1 1 EX/P4-2 Particle and Energy Transport in the SOL of DIII-D and NSTX J.A. Boedo 1), R.J. Maqueda 2), D.L. Rudakov 1), G.R. McKee 3), H. Kugel 4), R. Maingi 5), N. Crocker 6), R.A. Moyer 1), V.A. Soukhanovskii 7), J. Menard 4), J.G. Watkins 8), S.J. Zweben 4), D.A. D Ippolito 9), T.E. Evans 10), M.E. Fenstermacher 7), M. Groth 7), E.M. Hollmann 1), C.J. Lasnier 7), J.R. Myra 9), L.A. Roquemore 4), W.P. West 10), and L. Zeng 6) 1) University of California-San Diego, La Jolla, California, USA 2) Nova Photonics, Princeton, New Jersey, USA 3) University of Wisconsin-Madison, Madison, Wisconsin, USA 4) Princeton University, Princeton, New Jersey, USA 5) Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA 6) University of California-Los Angeles, Los Angeles, California, USA 7) Lawrence Livermore National Laboratory, Livermore, California, USA 8) Sandia National Laboratories, Albuquerque, New Mexico, USA 9) Lodestar Research Corp, Boulder, Colorado, USA 10) General Atomics, P.O. Box 85608, San Diego, California , USA contact of main author: Abstract. The far scrape-off layer (SOL) radial transport and plasma-wall contact is mediated by intermittent and ELM-driven transport. Experiments to characterize the intermittent transport and ELMs have been performed in both DIII-D and NSTX under similar conditions. Both intermittent transport and ELMs are comprised of filaments of hot, dense plasma ( n e ~1"10 13 cm #3, T e ~ 400 ev) originating at the edge, transport both particles and heat into the SOL by convection, increasing wall interaction and causing sputtering and impurity release. Both intermittent filaments and ELMs leave the pedestal region at speeds of ~0.5-3 km/s, losing heat and particles by parallel transport as they travel through the SOL. The intermittency shows many similarities in NSTX and DIII-D, featuring similar size (2-5!cm), large convective radial velocity, holes inside and peaks outside the LCFS which quickly decay and slow down with radius. Whereas in DIII-D the intermittency decays in both intensity and frequency in H-mode, it chiefly decays in frequency in NSTX. In the low collisionality ("* = # R q95 /$ C ) ("*~0.1, N G ~ 0.3) case, the ELMs impact the walls quite directly and account for ~90% of the wall particle flux, decreasing to ~30% at ("* ~ 1.0, N G > 0.6). INTRODUCTION Recent results show that the SOL density and temperature profiles in tokamaks and other devices are often non-exponential and flat, suggesting that perpendicular transport in these conditions is much larger than expected. Intermittent, radial ballistic transport, mediated by plasma filaments [1-3] is the vehicle for the enhanced radial transport and has been extensively documented in wide range of devices. Work on characterizing the transport, finding its origins and comparing with numerical simulations has been performed in linear devices [4,5], stellarators [6-9], (Weldenstein , Weldenstein VII-AS ), tokamaks [12,13], ALCATOR C-Mod [14-17], DIII-D [18-24], JT-60U [25,26], ASDEX , ASDEX- Upgrade [28-30], JET [31-34], CASTOR , and TCV ). Its statistical properties have been examined [37,38] via the probability distribution function (PDF) . The intermittent objects are born in the vicinity of LCFS at the low field side (LFS) of the torus, presumably as a result of interchange instability [40-43], and move towards the wall due to E " B drifts [1,3]. Modeling of the tokamak edge plasmas [44-46] incorporating this transport have shown that under certain conditions plasma contact with the main chamber wall may be significant! even when the distance to the wall is large compared with the density decay
2 2 EX/P4-2 length existing at the separatrix. Additionally, there is an extensive body of work imaging the edge of various devices with fast cameras [2,47,48] and beam emission spectroscopy (BES)  which show these objects as moving plasma filaments. ELMs, although of different origin as ballooning/peeling instabilities [50,51], have similar dynamics once in the SOL [34,52] and consist of a collection of bursts that travel radially at speeds of 1-3 km/s and rotate toroidally as they decay. The ELM plasma travels ballistically and strikes the wall with a flux dependant on collisionality/density [52,53], just as the intermittent filaments and an important question is what is the relative particle flux due to these two sources . Plasma interaction with the main chamber wall is of critical importance for next-step fusion devices such as ITER and it should be managed in order to prevent damage to the first wall elements and core plasma contamination with impurities. Comparative studies among devices are invaluable to gain insight on the basic physics of the origin of intermittency and the fundamental parameters driving the radial transport. Since inter-elm intermittent particle fluxes can exceed ELM-mediated fluxes, understanding the source of intermittent transport and its dependence on plasma parameters is critical for ITER. RESULTS Experiments to evaluate the intermittent transport and its variation with density/collisionality were performed in both NSTX ( I p 0.80 MA, B t =0.45 T, P in =1 MW, q 95 =7, W=0.2 MJ, V pl =11 m 3 ) and DIII-D ( I p =1 MA, B t = 2 T, P in = 1 MW, q 95 = 4.6, W=0.16!MJ, V pl =18.7!m 3 ) in both L-mode and H-mode discharges by scanning the line-averaged density. In DIII-D the density can be tightly controlled and the scan was performed in a shot-to-shot basis, as shown in Fig.!1, whereas in NSTX the density was allowed to ramp up naturally and data was taken at different times, as shown in Fig. 2(d). The density was FIG. 1. Time evolution of two otherwise identical DIII-D discharges with different densities. scanned over a wide range, in terms of the Greenwald fraction ( N G = n e " a 2 / I p ) from N G!~!0.12 to N G!~!0.5 in DIII-D and from N G!~!0.3 to N G!~ 0.8 in NSTX. The density scan is reflected by changes in the edge SOL profiles in both machines [Figs.!2(a-c) and 3]. These changes are concomitant with modifications in the microscopic behavior of the fluctuations as shown next. Pedestal/SOL measurements in DIII-D, shown in Fig. 4, indicate that: (1) the SOL widens and flattens as N G is increased as seen in the I sat profile [Fig. 4(a)], (2) the fluctuation rms level in I sat [Fig. 4(b)] increases with N G, (3) the E " rms levels [Fig. 4(c)] are mostly unaffected by the scan, and (4) changes are most noticeable at the highest N G in both devices (NSTX in Fig. 5). The E " rms signal can be interpreted as flux " = nv r, where V r rms = E " rms / Bt and therefore the transport increase in DIII-D is mostly due to increase in the density of the
3 3 EX/P4-2 FIG. 2. NSTX Thomson scattering edge/sol profiles of (a) temperature, (b) density, (c) electron pressure. The time evolution of the density and NBI power are shown in (d). FIG. 3. DIII-D Thomson scattering profiles for the discharges shown in Fig. 1 at 2500 ms and averaged over 200 ms. intermittent objects. In NSTX however, we observe that: (1) the SOL [Fig. 5(a)] flattens only at the highest densities, (2) the I sat rms levels [Fig.!5(b)] clearly increase with density in the edge/ LCFS but little in the SOL, (3) the I sat rms levels decrease with radius, indicating dissipation of the intermittent filaments, and (4) the E " rms levels [Fig.!5(c)] are mostly unaffected by the scan. Note that the E " rms levels are similar at the LCFS in both devices (~1200 V/m in DIII-D and ~!900!V/m in NSTX) but due to NSTX having a much lower Bt at the LCFS (~!1.8!T at DIII-D versus ~!0.25!T at NSTX, a factor of ~7), they correspond to much higher radial velocities at NSTX (~!1!km/s versus ~!3.5!km/s) for these low power L-mode conditions than in DIII-D. It is also noticeable that the rms velocity decreases rapidly with radius. Numerical simulations and other theoretical works [55-59] have proposed turbulence at the LCFS or thereabouts propagating into the SOL as the origin of the intermittency, in particular, the interchange instability  seems to reproduce the measured results well. An element of these models is the presence of density holes in the birth region of the intermittency; therefore, the data was tested by calculating the skewness of various signals and statistical analysis indicates that holes/peaks appear as negative/ positive skewness . The results are shown in Fig. 6(a,b) for NSTX and Fig. 6(c) for DIII-D. In the data we can observe: (1) the skewness of the I sat signal [Fig. 6(a)] is negative ( " ~ 1.2) inside the LCFS, crosses zero and becomes positive in the SOL; (2) there is a clear dependence of the skewness with density in the SOL (near SOL, not in the shadow of structures) that becomes apparent at the highest N G values ( ); (3)!similar, although less pronounced, behavior is observed in the E " rms [Fig. 6(b)] signal indicating inward radial velocity for some objects within the LCFS. The BES density signal in DIII-D [Fig. 6(c)] show similar behavior, suggesting the presence of a common mechanism in both devices.
4 4 EX/P4-2 FIG. 4. DIII-D reciprocating probe profiles of (a) I sat, (b) I sat rms and (c) E " rms. Dashed line indicates the EFIT separatrix. Imaging of the intermittent structures permits dynamics visualization and quantitative measurements of velocity, poloidal and radial extent, etc. In NSTX, the intermittency is imaged with high spatial and temporal resolution with the gas puff imaging (GPI) . It is clear that the intermittent objects are born from edge turbulence and that both broadband turbulence and intermittent objects are substantially reduced during H-mode with respect to the Ohmic or L-mode regimes. In Fig.!7(a-c) images from a ~23!x 23!cm radial versus poloidal portion of the edge just above the outer midplane are shown. Turbulence behavior varies widely from a turbulence level just above that measurable, a quiescent H-mode [Fig. 7(b)], to that approaching L-mode level shown in Fig.!7(c), at least for brief periods of time. The camera data allows the determination of poloidal and radial correlation lengths (4-9!cm and 2-6!cm respectively), poloidal velocities (up to 5!km/s in the ion diamagnetic drift direction) and radial velocities (up to 2!km/s outwards) [48,61]. The most significant change in the turbulence from L-mode to H-mode is a decrease in the fluctuations in the poloidal velocity of the turbulence, as if the flow was more frozen in H-mode. In DIII-D, the intermittent objects can be observed in 2D [Fig. 7(d)] with the BES system  which encompasses a smaller (5 x 6 cm) area, with lower resolution but better sensitivity than GPI. The intermittent objects look remarkably similar in both devices in size and dynamics. The measured intermittency radial velocity in the scrape-off layer appears to be bounded by a minimum velocity which can be explained theoretically  as imposed by a sheathconnected regime and a maximum velocity set by the resistive-ballooning regime. Intermittency changes character in H-mode; while in DIII-D the intensity and frequency of the filaments decrease as compared to L-mode, in NSTX only the frequency is reduced. INTERMITTTENT VS ELM-MEDIATED TRANSPORT NSTX and DIII-D showcase an abundance of ELM regimes  which allow comprehensive studies to be performed. Probe data taken in NSTX during Type I ELMs (Fig.!8), which consist of ~1-2 ms long sequence of ~5-30 fast bursts of hot, dense plasma, look identical to
5 5 EX/P4-2 FIG. 5. NSTX reciprocating probe profiles of (a) I sat, (b) I sat rms and (c) E " rms. Dashed line indicates the LRDFIT separatrix. data obtained from DIII-D . As the NSTX probe moves, a series of ELMinduced plasma filaments strike it and there- FIG. 6. NSTX reciprocating probe profiles of (a) skewness ( I sat ), (b) skewness of ( E " ) and (c) skewness of DIII-D BES data showing the transition from holes to bursts at the LCFS in both NSTX and DIII-D. Dashed line indicates the LRDFIT or EFIT separatrix. fore a plot of the peak saturation current (" n e T e ) versus radius can be assembled. A decay length of 1.7 cm for I sat, shown in Fig.!8(a), is determined by an exponential fit to the data; and the filament s velocity, calculated as V r = E " / B T, is of the order of 400!m/s at the LCFS [Fig.!8(b)] and features a decay length of ~7 cm; similar numbers as those in DIII-D . In
6 6 EX/P4-2 DIII-D it is found that whereas the energy is quickly reduced in the ELMs at all collisionalities, featuring a short (1-2!cm) decay length , the density decay length is highly dependent on collisionality. For low collisionality ( N G!~!0.5, "*~0.1), the ELM density decay length is long (~13!cm) indicating that the ELM particle flux impacts the walls quite directly whereas at high collisionality ( N G!~!0.8, "*~1), the particle flux decays in a short ~!3.5 cm. This change is concomitant with the transformation of ELMs into more grassy, lower amplitude types. FIG. 7. Imaging data (a-c) from the GPI system at NSTX showing intermittent behavior during Ohmic, quiescent H-mode and active H-mode respectively. Sequence of images obtained at 120,000!frames/s with each image exposed for 3!ms. A deuterium puff is injected from the right and D a light is imaged. Each image corresponds to ~23!x!23!cm (solid line: separatrix, dotted line: antenna limiter shadow). Two DIII-D BES frames, (d), taken 6 μs apart showing a coherent object leaving the separatrix (solid line) and moving radially and poloidally into the SOL. Frames cover a 5 x 6 cm area. FIG. 8. NSTX reciprocating probe data showing (a) decay of ELM amplitude ( I sat ) with radius and, (b) ELM radial velocity (V r = E " / Bt ) decaying slowly into the SOL. A weakening of the ELM-induced radial particle flux with collisionality (ELMs become grassier and smaller at high collisionality), coupled with a simultaneous strengthening of the intermittent transport demands a quantification of the relative importance of these two transport vehicles. Figure 9 compares various ELM and inter-elm SOL parameters (T e, n e, n e and q ) in L- and H-mode for similar collisionality ( N G!~!0.5, "* ~ 0.4 ) showing that Type I ELM density, temperature and fluctuations, can be momentarily comparable, and even higher, than L-mode ones in most conditions but is dependent on the ELM duty cycle (and discharge density). Most remarkably, recent DIII-D work using collisionality scans , shown in Fig. 10, revealed that the fraction of the ion particle flux to the wall due to ELMs to the total ion flux (defined as f ELM = " ELM I si dt / " I si dt ) account for ~!90% of the wall Total particle flux at low collisionality (expressed as the Greenwald fraction N G ) N G ~ 0.3, decreasing to ~30% at N G!~!1.0. The implications of the previous data are significant since for high N G ITER discharges: (1) the
7 7 EX/P4-2 wall- plasma flux increases to at least 50% of the total, and (2) the intermittent particle transport will dominate at the wall. This is both good news and bad news since the load on the divertor is significantly reduced but it requires mitigation techniques at the walls and diagnostics. FIG. 9. Radial profile of n e (a), T e (b), n e fluctuations (c) and parallel heat flux (d) for LSN, 1.1!MA, otherwise similar L- and H-mode discharges. FIG. 10. Ratio of the ELM-mediated ion flux to the total flux at the wall as function of N G. Work supported by the U.S. Department of Energy under DE-FC02-04ER54698, DE-FG02-04ER54758, DE-FG03-01ER54615, W ENG-48, DE-AC05-00OR22725, DE-FG02-89ER53296, DE-AC04-94AL85000, and DE- AC02-76CH REFERENCES  RENNER, H., et al., Plasma Phys. Control. Fusion 37 (1995) A53.  JHA, R., SAXENA, Y.C., Phys. Plasmas 3 (1996)  FILIPPAS, A.V., et al., Phys. Plasmas 2 (1995) 839.  KRASHENINNIKOV, S.I., Phys. Lett. A 283 (2001) 368.  ZWEBEN, S.J., Phys. Fluids 28 (1985) 974.  D IPPOLITO, D., et al., Phys. Plasmas 9 (2002) 222.  NIELSEN, A.H., et al., Phys. Plasmas 3 (1996)  LEHMER, R.D., Ph.D. thesis, Univ. California Los Angeles, UCSDENG-032, (1996).  SANCHEZ, E., et al., Phys. Plasmas 7 (2000)  LYON, J.F., et al., Fusion Technol. 10 (1986) 179.  GARCIA-CORTES, M.A. et al., Phys. Fluids B 4 (1992)  GARCIA-CORTES, I., et al., Plasma Phys. Control. Fusion 42 (2000) 389.  JOSEPH, B.K., et al., Phys. Plasmas 4 (1997) 4292.
8 8 EX/P4-2  UMANSKY, M.V., et al., Phys. Plasmas 5 (1998)  LaBOMBARD, B., et al., Phys. Plasmas 8 (2001)  TERRY, J.L., et al., Phys. Plasmas 10 (2003)  ZWEBEN, S.J., et al., Phys. Plasmas 9 (2002)  WATKINS, J.G., et al., J. Nucl. Mater (1992) 829.  WADE, M., et al., J. Nucl. Mater (1999) 44.  BOEDO, J.A., et al., Phys. Plasmas 8 (2001)  RUDAKOV, D.L., et al., Plasma Phys. Control. Fusion 44 (2002) 717.  BOEDO, J.A., et al., J. Nucl. Mater (2003) 813.  BOEDO, J.A., et al., Phys. Plasmas 10 (2003)  FENSTERMACHER, M.E., et al., Plasma Phys. Control. Fusion 45 (2003)  ASAKURA, N., et al., J. Nucl. Mater (1997) 559.  ASAKURA, N., et al., J. Nucl. Mater (2005) 712.  ENDLER, M., et al., Nucl. Fusion 35 (1995)  NEUHAUSER, J., et al., Plasma Phys. Control. Fusion 44 (2002) 855.  KALLENBACH, A., et al., Nucl. Fusion 43 (2003) 573.  HERRMANN, A., et al., Plasma Phys. Control. Fusion 46 (2004) 971.  GHENDRIH, Ph., et al., J. Nucl. Mater (2003) 914.  GONCALVES, B., et al., Plasma Phys. Control. Fusion 45 (2003).  FUNDAMENSKI, W., et al., Plasma Phys. Control. Fusion 46 (2004) 233.  ENDLER, M., et al., Plasma Phys. Control. Fusion 47 (2005)  SOTECKEL, J., et al., Phys. Plasmas 6 (1999) 846.  HORACEK, J., J. Physics (Czechoslovak) 55(3) (2005)  CARRERAS, B., et al., Phys. Plasmas 7 (2000)  CARRERAS, B.A., Phys. Plasmas 8 (2001)  SANCHEZ, E., et al., Phys. Plasmas 7 (2000)  ENDLER, M., et al., Nucl. Fusion 35 (1995)  NEDOSPASOV, A.V., Sov. J. Plasma Phys. 15 (1989) 659.  GARBET, X., et al., Nucl. Fusion 31 (1991) 967.  SARAZIN, Y., Phys. Plasmas 5 (1998)  UMANSKY, M.V., et al., Phys. Plasmas 5 (1998)  PIGAROV, A.Yu., et al., Phys. Plasmas 9 (2002)  PIGAROV, A.Yu., et al., J. Nucl. Mater (2003)  MAQUEDA, R.J., et al., Rev. Sci. Instrum. 74 (2003)  ZWEBEN, S.J., et al., Nucl. Fusion 44 (2004) 134.  McKEE, G.R., et al., Rev. Sci. Instrum. 70 (1999) 913.  CONNOR, J.W., et al., Phys. Plasmas 5 (2002)  SNYDER, P.B., et al., Phys. Plasmas 9 (2002)  Boedo, J.A., Phys. Plasmas 12 (2005)  LEONARD, A.W., et al., to be published in J. Nucl. Mat. (2006).  RUDAKOV, D.L., et al., Nucl. Fusion 45 (2005)  BIAN, N., et al., Phys. Plasmas 10(3) (2003)  SARAZIN, Y., et al., J. Nucl. Mat (2003)  XU, X.Q., Phys. Plasmas 10 (2003)  RUSSELL, D., et al., Phys. Rev. Lett. 93 (2004)  MYRA, J., et al., Phys. Plasmas 12 (2005)  MAQUEDA, R.J., et al., Rev. Sci. Instrum. 74 (2003)  ZWEBEN, S.J., et al., Phys. Plasmas 13, (2006).  MYRA, J.R., et al., this conference.  MAINGI, R., et al. Nucl. Fusion 45 (2005) 1066.
GA A24724 FAR SCRAPE-OFF LAYER AND NEAR WALL PLASMA STUDIES IN DIII D by D.L. RUDAKOV, J.A. BOEDO, R.A. MOYER, N.H. BROOKS, R.P. DOERNER, T.E. EVANS, M.E. FENSTERMACHER, M. GROTH, E.M. HOLLMANN, S. KRASHENINNIKOV,
1 Scaling of divertor heat flux profile widths in DIII-D C.J. Lasnier 1, M.A. Makowski 1, J.A. Boedo 2, N.H. Brooks 3, D.N. Hill 1, A.W. Leonard 3, and J.G. Watkins 4 e-mail:email@example.com 1 Lawrence
P1-59 Blob sizes and velocities in the Alcator C-Mod scrapeoff layer R. Kube a,b,*, O. E. Garcia a,b, B. LaBombard b, J. L. Terry b, S. J. Zweben c a Department of Physics and Technology, University of
LLNL-PROC-432803 Scaling of divertor heat flux profile widths in DIII-D C. J. Lasnier, M. A Makowski, J. A. Boedo, S. L. Allen, N. H. Brooks, D. N. Hill, A. W. Leonard, J. G. Watkins, W. P. West May 20,
GA A26119 MEASUREMENTS AND SIMULATIONS OF SCRAPE-OFF LAYER FLOWS IN THE DIII-D TOKAMAK by M. GROTH, G.D. PORTER, J.A. BOEDO, N.H. BROOKS, R.C. ISLER, W.P. WEST, B.D. BRAY, M.E. FENSTERMACHER, R.J. GROEBNER,
Connections between Particle Transport and Turbulence Structures in the Edge and SOL of Alcator C-Mod I. Cziegler J.L. Terry, B. LaBombard, J.W. Hughes MIT - Plasma Science and Fusion Center th 19 Plasma
Alcator C-Mod Particle Transport in the Scrape-off Layer and Relationship to Discharge Density Limit in Alcator C-Mod B. LaBombard, R.L. Boivin, M. Greenwald, J. Hughes, B. Lipschultz, D. Mossessian, C.S.
GA A25445 TARGET PLATE CONDITIONS DURING STOCHASTIC BOUNDARY OPERATION ON DIII D by J.G. WATKINS, T.E. EVANS, C.J. LASNIER, R.A. MOYER, and D.L. RUDAKOV JUNE 2006 QTYUIOP DISCLAIMER This report was prepared
Alcator C-Mod Particle Transport in the Alcator C-Mod Scrape-off Layer B. LaBombard, R.L. Boivin, B. Carreras, M. Greenwald, J. Hughes, B. Lipschultz, D. Mossessian, C.S. Pitcher, J.L. Terry, S.J. Zweben,
ArbiTER studies of filamentary structures in the SOL of spherical tokamaks D. A. Baver, J. R. Myra, Research Corporation F. Scotti, Lawrence Livermore National Laboratory S. J. Zweben, Princeton Plasma
GA A26123 PARTICLE, HEAT, AND SHEATH POWER TRANSMISSION FACTOR PROFILES DURING ELM SUPPRESSION EXPERIMENTS ON DIII-D by J.G. WATKINS, T.E. EVANS, I. JOSEPH, C.J. LASNIER, R.A. MOYER, D.L. RUDAKOV, O. SCHMITZ,
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
20 th IAEA Fusion Energy Conference Vilamoura, Portugal, 1 to 6 November 2004 IAEA-CN-116/EX/P5-19 IMPLICATIONS OF WALL RECYCLING AND CARBON SOURCE LOCATIONS ON CORE PLASMA FUELING AND IMPURITY CONTENT
Plasma Phys. Control. Fusion 41 (1999) A345 A355. Printed in the UK PII: S741-3335(99)97299-8 Physics of the detached radiative divertor regime in DIII-D M E Fenstermacher, J Boedo, R C Isler, A W Leonard,
1 Dependences of the ertor and plane heat flux widths in NSTX T.K. Gray1,2), R. Maingi 2), A.G. McLean 2), V.A. Soukhanovskii 3) and J-W. Ahn 2) 1) Oak Ridge Institute for Science and Education (ORISE),
Journal of Nuclear Materials 266±269 (1999) 1145±1150 Potentials, E B drifts, and uctuations in the DIII-D boundary R.A. Moyer a, *, R. Lehmer a, J.A. Boedo a, J.G. Watkins b,x.xu c, J.R. Myra d, R. Cohen
1 EX/P4-28 Divertor Heat Flux Reduction and Detachment in NSTX V. A. Soukhanovskii 1), R. Maingi 2), R. Raman 3), R. E. Bell 4), C. Bush 2), R. Kaita 4), H. W. Kugel 4), C. J. Lasnier 1), B. P. LeBlanc
EX/D- Density Limit and Cross-Field Edge Transport Scaling in Alcator C-Mod B. LaBombard ), M. Greenwald ), R.L. Boivin ), B..A. Carreras 3), J.W. Hughes ), B. Lipschultz ), D. Mossessian ), C.S. Pitcher
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,
GA A25451 MIGRATION OF ARTIFICIALLY INTRODUCED MICRON-SIZE CARBON DUST IN THE DIII D DIVERTOR by D.L. RUDAKOV, W.P. WEST, C.P.C. WONG, N.H. BROOKS, T.E. EVANS, M.E. FENSTERMACHER, M. GROTH, S.I. KRASHENINNIKOV,
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
GA A27437 SCALING OF THE DIVERTOR HEAT FLUX WIDTH IN THE DIII-D TOKAMAK by M.A. MAKOWSKI, A.W. LEONARD, J.D. ELDER, C.J. LASNIER, J. NICHOLS, T.H. OSBORNE, P.C. STANGEBY and J.G. WATKINS OCTOBER 2012 DISCLAIMER
Edge Zonal Flows and Blob Propagation in Alcator C-Mod S.J. Zweben 1, J.L. Terry 2, M. Agostini 3, B. Davis 1, O. Grulke 4,J. Hughes 2, B. LaBombard 2 D.A. D'Ippolito 6, R. Hager 5, J.R. Myra 6, D.A. Russell
Constraining the divertor heat width in ITER D.G. Whyte 1, B. LaBombard 1, J.W. Hughes 1, B. Lipschultz 1, J. Terry 1, D. Brunner 1, P.C. Stangeby 2, D. Elder 2, A.W. Leonard 3, J. Watkins 4 1 MIT Plasma
EX/D-3 Driving Mechanism of SOL Plasma Flow and Effects on the Divertor Performance in JT-6U N. Asakura ), H. Takenaga ), S. Sakurai ), G.D. Porter ), T.D. Rognlien ), M.E. Rensink ), O. Naito ), K. Shimizu
GA A23411 COMPARISON OF LANGMUIR PROBE AND THOMSON SCATTERING by J.G. WATKINS, P.C. STANGEBY, J.A. BOEDO, T.N. CARLSTROM, C.J. LASNIER, R.A. MOYER, D.L. RUDAKOV, D.G. WHYTE JULY 2000 DISCLAIMER This report
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,
Plasma Science and Fusion Center Turbulence and transport studies in ALCATOR C Mod using Phase Contrast Imaging (PCI) Diagnos@cs and Comparison with TRANSP and Nonlinear Global GYRO Miklos Porkolab (in
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.
Convective transport by intermittent blob-filaments: comparison of theory and experiment D. A. D Ippolito 1, J. R. Myra 1 and S. J. Zweben 2 1Lodestar Research Corporation, Boulder, Colorado 2Princeton
EFFECT OF EDGE NEUTRAL SOUCE PROFILE ON H-MODE PEDESTAL HEIGHT AND ELM SIZE T.H. Osborne 1, P.B. Snyder 1, R.J. Groebner 1, A.W. Leonard 1, M.E. Fenstermacher 2, and the DIII-D Group 47 th Annual Meeting
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.
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,
PFC/JA-95-28 Edge Turbulence Measurements during the L- to H-Mode Transition by Phase Contrast Imaging on DIII-Dt Coda, S.; Porkolab, M.; Plasma Fusion Center Massachusetts Institute of Technology Cambridge,
1 9/2/16 L-mode filament characteristics on MAST as a function of plasma current measured using visible imaging A. Kirk, A.J. Thornton, J.R. Harrison, F. Militello, N.R. Walkden and the MAST Team and the
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
GA A26116 THE CONCEPTUAL MODEL OF THE MAGNETIC TOPOLOGY AND NONLINEAR DYNAMICS OF ELMs by T.E. EVANS, J.H. YU, M. JAKUBOWSKI, O. SCHMITZ, J.G. WATKINS, and R.A. MOYER JUNE 2008 DISCLAIMER This report was
Development of an experimental profile database for the scrape-off layer M. Groth, 1 G.D. Porter, 1 W.M. Meyer, 1 A.W. Leonard, 2 T.H. Osborne, 2 D.P. Coster, 3 A. Kallenbach, 3 M. Wischmeier 3 N.H. Brooks,
GA A27235 EULERIAN SIMULATIONS OF NEOCLASSICAL FLOWS AND TRANSPORT IN THE TOKAMAK PLASMA EDGE AND OUTER CORE by E.A. BELLI, J.A. BOEDO, J. CANDY, R.H. COHEN, P. COLELLA, M.A. DORF, M.R. DORR, J.A. HITTINGER,
Penetration of filamentary structures into the divertor region of spherical tokamaks D. A. Baver and J. R. Myra Lodestar Research Corporation, 2400 Central Avenue P-5, Boulder, CO 80301, USA October 2018
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),
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
Flow measurements in the Scrape-Off Layer of Alcator C-Mod using Impurity Plumes S. Gangadhara,. Laombard M.I.T. Plasma Science and Fusion Center, 175 Albany St., Cambridge, MA 2139 USA Abstract Accurate
Drift-Driven and Transport-Driven Plasma Flow Components in the Alcator C-Mod Boundary Layer N. Smick, B. LaBombard MIT Plasma Science and Fusion Center PSI-19 San Diego, CA May 25, 2010 Boundary flows
IOP PUBLISHING and INTERNATIONAL ATOMIC ENERGY AGENCY Nucl. Fusion 7 (7) 667 676 NUCLEAR FUSION doi:.88/9-1/7/7/17 Fluctuations and transport in the TCV scrape-off layer O.E. Garcia 1, J. Horacek, R.A.
Journal of Nuclear Materials 266±269 (1999) 380±385 Enhanced con nement discharges in DIII-D with neon and argon induced radiation G.L. Jackson a, *, M. Murakami b, G.M. Staebler a, M.R. Wade b, A.M. Messiaen
GA A26565 LIMITS TO H-MODE PEDESTAL PRESSURE GRADIENT IN DIII-D by R.J. GROEBNER, P.B. SNYDER, T.H. OSBORNE, A.W. LEONARD, T.L. RHODES, L. ZENG, E.A. UNTERBERG, Z. YAN, G.R. McKEE, C.J. LASNIER, J.A. BOEDO,
PHYSICS OF PLASMAS VOLUME 7, NUMBER 11 NOVEMBER 2000 Helium-3 transport experiments in the scrape-off layer with the Alcator C-Mod omegatron ion mass spectrometer R. Nachtrieb a) Lutron Electronics Co.,
Evidence for Electromagnetic Fluid Drift Turbulence Controlling the Edge Plasma State in B. LaBombard, J.W. Hughes, D. Mossessian, M. Greenwald, J.L. Terry, Team Contributed talk CO.00 Presented at the
High Speed Imaging of Edge Turbulence in NSTX S.J. Zweben, R. Maqueda 1, D.P. Stotler, A. Keesee 2, J. Boedo 3, C. Bush 4, S. Kaye, B. LeBlanc, J. Lowrance 5, V. Mastrocola 5, R. Maingi 4, N. Nishino 6,
Effect of divertor nitrogen seeding on the power exhaust channel width in Alcator C-Mod B. LaBombard, D. Brunner, A.Q. Kuang, W. McCarthy, J.L. Terry and the Alcator Team Presented at the International
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,
UCRL-JC-129497 Preprint Simulation of Plasma Flow in the DIII-D Tokamak G.D Porter, T D. Rognlien, N. Wolf, J Boedo, R.C Isler This paper was prepared for submittal to 1998 International Congress on Plasma
Results From Initial Snowflake Divertor Physics Studies on DIII-D S. L. Allen, V. A. Soukhanovskii, T.H. Osborne, E. Kolemen, J. Boedo, N. Brooks, M. Fenstermacher, R. Groebner, D. N. Hill, A. Hyatt, C.
Operational Phase Space of the Edge Plasma in B. LaBombard, T. Biewer, M. Greenwald, J.W. Hughes B. Lipschultz, N. Smick, J.L. Terry, Team Contributed talk RO.00008 Presented at the 47th Annual Meeting
Edge Rotational Shear Requirements for the Edge Harmonic Oscillation in DIII D Quiescent H mode Plasmas by T.M. Wilks 1 with A. Garofalo 2, K.H. Burrell 2, Xi. Chen 2, P.H. Diamond 3, Z.B. Guo 3, X. Xu
GA A27418 THE ROLE OF ZONAL FLOWS AND PREDATOR- PREY OSCILLATIONS IN THE FORMATION OF CORE AND EDGE TRANSPORT BARRIERS by L. SCHMITZ, L. ZENG, T.L. RHODES, J.C. HILLESHEIM, W.A. PEEBLES, R.J. GROEBNER,
University of California, San Diego UCSD-CER-06-07 DIII-D Edge Physics and Disruptions FY04-06 Progress Report J. A. Boedo, C. Holland, E. Hollmann, R. Moyer, D. Rudakov and G. R. Tynan June 2006 Center
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
J Plasma Fusion Res SERIES, Vol 6 (004) 6 (004) 139 143 000 000 Large Plasma Pressure Perturbations and Radial Convective Transport in a Tokamak KRASHENINNIKOV Sergei, RYUTOV Dmitri 1 and YU Guanghui University
H-mode Pedestal Enhancement and Improved Confinement in DIII-D with Lithium Injection by G.L. Jackson, with R. Maingi, T.H. Osborne, D.K. Mansfield, C.P. Chrobak, B.A. Grierson, A.G. McLean, Z. Yan, S.L.
D.J. Schlossberg, D.J. Battaglia, M.W. Bongard, R.J. Fonck, A.J. Redd University of Wisconsin - Madison 1500 Engineering Drive Madison, WI 53706 Concept Overview Implementation on PEGASUS Results Current
Fluctuation statistics in the scrape-off layer of Alcator C-Mod R. Kube, O. E. Garcia, B. LaBombard, and J. L. Terry We study long time series of the ion saturation current and floating potential, obtained
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,
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
GA A2342 ONION-SKIN METHOD (OSM) ANALYSIS OF DIII D EDGE MEASUREMENTS by P.C. STANGEBY, J.G. WATKINS, G.D. PORTER, J.D. ELDER, S. LISGO, D. REITER, W.P. WEST, and D.G. WHYTE JULY 2 DISCLAIMER This report
Initial Investigations of H-mode Edge Dynamics in the PEGASUS Toroidal Experiment M.W. Bongard, R.J. Fonck, K.E. Thome, D.S. Thompson 55 th Annual Meeting of the APS Division of Plasma Physics University
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)
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,
th IAEA Fusion Energy Conference Vilamoura, Portugal, to 6 November IAEA-CN-6/EX/P-7 STATIONARY, HIGH BOOTSTRAP FRACTION PLASMAS IN DIII-D WITHOUT INDUCTIVE CURRENT CONTROL P.A. POLITZER, A.W. HYATT, T.C.
Broadband Magnetic and Density Fluctuation Evolution Prior to First ELM in DIII-D Edge Pedestal Presented by G. Wang a, In collaboration with W.A. Peebles a, P.B. Snyder b, T.L. Rhodes a, E.J. Doyle a,
Flow Measurements in the DIII-D Divertor Flow Measurements in the Divertor Region of DIII-D and Plasma Characterization using a Reciprocating Probe J. Boedo, R. Lehmer, R. Moyer, J. Watkins, D. Hill, T.
Edge Impurity Dynamics During an ELM Cycle in by M.R. Wade 1 in collaboration with K.H. Burrell, A.W. Leonard, T.H. Osborne, P.B. Snyder, J.T. Hogan, 1 and D. Coster 3 1 Oak Ridge National Laboratory General
UCRL-JC-130766 Preprint Detached Divertor Operation in DIII-D Helium Plasmas D.N. Hill, M.E. Fenstermacher, C.J. Lasnier, A.W. Leonard, M.R. Wade, W.P. West, and R.D. Wood This paper was prepared for submittal
GA A22993 EFFECTS OF PLASMA SHAPE AND PROFILES ON EDGE by L.L. LAO, V.S. CHAN, L. CHEN, E.J. DOYLE, J.R. FERRON, R.J. GROEBNER, G.L. JACKSON, R.J. LA HAYE, E.A. LAZARUS, G.R. McKEE, R.L. MILLER, M. MURAKAMI,
Varia%ons in Edge and SOL Turbulence in NSTX S.J. Zweben 1*, W.M. Davis 1, S.M. Kaye 1, J.R. Myra 2, R.E. Bell 1, B.P LeBlanc 1, R.J. Maqueda 1**, T. Munsat 3, S.A. Sabbagh 4, Y. Sechrest 3, D.P. Stotler
1 Reduced Electron Thermal Transport in Low Collisionality H-mode Plasmas in DIII-D and the Importance of Small-scale Turbulence L. Schmitz, 1 C. Holland, 2 T.L. Rhodes, 1 G. Wang, 1 L. Zeng, 1 A.E. White,
GA A24699 SUPPRESSION OF LARGE EDGE LOCALIZED MODES IN HIGH CONFINEMENT DIII D PLASMAS WITH A STOCHASTIC MAGNETIC BOUNDARY by T.E. EVANS, R.A. MOYER, J.G. WATKINS, P.R. THOMAS, J.A. BOEDO, M.E. FENSTERMACHER,
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
PSFC/JA-05-4 Evidence for electromagnetic fluid drift turbulence controlling the edge plasma state in the Alcator C-Mod tokamak B. LaBombard, J.W. Hughes, D. Mossessian, M. Greenwald, B. Lipschultz, J.L.
GA A27805 EXPANDING THE PHYSICS BASIS OF THE BASELINE Q=10 SCENRAIO TOWARD ITER CONDITIONS by T.C. LUCE, G.L. JACKSON, T.W. PETRIE, R.I. PINSKER, W.M. SOLOMON, F. TURCO, N. COMMAUX, J.R. FERRON, A.M. GAROFALO,
D.J. Schlossberg, D.J. Battaglia, M.W. Bongard, R.J. Fonck, A.J. Redd University of Wisconsin - Madison 1500 Engineering Drive Madison, WI 53706 Non-solenoidal startup using point-source DC helicity injectors
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,