TY - JOUR
T1 - Filamentary velocity scaling validation in the TCV tokamak
JF - Physics of Plasmas
Y1 - 2018
A1 - Tsui, C. K.
A1 - Boedo, J. A.
A1 - Myra, J. R.
A1 - Duval, B.
A1 - Labit, B.
A1 - Theiler, C.
A1 - Vianello, N.
A1 - Vijvers, W. A. J.
A1 - Reimerdes, H.
A1 - Coda, S.
A1 - Février, O.
A1 - Harrison, J. R.
A1 - Horacek, J.
A1 - Lipschultz, B.
A1 - Maurizio, R.
A1 - Nespoli, F.
A1 - Sheikh, U.
A1 - Verhaegh, K.
A1 - Walkden, N.
A1 - TCV team
A1 - EUROfusion MST1 Team
AB - A large database of reciprocating probe data from the edge plasma of TCV (Tokamak à Configuration Variable) is used to test the radial velocity scalings of filaments from analytical theory [Myra et al., Phys. Plasmas 13, 112502 (2006)]. The measured velocities are mainly scattered between zero and a maximum velocity which varies as a function of size and collisionality in agreement with the analytical scalings. The scatter is consistent with mechanisms that tend to slow the velocity of individual filaments. While the radial velocities were mainly clustered between 0.5 and 2 km/s, a minority reached outward velocities as high as 5 km/s or inward velocities as high as −4 km/s. Inward moving filaments are only observed in regions of high poloidal velocity shear in discharges with B × ∇B away from the X-point, a new finding. The filaments have diameters clustered between 3 and 11 mm, and normalized sizes aˆ clustered between 0.3 and 1.1, such that most filaments populate the resistive-ballooning regime; therefore, most of the filaments in TCV have radial velocities with little or no dependence on collisionality. Improvements in cross-correlation techniques and conditional averaging techniques are discussed which reduce the sizes determined for the largest filaments, including those larger than the scrape-off layer.
VL - 25
IS - 7
U1 - FP
U2 - PEPD
U5 - 704d56f331c2957ba040347833d95417
ER -
TY - JOUR
T1 - Physics conclusions in support of ITER W divertor monoblock shaping
JF - Nuclear Materials and Energy
Y1 - 2017
A1 - Pitts, R. A.
A1 - Bardin, S.
A1 - Bazylev, B.
A1 - van den Berg, M. A.
A1 - Bunting, P.
A1 - Carpentier, S.
A1 - Coenen, J. W.
A1 - Corre, Y.
A1 - Dejarnac, R.
A1 - Escourbiac, F.
A1 - Gaspar, J.
A1 - Gunn, J. P.
A1 - Hirai, T.
A1 - Hong, S. H.
A1 - Horacek, J.
A1 - Iglesias, D.
A1 - Komm, M.
A1 - Krieger, K.
A1 - Lasnier, C.
A1 - Matthews, G. F.
A1 - Morgan, T. W.
A1 - Panayotis, S.
A1 - Pestchanyi, S.
A1 - Podolnik, A.
A1 - Nygren, R. E.
A1 - Rudakov, D. L.
A1 - De Temmerman, G.
A1 - Vondracek, P.
A1 - Watkins, J. G.
AB - The key remaining physics design issue for the ITER tungsten (W) divertor is the question of monoblock (MB) front surface shaping in the high heat flux target areas of the actively cooled targets. Engineering tolerance specifications impose a challenging maximum radial step between toroidally adjacent MBs of 0.3 mm. Assuming optical projection of the parallel heat loads, magnetic shadowing of these edges is required if quasi-steady state melting is to be avoided under certain conditions during burning plasma operation and transiently during edge localized mode (ELM) or disruption induced power loading. An experiment on JET in 2013 designed to investigate the consequences of transient W edge melting on ITER, found significant deficits in the edge power loads expected on the basis of simple geometric arguments, throwing doubt on the understanding of edge loading at glancing field line angles. As a result, a coordinated multi-experiment and simulation effort was initiated via the International Tokamak Physics Activity (ITPA) and through ITER contracts, aimed at improving the physics basis supporting a MB shaping decision from the point of view both of edge power loading and melt dynamics. This paper reports on the outcome of this activity, concluding first that the geometrical approximation for leading edge power loading on radially misaligned poloidal leading edges is indeed valid. On this basis, the behaviour of shaped and unshaped monoblock surfaces under stationary and transient loads, with and without melting, is compared in order to examine the consequences of melting, or power overload in context of the benefit, or not, of shaping. The paper concludes that \{MB\} top surface shaping is recommended to shadow poloidal gap edges in the high heat flux areas of the ITER divertor targets.
VL - 12
U1 - PSI
U2 - PMI
U5 - 2db671decc9445e50dc9f54825572e3b
ER -
TY - JOUR
T1 - Overview of MAST results
JF - Nuclear Fusion
Y1 - 2015
A1 - Chapman, I.T.
A1 - Adamek, J.
A1 - Akers, R. J.
A1 - Allan, S.
A1 - Appel, L.
A1 - Asunta, O.
A1 - Barnes, M.
A1 - N. Ben Ayed
A1 - Hawke, J.
A1 - Bigelow, T.
A1 - Boeglin, W.
A1 - Bradley, J.
A1 - Brünner, J.
A1 - Cahyna, P.
A1 - Carr, M.
A1 - Caughman, J.
A1 - Cecconello, M.
A1 - Challis, C.
A1 - Chapman, S.
A1 - Chorley, J.
A1 - Colyer, G.
A1 - Conway, N.
A1 - Cooper, W. A.
A1 - Cox, M.
A1 - Crocker, N.
A1 - Crowley, B.
A1 - Cunningham, G.
A1 - Danilov, A.
A1 - Darrow, D.
A1 - Dendy, R.
A1 - Diallo, A.
A1 - Dickinson, D.
A1 - Diem, S.
A1 - Dorland, W.
A1 - Dudson, B.
A1 - Dunai, D.
A1 - Easy, L.
A1 - Elmore, S.
A1 - Field, A.
A1 - Fishpool, G.
A1 - Fox, M.
A1 - Fredrickson, E.
A1 - Freethy, S.
A1 - Garzotti, L.
A1 - Ghim, Y. C.
A1 - Gibson, K.
A1 - Graves, J.
A1 - Gurl, C.
A1 - Guttenfelder, W.
A1 - Ham, C.
A1 - Harrison, J.
A1 - Harting, D.
A1 - Havlickova, E.
A1 - Hawkes, N.
A1 - Hender, T.
A1 - Henderson, S.
A1 - Highcock, E.
A1 - Hillesheim, J.
A1 - Hnat, B.
A1 - Holgate, J.
A1 - Horacek, J.
A1 - Howard, J.
A1 - Huang, B.
A1 - Imada, K.
A1 - Jones, O.
A1 - S. Kaye
A1 - Keeling, D.
A1 - Kirk, A.
A1 - Klimek, I.
A1 - Kocan, M.
A1 - Leggate, H.
A1 - Lilley, M.
A1 - Lipschultz, B.
A1 - Lisgo, S.
A1 - Liu, Y. Q.
A1 - Lloyd, B.
A1 - Lomanowski, B.
A1 - Lupelli, I.
A1 - Maddison, G.
A1 - J. Mailloux
A1 - Martin, R.
A1 - McArdle, G.
A1 - McClements, K.
A1 - McMillan, B.
A1 - Meakins, A.
A1 - Meyer, H.
A1 - Michael, C.
A1 - Militello, F.
A1 - Milnes, J.
A1 - Morris, A. W.
A1 - Motojima, G.
A1 - Muir, D.
A1 - Nardon, E.
A1 - Naulin, V.
A1 - Naylor, G.
A1 - Nielsen, A.
A1 - O'Brien, M.
A1 - O'Gorman, T.
A1 - Ono, Y.
A1 - Oliver, H.
A1 - Pamela, S.
A1 - Pangioni, L.
A1 - Parra, F.
A1 - Patel, A.
A1 - Peebles, W.
A1 - Peng, M.
A1 - Perez, R.
A1 - Pinches, S.
A1 - Piron, L.
A1 - Podesta, M.
A1 - Price, M.
A1 - Reinke, M.
A1 - Ren, Y.
A1 - Roach, C.
A1 - Robinson, J.
A1 - Romanelli, M.
A1 - Rozhansky, V.
A1 - Saarelma, S.
A1 - Sangaroon, S.
A1 - Saveliev, A.
A1 - Scannell, R.
A1 - Schekochihin, A.
A1 - Sharapov, S.
A1 - Sharples, R.
A1 - Shevchenko, V.
A1 - Silburn, S.
A1 - J. Simpson
A1 - Storrs, J.
A1 - Takase, Y.
A1 - Tanabe, H.
A1 - Tanaka, H.
A1 - Taylor, D.
A1 - Taylor, G.
A1 - Thomas, D.
A1 - Thomas-Davies, N.
A1 - Thornton, A.
A1 - Turnyanskiy, M.
A1 - Valovic, M.
A1 - Vann, R.
A1 - Walkden, N.
A1 - Wilson, H.
A1 - Wyk, L. V.
A1 - Yamada, T.
A1 - Zoletnik, S.
A1 - MAST Team
A1 - MAST Upgrade Teams
VL - 55
IS - 10
U1 - FP
U2 - TP
U5 - 9d7b191e90422e8ed8bcf2078b75987f
ER -