIEW OF THE ALCATOR C-MOD PROGRAM. IAEA-FEC November, 2004 Alcator Team Presented by Martin Greenwald MIT Plasma Science & Fusion Center

OVERVIEW OF THE ALCATOR C-MOD PROGRAM. IAEA-FEC November, 2004 Alcator Team Presented by Martin Greenwald MIT Plasma Science & Fusion Center OVERVIEW OF THE ALCATOR C-MOD PROGRAM IAEA-FEC November, 2004 Alcator Team Presented by Martin Greenwald MIT Plasma Science & Fusion Center OUTLINE C-Mod is compact, high field, high density, high power

More information

ICRF Minority-Heated Fast-Ion Distributions on the Alcator C-Mod: Experiment and Simulation

ICRF Minority-Heated Fast-Ion Distributions on the Alcator C-Mod: Experiment and Simulation ICRF Minority-Heated Fast-Ion Distributions on the Alcator C-Mod: Experiment and Simulation A. Bader 1, P. Bonoli 1, R. Granetz 1, R.W. Harvey 2, E.F. Jaeger 3, R. Parker 1, S. Wukitch 1. 1)MIT-PSFC, Cambridge,

More information

MHD. Jeff Freidberg MIT

MHD. Jeff Freidberg MIT MHD Jeff Freidberg MIT 1 What is MHD MHD stands for magnetohydrodynamics MHD is a simple, self-consistent fluid description of a fusion plasma Its main application involves the macroscopic equilibrium

More information

Macroscopic Stability Research Program on Alcator C-Mod

Macroscopic Stability Research Program on Alcator C-Mod Macroscopic Stability Research Program on Alcator C-Mod Presented by R. Granetz Alcator C-Mod PAC 04-06 Feb 2009 Principal areas of MHD research on C-Mod Disruptions and disruption mitigation, including

More information

Study of Enhanced D α H-modes Using the Alcator C-Mod Reflectometer

Study of Enhanced D α H-modes Using the Alcator C-Mod Reflectometer Study of Enhanced D α H-modes Using the Reflectometer Y. Lin 1, J.H. Irby, E.S. Marmar, R. Nazikian, M. Greenwald, A.E. Hubbard, J. Hughes, I.H. Hutchinson, B. LaBombard, A. Mazurenko, E. Nelson-Melby,

More information

Studies of Lower Hybrid Range of Frequencies Actuators in the ARC Device

Studies of Lower Hybrid Range of Frequencies Actuators in the ARC Device Studies of Lower Hybrid Range of Frequencies Actuators in the ARC Device P. T. Bonoli, Y. Lin. S. Shiraiwa, G. M. Wallace, J. C. Wright, and S. J. Wukitch MIT PSFC, Cambridge, MA 02139 59th Annual Meeting

More information

PROGRESS TOWARDS SUSTAINMENT OF ADVANCED TOKAMAK MODES IN DIIIÐD *

PROGRESS TOWARDS SUSTAINMENT OF ADVANCED TOKAMAK MODES IN DIIIÐD * PROGRESS TOWARDS SUSTAINMENT OF ADVANCED TOKAMAK MODES IN DIIIÐD * B.W. RICE, K.H. BURRELL, J.R. FERRON, C.M. GREENFIELD, G.L. JACKSON, L.L. LAO, R.J. LA HAYE, T.C. LUCE, B.W. STALLARD, E.J. STRAIT, E.J.

More information

(Motivation) Reactor tokamaks have to run without disruptions

(Motivation) Reactor tokamaks have to run without disruptions Abstract A database has been developed to study the evolution, the nonlinear effects on equilibria, and the disruptivity of locked and quasi-stationary modes with poloidal and toroidal mode numbers m=2

More information

Formation and stability of impurity snakes in tokamak plasmas

Formation and stability of impurity snakes in tokamak plasmas PSFC/JA--9 Formation and stability of impurity snakes in tokamak plasmas L. Delgado-Aparicio,, L. Sugiyama, R. Granetz, J. Rice, Y. Podpaly, M. Reinke, D. Gates, P. Beirsdorfer 4, M. Bitter, S. Wolfe,

More information

GA A23403 GAS PUFF FUELED H MODE DISCHARGES WITH GOOD ENERGY CONFINEMENT ABOVE THE GREENWALD DENSITY LIMIT ON DIII D

GA A23403 GAS PUFF FUELED H MODE DISCHARGES WITH GOOD ENERGY CONFINEMENT ABOVE THE GREENWALD DENSITY LIMIT ON DIII D GA A23403 GAS PUFF FUELED H MODE DISCHARGES WITH GOOD ENERGY CONFINEMENT ABOVE THE GREENWALD DENSITY LIMIT ON DIII D by T.H. OSBORNE, M.A. MAHDAVI, M.S. CHU, M.E. FENSTERMACHER, R.J. La HAYE, A.W. LEONARD,

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

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

Poloidal Variation of High-Z Impurity Density in ICRF- Heated Alcator C-Mod Plasmas

Poloidal Variation of High-Z Impurity Density in ICRF- Heated Alcator C-Mod Plasmas Poloidal Variation of High-Z Impurity Density in ICRF- Heated Alcator C-Mod Plasmas M.L. Reinke, I.H. Hutchinson, J.E. Rice, N.T. Howard, A. Bader, S. Wukitch, Y. Lin, D.C. Pace, A. Hubbard, J.W. Hughes

More information

Radial impurity transport in the H mode transport barrier region in Alcator C-Mod

Radial impurity transport in the H mode transport barrier region in Alcator C-Mod Radial impurity transport in the H mode transport barrier region in Alcator C-Mod T. Sunn Pedersen, R.S. Granetz, A.E. Hubbard, I.H. Hutchinson, E.S. Marmar, J.E. Rice, J. Terry Plasma Science and Fusion

More information

ICRF Loading Studies on Alcator C-Mod

ICRF Loading Studies on Alcator C-Mod ICRF Loading Studies on Alcator C-Mod 46 th Annual Meeting of the APS Division of Plasma Physics November 15-19, 19, 2004 A. Parisot, S.J. S.J. Wukitch,, P. Bonoli,, J.W. Hughes, B. Labombard,, Y. Lin,

More information

Overview of Recent Results from Alcator C-Mod including Applications to ITER Scenarios

Overview of Recent Results from Alcator C-Mod including Applications to ITER Scenarios Overview of Recent Results from Alcator C-Mod including Applications to ITER Scenarios E. S. Marmar and the Alcator C-Mod Team MIT Plasma Science and Fusion Center, Cambridge MA 02139 USA E-mail contact

More information

Lower Hybrid Wave Induced Rotation on Alcator C-Mod* Ron Parker, Yuri Podpaly, John Rice, Andréa Schmidt

Lower Hybrid Wave Induced Rotation on Alcator C-Mod* Ron Parker, Yuri Podpaly, John Rice, Andréa Schmidt Lower Hybrid Wave Induced Rotation on Alcator C-Mod* Ron Parker, Yuri Podpaly, John Rice, Andréa Schmidt *Work supported by USDoE awards DE-FC-99ER551 and DE-AC-7CH373 Abstract Injection of RF power in

More information

Pedestals and Fluctuations in C-Mod Enhanced D α H-modes

Pedestals and Fluctuations in C-Mod Enhanced D α H-modes Pedestals and Fluctuations in Enhanced D α H-modes Presented by A.E.Hubbard With Contributions from R.L. Boivin, B.A. Carreras 1, S. Gangadhara, R. Granetz, M. Greenwald, J. Hughes, I. Hutchinson, J. Irby,

More information

ELMs and Constraints on the H-Mode Pedestal:

ELMs and Constraints on the H-Mode Pedestal: ELMs and Constraints on the H-Mode Pedestal: A Model Based on Peeling-Ballooning Modes P.B. Snyder, 1 H.R. Wilson, 2 J.R. Ferron, 1 L.L. Lao, 1 A.W. Leonard, 1 D. Mossessian, 3 M. Murakami, 4 T.H. Osborne,

More information

n=1 RESISTIVE MODES in REVERSED MAGNETIC SHEAR ALCATOR C-MOD PLASMAS

n=1 RESISTIVE MODES in REVERSED MAGNETIC SHEAR ALCATOR C-MOD PLASMAS October 10, 2000 n=1 RESISTIVE MODES in REVERSED MAGNETIC SHEAR ALCATOR C-MOD PLASMAS Y. IN, J.J.RAMOS, A.E.HUBBARD, I.H.HUTCHINSON, M. PORKOLAB, J. SNIPES, S. WOLFE, A. BONDESON MIT Plasma Science and

More information

TRANSPORT PROGRAM C-MOD 5 YEAR REVIEW MAY, 2003 PRESENTED BY MARTIN GREENWALD MIT PLASMA SCIENCE & FUSION CENTER

TRANSPORT PROGRAM C-MOD 5 YEAR REVIEW MAY, 2003 PRESENTED BY MARTIN GREENWALD MIT PLASMA SCIENCE & FUSION CENTER TRANSPORT PROGRAM C-Mod C-MOD 5 YEAR REVIEW MAY, 2003 PRESENTED BY MARTIN GREENWALD MIT PLASMA SCIENCE & FUSION CENTER C-MOD - OPPORTUNITIES AND CHALLENGES Prediction and control are the ultimate goals

More information

Electron Transport and Improved Confinement on Tore Supra

Electron Transport and Improved Confinement on Tore Supra Electron Transport and Improved Confinement on Tore Supra G. T. Hoang, C. Bourdelle, X. Garbet, T. Aniel, G. Giruzzi, M. Ottaviani. Association EURATOM-CEA. CEA-Cadarache, 38, St Paul-lez-Durance, France

More information

1999 RESEARCH SUMMARY

1999 RESEARCH SUMMARY 1999 RESEARCH SUMMARY by S.L. Allen Presented to DIII D Program Advisory Committee Meeting January 2 21, 2 DIII D NATIONAL FUSION FACILITY SAN DIEGO 3 /SLA/wj Overview of Physics Results from the 1999

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

Formation and Long Term Evolution of an Externally Driven Magnetic Island in Rotating Plasmas )

Formation and Long Term Evolution of an Externally Driven Magnetic Island in Rotating Plasmas ) Formation and Long Term Evolution of an Externally Driven Magnetic Island in Rotating Plasmas ) Yasutomo ISHII and Andrei SMOLYAKOV 1) Japan Atomic Energy Agency, Ibaraki 311-0102, Japan 1) University

More information

GA A22443 STUDY OF H MODE THRESHOLD CONDITIONS IN DIII D

GA A22443 STUDY OF H MODE THRESHOLD CONDITIONS IN DIII D GA A443 STUDY OF H MODE THRESHOLD CONDITIONS IN DIII D by R.J. GROEBNER, T.N. CARLSTROM, K.H. BURRELL, S. CODA, E.J. DOYLE, P. GOHIL, K.W. KIM, Q. PENG, R. MAINGI, R.A. MOYER, C.L. RETTIG, T.L. RHODES,

More information

Confinement and Transport Research in Alcator C-Mod

Confinement and Transport Research in Alcator C-Mod PSFC/JA-05-32. Confinement and Transport Research in Alcator C-Mod M. Greenwald, N. Basse, P. Bonoli, R. Bravenec 1, E. Edlund, D. Ernst, C. Fiore, R. Granetz, A. Hubbard, J. Hughes, I. Hutchinson, J.

More information

GA A22571 REDUCTION OF TOROIDAL ROTATION BY FAST WAVE POWER IN DIII D

GA A22571 REDUCTION OF TOROIDAL ROTATION BY FAST WAVE POWER IN DIII D GA A22571 REDUCTION OF TOROIDAL ROTATION BY FAST WAVE POWER IN DIII D by J.S. degrassie, D.R. BAKER, K.H. BURRELL, C.M. GREENFIELD, H. IKEZI, Y.R. LIN-LIU, C.C. PETTY, and R. PRATER APRIL 1997 This report

More information

ITER operation. Ben Dudson. 14 th March Department of Physics, University of York, Heslington, York YO10 5DD, UK

ITER operation. Ben Dudson. 14 th March Department of Physics, University of York, Heslington, York YO10 5DD, UK ITER operation Ben Dudson Department of Physics, University of York, Heslington, York YO10 5DD, UK 14 th March 2014 Ben Dudson Magnetic Confinement Fusion (1 of 18) ITER Some key statistics for ITER are:

More information

NIMROD FROM THE CUSTOMER S PERSPECTIVE MING CHU. General Atomics. Nimrod Project Review Meeting July 21 22, 1997

NIMROD FROM THE CUSTOMER S PERSPECTIVE MING CHU. General Atomics. Nimrod Project Review Meeting July 21 22, 1997 NIMROD FROM THE CUSTOMER S PERSPECTIVE MING CHU General Atomics Nimrod Project Review Meeting July 21 22, 1997 Work supported by the U.S. Department of Energy under Grant DE-FG03-95ER54309 and Contract

More information

PHYSICS OF CFETR. Baonian Wan for CFETR physics group Institute of Plasma Physcis, Chinese Academy of Sciences, Hefei, China.

PHYSICS OF CFETR. Baonian Wan for CFETR physics group Institute of Plasma Physcis, Chinese Academy of Sciences, Hefei, China. PHYSICS OF CFETR Baonian Wan for CFETR physics group Institute of Plasma Physcis, Chinese Academy of Sciences, Hefei, China Dec 4, 2013 Mission of CFETR Complementary with ITER Demonstration of fusion

More information

Macroscopic Stability Research on Alcator C-Mod: 5-year plan

Macroscopic Stability Research on Alcator C-Mod: 5-year plan Macroscopic Stability Research on Alcator C-Mod: 5-year plan Presented by R. Granetz Alcator C-Mod PAC 06-08 Feb 2008 Principal MHD Research Topics in the Next 5-year Plan Effects of non-axisymmetric fields

More information

W.A. HOULBERG Oak Ridge National Lab., Oak Ridge, TN USA. M.C. ZARNSTORFF Princeton Plasma Plasma Physics Lab., Princeton, NJ USA

W.A. HOULBERG Oak Ridge National Lab., Oak Ridge, TN USA. M.C. ZARNSTORFF Princeton Plasma Plasma Physics Lab., Princeton, NJ USA INTRINSICALLY STEADY STATE TOKAMAKS K.C. SHAING, A.Y. AYDEMIR, R.D. HAZELTINE Institute for Fusion Studies, The University of Texas at Austin, Austin TX 78712 USA W.A. HOULBERG Oak Ridge National Lab.,

More information

The non-resonant kink modes triggering strong sawtooth-like crashes. in the EAST tokamak. and L. Hu 1

The non-resonant kink modes triggering strong sawtooth-like crashes. in the EAST tokamak. and L. Hu 1 The non-resonant kink modes triggering strong sawtooth-like crashes in the EAST tokamak Erzhong Li 1, V. Igochine 2, O. Dumbrajs 3, L. Xu 1, K. Chen 1, T. Shi 1, and L. Hu 1 1 Institute of Plasma Physics,

More information

Reduction of Turbulence and Transport in the Alcator C-Mod Tokamak by Dilution of Deuterium Ions with Nitrogen and Neon Injection

Reduction of Turbulence and Transport in the Alcator C-Mod Tokamak by Dilution of Deuterium Ions with Nitrogen and Neon Injection Reduction of Turbulence and Transport in the Alcator C-Mod Tokamak by Dilution of Deuterium Ions with Nitrogen and Neon Injection M. Porkolab, P. C. Ennever, S. G. Baek, E. M. Edlund, J. Hughes, J. E.

More information

Overview of Alcator C-Mod Research

Overview of Alcator C-Mod Research Overview of C-Mod Research Presented by E.S. Marmar On behalf of the C-Mod Team APS-DPP04 Paper JO3.001 Work Supported by USDoE Office of Fusion Energy Sciences SOL flows impose a toroidal rotation boundary

More information

Low-collisionality density-peaking in GYRO simulations of C-Mod plasmas

Low-collisionality density-peaking in GYRO simulations of C-Mod plasmas Low-collisionality density-peaking in GYRO simulations of C-Mod plasmas D. R. Mikkelsen, M. Bitter, K. Hill, PPPL M. Greenwald, J.W. Hughes, J. Rice, MIT J. Candy, R. Waltz, General Atomics APS Division

More information

Correlation Between Plasma Rotation and Electron Temperature Gradient Scale Length in LOC/SOC Transition at Alcator C-Mod

Correlation Between Plasma Rotation and Electron Temperature Gradient Scale Length in LOC/SOC Transition at Alcator C-Mod Correlation Between Plasma Rotation and Electron Temperature Gradient Scale Length in LOC/SOC Transition at Alcator C-Mod Saeid Houshmandyar 1 W. L. Rowan, 1 P. E. Phillips, 1 M. J. Greenwald, 2 J. W.

More information

Progressing Performance Tokamak Core Physics. Marco Wischmeier Max-Planck-Institut für Plasmaphysik Garching marco.wischmeier at ipp.mpg.

Progressing Performance Tokamak Core Physics. Marco Wischmeier Max-Planck-Institut für Plasmaphysik Garching marco.wischmeier at ipp.mpg. Progressing Performance Tokamak Core Physics Marco Wischmeier Max-Planck-Institut für Plasmaphysik 85748 Garching marco.wischmeier at ipp.mpg.de Joint ICTP-IAEA College on Advanced Plasma Physics, Triest,

More information

Spontaneous tokamak rotation: observations turbulent momentum transport has to explain

Spontaneous tokamak rotation: observations turbulent momentum transport has to explain Spontaneous tokamak rotation: observations turbulent momentum transport has to explain Ian H Hutchinson Plasma Science and Fusion Center and Nuclear Science and Engineering Massachusetts Institute of Technology

More information

I-mode and H-mode plasmas at high magnetic field and pressure on Alcator C-Mod

I-mode and H-mode plasmas at high magnetic field and pressure on Alcator C-Mod I-mode and H-mode plasmas at high magnetic field and pressure on Alcator C-Mod A. E. Hubbard, J. W Hughes, S.-G. Baek, D. Brunner, I. Cziegler 1, E. Edlund, T. Golfinopoulos, M.J. Greenwald, J. Irby, B.

More information

Neoclassical Tearing Modes

Neoclassical Tearing Modes Neoclassical Tearing Modes O. Sauter 1, H. Zohm 2 1 CRPP-EPFL, Lausanne, Switzerland 2 Max-Planck-Institut für Plasmaphysik, Garching, Germany Physics of ITER DPG Advanced Physics School 22-26 Sept, 2014,

More information

Physics Basis of ITER-FEAT

Physics Basis of ITER-FEAT IAEA-CN-77/ITERP/05 Physics Basis of ITER-FEAT M. Shimada 1), D. J. Campbell 2), M. Wakatani 3), H. Ninomiya 4), N. Ivanov 5), V. Mukhovatov 1) and the ITER Joint Central Team and Home Teams 1) ITER Joint

More information

H-mode performance and pedestal studies with enhanced particle control on Alcator C-Mod

H-mode performance and pedestal studies with enhanced particle control on Alcator C-Mod H-mode performance and pedestal studies with enhanced particle control on Alcator C-Mod J.W. Hughes, B. LaBombard, M. Greenwald, A. Hubbard, B. Lipschultz, K. Marr, R. McDermott, M. Reinke, J.L. Terry

More information

Effect of ideal kink instabilities on particle redistribution

Effect of ideal kink instabilities on particle redistribution Effect of ideal kink instabilities on particle redistribution H. E. Ferrari1,2,R. Farengo1, P. L. Garcia-Martinez2, M.-C. Firpo3, A. F. Lifschitz4 1 Comisión Nacional de Energía Atómica, Centro Atomico

More information

First Observation of ELM Suppression by Magnetic Perturbations in ASDEX Upgrade and Comparison to DIII-D Matched-Shape Plasmas

First Observation of ELM Suppression by Magnetic Perturbations in ASDEX Upgrade and Comparison to DIII-D Matched-Shape Plasmas 1 PD/1-1 First Observation of ELM Suppression by Magnetic Perturbations in ASDEX Upgrade and Comparison to DIII-D Matched-Shape Plasmas R. Nazikian 1, W. Suttrop 2, A. Kirk 3, M. Cavedon 2, T.E. Evans

More information

Integrated Simulation of ELM Energy Loss Determined by Pedestal MHD and SOL Transport

Integrated Simulation of ELM Energy Loss Determined by Pedestal MHD and SOL Transport 1 Integrated Simulation of ELM Energy Loss Determined by Pedestal MHD and SOL Transport N. Hayashi, T. Takizuka, T. Ozeki, N. Aiba, N. Oyama Japan Atomic Energy Agency, Naka, Ibaraki-ken, 311-0193 Japan

More information

DEPENDENCE OF THE H-MODE PEDESTAL STRUCTURE ON ASPECT RATIO

DEPENDENCE OF THE H-MODE PEDESTAL STRUCTURE ON ASPECT RATIO 21 st IAEA Fusion Energy Conference Chengdu, China Oct. 16-21, 2006 DEPENDENCE OF THE H-MODE PEDESTAL STRUCTURE ON ASPECT RATIO R. Maingi 1, A. Kirk 2, T. Osborne 3, P. Snyder 3, S. Saarelma 2, R. Scannell

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

A New Resistive Response to 3-D Fields in Low Rotation H-modes

A New Resistive Response to 3-D Fields in Low Rotation H-modes in Low Rotation H-modes by Richard Buttery 1 with Rob La Haye 1, Yueqiang Liu 2, Bob Pinsker 1, Jong-kyu Park 3, Holger Reimerdes 4, Ted Strait 1, and the DIII-D research team. 1 General Atomics, USA 2

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

The EPED Pedestal Model: Extensions, Application to ELM-Suppressed Regimes, and ITER Predictions

The EPED Pedestal Model: Extensions, Application to ELM-Suppressed Regimes, and ITER Predictions The EPED Pedestal Model: Extensions, Application to ELM-Suppressed Regimes, and ITER Predictions P.B. Snyder 1, T.H. Osborne 1, M.N.A. Beurskens 2, K.H. Burrell 1, R.J. Groebner 1, J.W. Hughes 3, R. Maingi

More information

Tungsten impurity transport experiments in Alcator C-Mod to address high priority R&D for ITER

Tungsten impurity transport experiments in Alcator C-Mod to address high priority R&D for ITER Tungsten impurity transport experiments in Alcator C-Mod to address high priority R&D for ITER M.L. Reinke 1, A. Loarte 2, M. Chilenski 3, N. Howard 3, F. Köchl 4, A. Polevoi 2, A. Hubbard 3, J.W. Hughes

More information

MHD Analysis of the Tokamak Edge Pedestal in the Low Collisionality Regime Thoughts on the Physics of ELM-free QH and RMP Discharges

MHD Analysis of the Tokamak Edge Pedestal in the Low Collisionality Regime Thoughts on the Physics of ELM-free QH and RMP Discharges MHD Analysis of the Tokamak Edge Pedestal in the Low Collisionality Regime Thoughts on the Physics of ELM-free QH and RMP Discharges P.B. Snyder 1 Contributions from: H.R. Wilson 2, D.P. Brennan 1, K.H.

More information

Role of Magnetic Configuration and Heating Power in ITB Formation in JET.

Role of Magnetic Configuration and Heating Power in ITB Formation in JET. Role of Magnetic Configuration and Heating Power in ITB Formation in JET. The JET Team (presented by V. Parail 1 ) JET Joint Undertaking, Abingdon, Oxfordshire, United Kingdom 1 present address: EURATOM/UKAEA

More information

Influence of Beta, Shape and Rotation on the H-mode Pedestal Height

Influence of Beta, Shape and Rotation on the H-mode Pedestal Height Influence of Beta, Shape and Rotation on the H-mode Pedestal Height by A.W. Leonard with R.J. Groebner, T.H. Osborne, and P.B. Snyder Presented at Forty-Ninth APS Meeting of the Division of Plasma Physics

More information

GA A25351 PHYSICS ADVANCES IN THE ITER HYBRID SCENARIO IN DIII-D

GA A25351 PHYSICS ADVANCES IN THE ITER HYBRID SCENARIO IN DIII-D GA A25351 PHYSICS ADVANCES IN THE ITER HYBRID SCENARIO IN DIII-D by C.C. PETTY, P.A. POLITZER, R.J. JAYAKUMAR, T.C. LUCE, M.R. WADE, M.E. AUSTIN, D.P. BRENNAN, T.A. CASPER, M.S. CHU, J.C. DeBOO, E.J. DOYLE,

More information

EX/P3-31. Scalings of Spontaneous Rotation in the JET Tokamak

EX/P3-31. Scalings of Spontaneous Rotation in the JET Tokamak 1 Scalings of Spontaneous Rotation in the JET Tokamak M. F. F. Nave 1, L.-G. Eriksson, C. Giroud 3, J. S. de Grassie 4, T. Hellsten,T. Johnson, K, Kirov 3,Y. Lin 6, J. Mailoux 3, P. Mantica 11, M.-L. Mayoral

More information

(a) (b) (c) (d) (e) (f) r (minor radius) time. time. Soft X-ray. T_e contours (ECE) r (minor radius) time time

(a) (b) (c) (d) (e) (f) r (minor radius) time. time. Soft X-ray. T_e contours (ECE) r (minor radius) time time Studies of Spherical Tori, Stellarators and Anisotropic Pressure with M3D 1 L.E. Sugiyama 1), W. Park 2), H.R. Strauss 3), S.R. Hudson 2), D. Stutman 4), X-Z. Tang 2) 1) Massachusetts Institute of Technology,

More information

Non-local Heat Transport, Core Rotation Reversals and Energy Confinement Saturation in Alcator C-Mod Ohmic L-mode Plasmas

Non-local Heat Transport, Core Rotation Reversals and Energy Confinement Saturation in Alcator C-Mod Ohmic L-mode Plasmas 1 EX/2-2 Non-local Heat Transport, Core Rotation Reversals and Energy Confinement Saturation in Alcator C-Mod Ohmic L-mode Plasmas J.E. Rice 1, M.L. Reinke 1, H.J. Sun 2, P.H. Diamond 3,4, C. Gao 1, N.T.

More information

ICRF Induced Argon Pumpout in H-D Plasmas at Alcator C-Mod

ICRF Induced Argon Pumpout in H-D Plasmas at Alcator C-Mod 0 ICRF Induced Argon Pumpout in H-D Plasmas at Alcator C-Mod C Gao J.E. Rice, M.L. Reinke, S.J. Wukitch, Y. Lin and Alcator C-Mod Team MIT-PSFC October 29, 2014 C Gao etc., MIT-PSFC 56th APS-DPP New Orleans,

More information

Characteristics of the H-mode H and Extrapolation to ITER

Characteristics of the H-mode H and Extrapolation to ITER Characteristics of the H-mode H Pedestal and Extrapolation to ITER The H-mode Pedestal Study Group of the International Tokamak Physics Activity presented by T.Osborne 19th IAEA Fusion Energy Conference

More information