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3. Effects of drifts on scrape-off layer transport in W7-X

Author

Kriete, D. M., Pandey, A., Perseo, V., Schmitt, J. C., Ennis, D. A., Gradic, D., Hammond, K. C., Jakubowski, M., Killer, C., König, R., Maurer, D. A., Reimold, F., Winters, V., Beurskens, M. N. A., Bozhenkov, S. A., Brunner, K. J., Fuchert, G., Knauer, J., Pasch, E., Scott, E. R., Gantenbein, Gerd, Illy, Stefan, Jelonnek, John, Krier, Laurent, Thumm, Manfred, Team, the W-X., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Nuclear and High Energy Physics, Technology, Condensed Matter Physics, ddc:600
Abstract

Drifts affect particle, momentum, and energy transport in the scrape-off layer (SOL) of tokamaks and stellarators, altering plasma flows and creating asymmetries between divertors. To understand how drifts affect SOL transport in the W7-X island divertor, an experiment was performed to compare plasmas with matched core parameters but opposite magnetic field directions, and therefore opposite drift transport directions. Parallel flow measurements made with coherence imaging spectroscopy are interpreted with the aid of a diagnostic forward model and a 1D simple SOL model that includes the E × B drift. In low-density plasmas ( n ‾ e < 2 × 10 19 m−3), the poloidal E × B drift induces a large poloidal density asymmetry within the island SOL, as measured by divertor Langmuir probes. This in turn causes the parallel flow stagnation point to shift from the position halfway between targets to the X-point in the drift direction, leading to near-unidirectional flow throughout the SOL. As density increases, the effects of the poloidal E × B drift decrease substantially, resulting in a smaller density asymmetry and the development of a counter-streaming flow pattern. For the entire density range probed in this experiment ( n ‾ e = 1.5 − 6 × 10 19 m−3), the experimental observations are more consistent with the effects of the poloidal E × B drift than the radial E × B drift.

Published
2023

4. Plasma���surface interaction in the stellarator W7-X: conclusions drawn from operation with graphite plasma-facing components

Author

W7-X Team, BrezƖnsek, S., Dhard, C. P., Jakubowski, M., König, R., Masuzaki, S., Mayer, M., Naujoks, D., Romazanov, J., Schmid, K., Schmitz, O., Zhao, D., Balden, M., Brakel, R., Butterschoen, B., Dittmar, T., Drews, P., Effenberg, F., Elgeti, S., Ford, O., Fortuna-Zalesna, E., Fuchert, G., Gao, Y., Goriaev, A., Hakola, A., Kremeyer, T., Krychowiak, M., Liang, Y., Linsmeier, Ch., Lunsford, R., Motojima, G., Neu, R., Neubauer, O., Oelmann, J., Petersson, P., Rasinski, M., Rubel, M., Sereda, S., Sergienko, G., Sunn Pedersen, T., Vuoriheimo, T., Wang, E., Wauters, T., Winters, V., Zhao, M., Yi, R., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Thumm, Manfred, Wadle, Simone, and Weggen, Jörg

Subjects
Technology, ddc:600
Published
2022
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5. Analysis of hydrogen fueling, recycling, and confinement at Wendelstein 7-X via a single-reservoir particle balance

Author

Kremeyer, Thierry, König, R., Brezinsek, S., Schmitz, O., Feng, Y., Winters, V., Rudischhauser, L., Buttenschön, B., Brunner, K. J., Drewelow, P., Flom, E., Fuchert, G., Gao, Y., Geiger, J., Jakubowski, M., Killer, C., Knauer, J., Krychowiak, M., Lazerson, S., Reimold, F., Schlisio, G., Viebke, H., the W7-X Team, Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Thumm, Manfred, Wadle, Simone, and Weggen, Jörg

Subjects
Technology, ddc:600
Published
2022
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6. Gas exhaust in the Wendelstein 7-X stellarator during the first divertor operation

Author

Wenzel, U., Schlisio, G., Drewelow, P., Krychowiak, M., König, R., Pedersen, T. S., Bozhenkov, S., Haak, V., Kharwandikar, A. K., Lazerson, S., Naujoks, D., Perseo, V., Winters, V., Team, The W7-X, Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Technology, Nuclear and High Energy Physics, Condensed Matter Physics, ddc:600
Abstract

The optimized superconducting stellarator Wendelstein 7-X (W7-X) is equipped with an island divertor for energy control and efficient pumping. We investigated the performance of the island divertor in terms of gas exhaust. For this purpose we have installed 18 pressure gauges in the vacuum vessel. This allowed us to determine the exhaust efficiency, the leakage, the collection efficiency and the compression ratio of the island divertor. These quantities depended strongly on the magnetic configuration. The best performance was obtained in the high-iota configuration. The exhaust efficiency was 2.9%, significantly higher than in the standard configuration (0.44%), and the maximum neutral compression was about 80. The high-iota configuration appears particularly promising for long-pulse operation of W7-X.

Published
2022
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8. 2D measurements of parallel counter-streaming flows in the W7-X scrape-off layer for attached and detached plasmas

Author

W7-X Team, Perseo, V., Winters, V., Feng, Y., Reimold, F., Ford, O. P., König, R., Bozhenkov, S. A., Brunner, K. J., Burhenn, R., Drewelow, P., Ennis, D. A., Gao, Y., Gradic, D., Hacker, P., Hergenhahn, U., Jakubowski, M. W., Knauer, J., Kremeyer, T., Kriete, D. M., Krychowiak, M., Kwak, S., Niemann, H., Pavone, A., Pisano, F., Puig Sitjes, A., Schlisio, G., Svensson, J., Zhang, D., Sunn Pedersen, T., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Physics, Technology, Nuclear and High Energy Physics, 0103 physical sciences, Plasma, 010306 general physics, Condensed Matter Physics, ddc:600, 01 natural sciences, Layer (electronics), 010305 fluids & plasmas, Computational physics
Abstract

Investigations of particle parallel flow velocities have been carried out for the scrape-off layer (SOL) of the Wendelstein 7-X (W7-X) stellarator, in order to gain insights on the SOL transport properties during attached and detached plasma scenarios. The experimental evidence is based on the coherence imaging spectroscopy (CIS) diagnostic, able to measure 2D impurity emission intensity and flow velocity. The impurity monitored by CIS is C2+, characterized by a line-emission intensity observed to be linearly proportional to the total plasma radiated power in both attached and detached plasmas. The related C2+ velocity shows a strong dependence on the line-averaged electron density while remaining insensitive to the input power. During attached plasmas, the velocity increases with increasing line-averaged density. The tendency reverses in the transition to and during detachment, in which the velocity decreases by at least a factor of 2. The sharp drop in velocity, together with a rise in line-emission intensity, is reliably correlated to the detachment transition and can therefore be used as one of its signatures. The impurity flow velocity appears to be well coupled with the main ions’ one, thus implying the dominant role of impurity-main ion friction in the parallelimpurity transport dynamics. In view of this SOL impurity transport regime, the CIS measurement results are here interpreted with the help of EMC3-Eirene simulations, and their major trends are already explainable with a simple 1D fluid model.

Published
2021

9. Plasma radiation behavior approaching high-radiation scenarios in W7-X

Author

W7-X Team, Zhang, D., Burhenn, R., Feng, Y., König, R., Buttenschön, B., Beidler, C. D., Hacker, P., Reimold, F., Thomsen, H., Laube, R., Klinger, T., Giannone, L., Penzel, F., Pavone, A., Krychowiak, M., Beurskens, M., Bozhenkov, S., Brunner, J. K., Effenberg, F., Fuchert, G., Gao, Y., Geiger, J., Hirsch, M., Höfel, U., Jakubowski, M., Knauer, J., Kwak, S., Laqua, H. P., Niemann, H., Otte, M., Pedersen, T. Sunn, Pasch, E., Pablant, N., Rahbarnia, K., Svensson, J., Blackwell, B., Drews, P., Endler, M., Rudischhauser, L., Wang, E., Weir, G., Winters, V., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Physics, Nuclear and High Energy Physics, Technology, business.industry, High radiation, Plasma radiation, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Optics, 0103 physical sciences, ddc:620, 010306 general physics, business, ddc:600
Abstract

The W7-X stellarator has so far performed experiments under both limiter and divertor conditions. The plasma is mostly generated by ECR-heating with powers up to 6.5 MW, and the plasma density is usually limited by the radiation losses from low-Z impurities (such as carbon and oxygen) released mainly from the graphite targets. The present work first summarizes the radiation loss fractions f rad achieved in quasi-stationary hydrogen plasmas in both operational phases, and then shows how impurity radiation behaves differently with the two different boundary conditions as the plasma density increases. The divertor operation is emphasized and some beneficial effects (with respect to impurity radiation) are highlighted: (1) intensive radiation is located at the edge (r/a > 0.8) even at high radiation loss fractions, (2) the plasma remains stable up to f rad approaching unity, (3) the reduction in the stored energy is about 10% for high f rad scenarios. Moreover, effects of wall boronisation on impurity radiation profiles are also presented.

Published
2021

12. Demonstration of reduced neoclassical energy transport in Wendelstein 7-X

Author

W7-X Team, Beidler, C. D., Smith, H. M., Alonso, A., Andreeva, T., Baldzuhn, J., Beurskens, M. N. A., Borchardt, M., Bozhenkov, S. A., Brunner, K. J., Damm, H., Drevlak, M., Ford, O. P., Fuchert, G., Geiger, J., Helander, P., Hergenhahn, U., Hirsch, M., Höfel, U., Kazakov, Ye. O., Kleiber, R., Krychowiak, M., Kwak, S., Langenberg, A., Laqua, H. P., Neuner, U., Pablant, N. A., Pasch, E., Pavone, A., Pedersen, T. S., Rahbarnia, K., Schilling, J., Scott, E. R., Stange, T., Svensson, J., Thomsen, H., Turkin, Y., Warmer, F., Wolf, R. C., Zhang, D., Abramovic, I., Äkäslompolo, S., Alcusón, J., Aleynikov, P., Aleynikova, K., Ali, A., Anda, G., Ascasibar, E., Bähner, J. P., Baek, S. G., Balden, M., Banduch, M., Barbui, T., Behr, W., Benndorf, A., Biedermann, C., Biel, W., Blackwell, B., Blanco, E., Blatzheim, M., Ballinger, S., Bluhm, T., Böckenhoff, D., Böswirth, B., Böttger, L.-G., Borsuk, V., Boscary, J., Bosch, H.-S., Brakel, R., Brand, H., Brandt, C., Bräuer, T., Braune, H., Brezinsek, S., Brunner, K.-J., Burhenn, R., Bussiahn, R., Buttenschön, B., Bykov, V., Cai, J., Calvo, I., Cannas, B., Cappa, A., Carls, A., Carraro, L., Carvalho, B., Castejon, F., Charl, A., Chaudhary, N., Chauvin, D., Chernyshev, F., Cianciosa, M., Citarella, R., Claps, G., Coenen, J., Cole, M., Cole, M. J., Cordella, F., Cseh, G., Czarnecka, A., Czerski, K., Czerwinski, M., Czymek, G., Molin, A. da, Silva, A. da, Pena, A. de la, Degenkolbe, S., Dhard, C. P., Dibon, M., Dinklage, A., Dittmar, T., Drewelow, P., Drews, P., Durodie, F., Edlund, E., Effenberg, F., Ehrke, G., Elgeti, S., Endler, M., Ennis, D., Esteban, H., Estrada, T., Fellinger, J., Feng, Y., Flom, E., Fernandes, H., Fietz, W. H., Figacz, W., Fontdecaba, J., Fornal, T., Frerichs, H., Freund, A., Funaba, T., Galkowski, A., Gantenbein, G., Gao, Y., García Regaña, J., Gates, D., Geiger, B., Giannella, V., Gogoleva, A., Goncalves, B., Goriaev, A., Gradic, D., Grahl, M., Green, J., Greuner, H., Grosman, A., Grote, H., Gruca, M., Grulke, O., Guerard, C., Hacker, P., Han, X., Harris, J. H., Hartmann, D., Hathiramani, D., Hein, B., Heinemann, B., Henneberg, S., Henkel, M., Hernandez Sanchez, J., Hidalgo, C., Hollfeld, K. P., Hölting, A., Höschen, D., Houry, M., Howard, J., Huang, X., Huang, Z., Hubeny, M., Huber, M., Hunger, H., Ida, K., Ilkei, T., Illy, S., Israeli, B., Jablonski, S., Jakubowski, M., Jelonnek, J., Jenzsch, H., Jesche, T., Jia, M., Junghanns, P., Kacmarczyk, J., Kallmeyer, J.-P., Kamionka, U., Kasahara, H., Kasparek, W., Kenmochi, N., Killer, C., Kirschner, A., Klinger, T., Knauer, J., Knaup, M., Knieps, A., Kobarg, T., Kocsis, G., Köchl, F., Kolesnichenko, Y., Könies, A., König, R., Kornejew, P., Koschinsky, J.-P., Köster, F., Krämer, M., Krampitz, R., Krämer-Flecken, A., Krawczyk, N., Kremeyer, T., Krom, J., Ksiazek, I., Kubkowska, M., Kühner, G., Kurki-Suonio, T., Kurz, P. A., Landreman, M., Lang, P., Lang, R., Langish, S., Laqua, H., Laube, R., Lazerson, S., Lechte, C., Lennartz, M., Leonhardt, W., Li, C., Li, Y., Liang, Y., Linsmeier, C., Liu, S., Lobsien, J.-F., Loesser, D., Loizu Cisquella, J., Lore, J., Lorenz, A., Losert, M., Lücke, A., Lumsdaine, A., Lutsenko, V., Maaßberg, H., Marchuk, O., Matthew, J. H., Marsen, S., Marushchenko, M., Masuzaki, S., Maurer, D., Mayer, M., McCarthy, K., McNeely, P., Meier, A., Mellein, D., Mendelevitch, B., Mertens, P., Mikkelsen, D., Mishchenko, A., Missal, B., Mittelstaedt, J., Mizuuchi, T., Mollen, A., Moncada, V., Mönnich, T., Morisaki, T., Moseev, D., Murakami, S., Náfrádi, G., Nagel, M., Naujoks, D., Neilson, H., Neu, R., Neubauer, O., Ngo, T., Nicolai, D., Nielsen, S. K., Niemann, H., Nishizawa, T., Nocentini, R., Nührenberg, C., Nührenberg, J., Obermayer, S., Offermanns, G., Ogawa, K., Ölmanns, J., Ongena, J., Oosterbeek, J. W., Orozco, G., Otte, M., Pacios Rodriguez, L., Panadero, N., Panadero Alvarez, N., Papenfuß, D., Paqay, S., Pawelec, E., Pelka, G., Perseo, V., Peterson, B., Pilopp, D., Pingel, S., Pisano, F., Plaum, B., Plunk, G., Pölöskei, P., Porkolab, M., Proll, J., Puiatti, M.-E., Puig Sitjes, A., Purps, F., Rack, M., Récsei, S., Reiman, A., Reimold, F., Reiter, D., Remppel, F., Renard, S., Riedl, R., Riemann, J., Risse, K., Rohde, V., Röhlinger, H., Romé, M., Rondeshagen, D., Rong, P., Roth, B., Rudischhauser, L., Rummel, K., Rummel, T., Runov, A., Rust, N., Ryc, L., Ryosuke, S., Sakamoto, R., Salewski, M., Samartsev, A., Sanchez, M., Sano, F., Satake, S., Schacht, J., Satheeswaran, G., Schauer, F., Scherer, T., Schlaich, A., Schlisio, G., Schluck, F., Schlüter, K.-H., Schmitt, J., Schmitz, H., Schmitz, O., Schmuck, S., Schneider, M., Schneider, W., Scholz, P., Schrittwieser, R., Schröder, M., Schröder, T., Schroeder, R., Schumacher, H., Schweer, B., Sereda, S., Shanahan, B., Sibilia, M., Sinha, P., Sipliä, S., Slaby, C., Sleczka, M., Spiess, W., Spong, D. A., Spring, A., Stadler, R., Stejner, M., Stephey, L., Stridde, U., Suzuki, C., Szabó, V., Szabolics, T., Szepesi, T., Szökefalvi-Nagy, Z., Tamura, N., Tancetti, A., Terry, J., Thomas, J., Thumm, M., Travere, J. M., Traverso, P., Tretter, J., Trimino Mora, H., Tsuchiya, H., Tsujimura, T., Tulipán, S., Unterberg, B., Vakulchyk, I., Valet, S., Vanó, L., Eeten, P. van, Milligen, B. van, Vuuren, A. J. van, Vela, L., Velasco, J.-L., Vergote, M., Vervier, M., Vianello, N., Viebke, H., Vilbrandt, R., Stechow, A. von, Vorköper, A., Wadle, S., Wagner, F., Wang, E., Wang, N., Wang, Z., Wauters, T., Wegener, L., Weggen, J., Wegner, T., Wei, Y., Weir, G., Wendorf, J., Wenzel, U., Werner, A., White, A., Wiegel, B., Wilde, F., Windisch, T., Winkler, M., Winter, A., Winters, V., Wolf, S., Wright, A., Wurden, G., Xanthopoulos, P., Yamada, H., Yamada, I., Yasuhara, R., Yokoyama, M., Zanini, M., Zarnstorff, M., Zeitler, A., Zhang, H., Zhu, J., Zilker, M., Zocco, A., Zoletnik, S., Zuin, M., W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society, Applied Physics and Science Education, Science and Technology of Nuclear Fusion, Turbulence in Fusion Plasmas, and European Commission

Subjects
Magnetically Confined Plasmas, Tokamak, Design, Helias, Nuclear engineering, Magnetically confined plasmas, 01 natural sciences, 7. Clean energy, Article, Plasma physics, 010305 fluids & plasmas, law.invention, law, Physics::Plasma Physics, 0103 physical sciences, Nuclear fusion, 010306 general physics, Engineering & allied operations, Stellarator, Physics, Plasma fusion, Multidisciplinary, Toroid, biology, Plasma Physics, Física, Magnetic confinement fusion, Plasma, biology.organism_classification, Energía Nuclear, ddc:620, Wendelstein 7-X
Abstract

Research on magnetic confinement of high-temperature plasmas has the ultimate goal of harnessing nuclear fusion for the production of electricity. Although the tokamak1 is the leading toroidal magnetic-confinement concept, it is not without shortcomings and the fusion community has therefore also pursued alternative concepts such as the stellarator. Unlike axisymmetric tokamaks, stellarators possess a three-dimensional (3D) magnetic field geometry. The availability of this additional dimension opens up an extensive configuration space for computational optimization of both the field geometry itself and the current-carrying coils that produce it. Such an optimization was undertaken in designing Wendelstein 7-X (W7-X)2, a large helical-axis advanced stellarator (HELIAS), which began operation in 2015 at Greifswald, Germany. A major drawback of 3D magnetic field geometry, however, is that it introduces a strong temperature dependence into the stellarator’s non-turbulent ‘neoclassical’ energy transport. Indeed, such energy losses will become prohibitive in high-temperature reactor plasmas unless a strong reduction of the geometrical factor associated with this transport can be achieved; such a reduction was therefore a principal goal of the design of W7-X. In spite of the modest heating power currently available, W7-X has already been able to achieve high-temperature plasma conditions during its 2017 and 2018 experimental campaigns, producing record values of the fusion triple product for such stellarator plasmas3,4. The triple product of plasma density, ion temperature and energy confinement time is used in fusion research as a figure of merit, as it must attain a certain threshold value before net-energy-producing operation of a reactor becomes possible1,5. Here we demonstrate that such record values provide evidence for reduced neoclassical energy transport in W7-X, as the plasma profiles that produced these results could not have been obtained in stellarators lacking a comparably high level of neoclassical optimization., Previously documented record values of the fusion triple product in the stellarator Wendelstein 7-X are shown to be evidence for reduced neoclassical energy transport in this optimized device.

Published
2021

13. Plasma-Surface Interaction in the Stellarator W7-X: Conclusion drawn from operation with Graphite Plasma-Facing Components

Author

Brezinsek, S., Jakubowski, M., Dhard, C. P., Dittmar, T., Drews, P., Effenberg, F., Ford, O., Fortuna-Zalesna, E., Gao, Y., Goriaev, A., Hakola, A., Kremeyer, T., König, R., Krychowiak, M., Motojima, G., Neu, R., Olemann, J., Neubauer, O., Petersson, P., Rasinski, M., Romazanov, J., Rubel, M., Schmid, K., Masuzaki, S., Sereda, S., Wang, E., Wauters, T., Winters, V., Yi, R., Zhao, Dongye, Mayer, M., Naujoks, D., Schmitz, O., Balden, M., Brakel, R., and Butterschön, B.

Published
2021

14. EMC3-EIRENE simulation of first wall recycling fluxes in W7-X with relation to H-alpha measurements

Author

W7-X Team, Winters, V. R., Reimold, F., König, R., Krychowiak, M., Romba, T., Biedermann, C., Bozhenkov, S., Drewelow, P., Endler, M., Feng, Y., Frerichs, H., Fuchert, G., Geiger, J., Gao, Y., Harris, J. H., Jakubowski, M., Kornejew, P., Kremeyer, T., Niemann, H., Pasch, E., Puig-Sitjes, A., Schlisio, G., Scott, E. R., Wurden, G. A., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Technology, Materials science, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Nuclear Energy and Engineering, law, 0103 physical sciences, H-alpha, Atomic physics, 010306 general physics, Spectroscopy, ddc:600, Stellarator
Abstract

In the Wendelstein 7-X stellarator, the main locations of particle sources are expected to be the carbon divertors, baffles and graphite heat shield first wall. In this paper, the heat shield is implemented in EMC3-EIRENE to understand the expected areas and magnitudes of the recycling flux to this component. It is found that in the simulation the heat shield is not a significant source of recycling neutrals. The areas of simulated recycling flux are shown to correlate well with footprints of plasma-wetting seen in post-experimental campaign in-vessel inspection photos. EMC3-EIRENE reconstruction of line-integrated H-alpha measurements at the heat shield indicate that the majority of emission does not come from local recycling neutrals. Rather, the H-alpha signals at the heat shield are dominated by ionization of neutrals which have leaked from the divertor/baffle region into the midplane. The magnitude of the H-alpha line emission from the synthetic reconstruction is consistent with the experiment, indicating that a large overestimation of heat shield recycling would occur if these measurements were assumed to be from local recycling sources. In the future, it may be possible to obtain some information of local recycling from the heat shield since it was found that the majority of the recycling flux occurs on two well-localized areas.

Published
2021

15. Plasma radiation behavior approaching high-radiation scenarios in W7-X

Author

Zhang, D., Burhenn, R., Feng, Y., K��nig, R., Buttensch��n, B., Beidler, C.D., Hacker, P., Reimold, F., Thomsen, H., Laube, R., Klinger, T., Giannone, L., Penzel, F., Pavone, A., Krychowiak, M., Beurskens, M., Bozhenkov, S., Brunner, J.K., Effenberg, F., Fuchert, G., Gao, Y., Geiger, J., Hirsch, M., H��fel, U., Jakubowski, M., Knauer, J., Kwak, S., Laqua, H.P., Niemann, H., Otte, M., Pedersen, T. Sunn, Pasch, E., Pablant, N., Rahbarnia, K., Svensson, J., Blackwell, B., Drews, P., Endler, M., Rudischhauser, L., Wang, E., Weir, G., Winters, V., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfu��, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, and Weggen, J��rg

Published
2021
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16. Publisher Correction: Demonstration of reduced neoclassical energy transport in Wendelstein 7-X

Author

Beidler, C. D., Smith, H. M., Alonso, A., Andreeva, T., Baldzuhn, J., Beurskens, M. N. A., Borchardt, M., Bozhenkov, S. A., Brunner, K. J., Damm, H., Drevlak, M., Ford, O. P., Fuchert, G., Geiger, J., Helander, P., Hergenhahn, U., Hirsch, M., H��fel, U., Kazakov, Ye. O., Kleiber, R., Krychowiak, M., Kwak, S., Langenberg, A., Laqua, H. P., Neuner, U., Pablant, N. A., Pasch, E., Pavone, A., Pedersen, T. S., Rahbarnia, K., Schilling, J., Scott, E. R., Stange, T., Svensson, J., Thomsen, H., Turkin, Y., Warmer, F., Wolf, R. C., Zhang, D., Abramovic, I., ��k��slompolo, S., Alcus��n, J., Aleynikov, P., Aleynikova, K., Ali, A., Anda, G., Ascasibar, E., B��hner, J. P., Baek, S. G., Balden, M., Banduch, M., Barbui, T., Behr, W., Benndorf, A., Biedermann, C., Biel, W., Blackwell, B., Blanco, E., Blatzheim, M., Ballinger, S., Bluhm, T., B��ckenhoff, D., B��swirth, B., B��ttger, L.-G., Borsuk, V., Boscary, J., Bosch, H.-S., Brakel, R., Brand, H., Brandt, C., Br��uer, T., Braune, H., Brezinsek, S., Brunner, K.-J., Burhenn, R., Bussiahn, R., Buttensch��n, B., Bykov, V., Cai, J., Calvo, I., Cannas, B., Cappa, A., Carls, A., Carraro, L., Carvalho, B., Castejon, F., Charl, A., Chaudhary, N., Chauvin, D., Chernyshev, F., Cianciosa, M., Citarella, R., Claps, G., Coenen, J., Cole, M., Cole, M. J., Cordella, F., Cseh, G., Czarnecka, A., Czerski, K., Czerwinski, M., Czymek, G., Da Molin, A., Da Silva, A., De La Pena, A., Degenkolbe, S., Dhard, C. P., Dibon, M., Dinklage, A., Dittmar, T., Drewelow, P., Drews, P., Durodie, F., Edlund, E., Effenberg, F., Ehrke, G., Elgeti, S., Endler, M., Ennis, D., Esteban, H., Estrada, T., Fellinger, J., Feng, Y., Flom, E., Fernandes, H., Fietz, W. H., Figacz, W., Fontdecaba, J., Fornal, T., Frerichs, H., Freund, A., Funaba, T., Galkowski, A., Gantenbein, G., Gao, Y., Garc��a Rega��a, J., Gates, D., Geiger, B., Giannella, V., Gogoleva, A., Goncalves, B., Goriaev, A., Gradic, D., Grahl, M., Green, J., Greuner, H., Grosman, A., Grote, H., Gruca, M., Grulke, O., Guerard, C., Hacker, P., Han, X., Harris, J. H., Hartmann, D., Hathiramani, D., Hein, B., Heinemann, B., Henneberg, S., Henkel, M., Hernandez Sanchez, J., Hidalgo, C., Hollfeld, K. P., H��lting, A., H��schen, D., Houry, M., Howard, J., Huang, X., Huang, Z., Hubeny, M., Huber, M., Hunger, H., Ida, K., Ilkei, T., Illy, S., Israeli, B., Jablonski, S., Jakubowski, M., Jelonnek, J., Jenzsch, H., Jesche, T., Jia, M., Junghanns, P., Kacmarczyk, J., Kallmeyer, J.-P., Kamionka, U., Kasahara, H., Kasparek, W., Kenmochi, N., Killer, C., Kirschner, A., Klinger, T., Knauer, J., Knaup, M., Knieps, A., Kobarg, T., Kocsis, G., K��chl, F., Kolesnichenko, Y., K��nies, A., K��nig, R., Kornejew, P., Koschinsky, J.-P., K��ster, F., Kr��mer, M., Krampitz, R., Kr��mer-Flecken, A., Krawczyk, N., Kremeyer, T., Krom, J., Ksiazek, I., Kubkowska, M., K��hner, G., Kurki-Suonio, T., Kurz, P. A., Landreman, M., Lang, P., Lang, R., Langish, S., Laqua, H., Laube, R., Lazerson, S., Lechte, C., Lennartz, M., Leonhardt, W., Li, C., Li, Y., Liang, Y., Linsmeier, C., Liu, S., Lobsien, J.-F., Loesser, D., Loizu Cisquella, J., Lore, J., Lorenz, A., Losert, M., L��cke, A., Lumsdaine, A., Lutsenko, V., Maa��berg, H., Marchuk, O., Matthew, J. H., Marsen, S., Marushchenko, M., Masuzaki, S., Maurer, D., Mayer, M., McCarthy, K., McNeely, P., Meier, A., Mellein, D., Mendelevitch, B., Mertens, P., Mikkelsen, D., Mishchenko, A., Missal, B., Mittelstaedt, J., Mizuuchi, T., Mollen, A., Moncada, V., M��nnich, T., Morisaki, T., Moseev, D., Murakami, S., N��fr��di, G., Nagel, M., Naujoks, D., Neilson, H., Neu, R., Neubauer, O., Ngo, T., Nicolai, D., Nielsen, S. K., Niemann, H., Nishizawa, T., Nocentini, R., N��hrenberg, C., N��hrenberg, J., Obermayer, S., Offermanns, G., Ogawa, K., ��lmanns, J., Ongena, J., Oosterbeek, J. W., Orozco, G., Otte, M., Pacios Rodriguez, L., Panadero, N., Panadero Alvarez, N., Papenfu��, D., Paqay, S., Pawelec, E., Pelka, G., Perseo, V., Peterson, B., Pilopp, D., Pingel, S., Pisano, F., Plaum, B., Plunk, G., P��l��skei, P., Porkolab, M., Proll, J., Puiatti, M.-E., Puig Sitjes, A., Purps, F., Rack, M., R��csei, S., Reiman, A., Reimold, F., Reiter, D., Remppel, F., Renard, S., Riedl, R., Riemann, J., Risse, K., Rohde, V., R��hlinger, H., Rom��, M., Rondeshagen, D., Rong, P., Roth, B., Rudischhauser, L., Rummel, K., Rummel, T., Runov, A., Rust, N., Ryc, L., Ryosuke, S., Sakamoto, R., Salewski, M., Samartsev, A., S��nchez, E., Sano, F., Satake, S., Schacht, J., Satheeswaran, G., Schauer, F., Scherer, T., Schlaich, A., Schlisio, G., Schluck, F., Schl��ter, K.-H., Schmitt, J., Schmitz, H., Schmitz, O., Schmuck, S., Schneider, M., Schneider, W., Scholz, P., Schrittwieser, R., Schr��der, M., Schr��der, T., Schroeder, R., Schumacher, H., Schweer, B., Sereda, S., Shanahan, B., Sibilia, M., Sinha, P., Sipli��, S., Slaby, C., Sleczka, M., Spiess, W., Spong, D. A., Spring, A., Stadler, R., Stejner, M., Stephey, L., Stridde, U., Suzuki, C., Szab��, V., Szabolics, T., Szepesi, T., Sz��kefalvi-Nagy, Z., Tamura, N., Tancetti, A., Terry, J., Thomas, J., Thumm, M., Travere, J. M., Traverso, P., Tretter, J., Trimino Mora, H., Tsuchiya, H., Tsujimura, T., Tulip��n, S., Unterberg, B., Vakulchyk, I., Valet, S., Van��, L., Van Eeten, P., Van Milligen, B., Van Vuuren, A. J., Vela, L., Velasco, J.-L., Vergote, M., Vervier, M., Vianello, N., Viebke, H., Vilbrandt, R., Von Stechow, A., Vork��per, A., Wadle, S., Wagner, F., Wang, E., Wang, N., Wang, Z., Wauters, T., Wegener, L., Weggen, J., Wegner, T., Wei, Y., Weir, G., Wendorf, J., Wenzel, U., Werner, A., White, A., Wiegel, B., Wilde, F., Windisch, T., Winkler, M., Winter, A., Winters, V., Wolf, S., Wright, A., Wurden, G., Xanthopoulos, P., Yamada, H., Yamada, I., Yasuhara, R., Yokoyama, M., Zanini, M., Zarnstorff, M., Zeitler, A., Zhang, H., Zhu, J., Zilker, M., Zocco, A., Zoletnik, S., and Zuin, M.

Subjects
Chemical engineering, ddc:660
Published
2021

18. Increasing the density in Wendelstein 7-X: benefits and limitations

Author

W7-X Team, Fuchert, G., Brunner, K. J., Rahbarnia, K., Stange, T., Zhang, D., Baldzuhn, J., Bozhenkov, S. A., Beidler, C. D., Beurskens, M. N. A., Brezinsek, S., Burhenn, R., Damm, H., Dinklage, A., Feng, Y., Hacker, P., Hirsch, M., Kazakov, Y., Knauer, J., Langenberg, A., Laqua, H. P., Lazerson, S., Pablant, N. A., Pasch, E., Reimold, F., Sunn Pedersen, T., Scott, E. R., Warmer, F., Winters, V. R., Wolf, R. C., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Physics, Technology, Nuclear and High Energy Physics, Range (particle radiation), Divertor, Plasma, Radiation, Condensed Matter Physics, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, law.invention, Computational physics, law, 0103 physical sciences, Radiative transfer, ddc:620, Wendelstein 7-X, 010306 general physics, ddc:600, Energy (signal processing), Stellarator
Abstract

In stellarators, increasing the density is beneficial for the energy confinement. While there is no single reason for this observation, it is still very robust across different devices and this is reflected in the empirical energy confinement time scaling for stellarators, ISS04. In order to study whether this is also true for Wendelstein 7-X, the density scaling of the energy confinement time is analyzed and compared to ISS04 for the first divertor experiments. When the density is increased beyond a critical density, however, radiative collapses are frequently observed. Existing analytical models for the critical density are revisited to assess whether they can predict the accessible density range. Furthermore, since close to the collapse the radiation losses increase substantially, the impact on the global energy confinement is investigated. It is found that in plasmas with high radiation the density scaling of the energy confinement time becomes weaker, the reason for this observation is not yet clear. In the second half of the first divertor campaign, boronization was applied to W7-X for the first time. This broadened the operational window, allowing for operation at higher density and, hence, higher stored energy.

Published
2020

19. Enhanced energy confinement after series of pellets in Wendelstein 7-X

Author

W7-X Team, Baldzuhn, J., Damm, H., Beidler, C. D., McCarthy, K., Panadero, N., Biedermann, C., Bozhenkov, S. A., Dinklage, A., Brunner, K. J., Fuchert, G., Kazakov, Y., Beurskens, M., Dibon, M., Geiger, J., Grulke, O., Höfel, U., Klinger, T., Köchl, F., Knauer, J., Kocsis, G., Kornejew, P., Lang, P. T., Langenberg, A., Laqua, H., Pablant, N. A., Pasch, E., Pedersen, T. S., Ploeckl, B., Rahbarnia, K., Schlisio, G., Scott, E. R., Stange, T., Von Stechow, A., Szepesi, T., Turkin, Y., Wagner, F., Winters, V., Wurden, G., Zhang, D., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Technology, Materials science, Series (mathematics), Pellets, Plasma, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Nuclear Energy and Engineering, Impurity, 0103 physical sciences, Wendelstein 7-X, Atomic physics, 010306 general physics, ddc:600, Energy (signal processing)
Abstract

A series of ice pellets was injected into the advanced stellarator Wendelstein 7-X (W7-X). Although the pellets were small and slow, deep and efficient particle fueling could be observed experimentally. The most striking feature appearing after the injection of the pellets, however, was a transient increase in the energy confinement time. This transient phase resembled in several aspects modes of enhanced confinement after gas-puff or pellet injection, as observed in other fusion experiments. All experimental attempts, to prolong this phase, failed. In this paper, discharges are described that show the enhanced energy confinement, and some conditions are summarized which seem to be essential in order to generate it. The focus here is on deep particle fueling by pellets, and shaping of the density profiles during and after the series of pellets. During this time, neutral gas particle re-fueling at the plasma edge is reduced, while density profile peaking and low impurity radiation losses are present.

Published
2020

20. Enhanced energy confinement after series of pellets in Wendelstein 7-X

Author

Baldzuhn, J, Damm, H, Beidler, C D, McCarthy, K, Panadero, N, Biedermann, C, Bozhenkov, S A, Dinklage, A, Brunner, K J, Fuchert, G, Kazakov, Y, Beurskens, M, Dibon, M, Geiger, J, Grulke, O, Höfel, U, Klinger, T, Köchl, F, Knauer, J, Kocsis, G, Kornejew, P, Lang, P T, Langenberg, A, Laqua, H, Pablant, N A, Pasch, E, Pedersen, T S, Ploeckl, B, Rahbarnia, K, Schlisio, G, Scott, E R, Stange, T, Von Stechow, A, Szepesi, T, Turkin, Y, Wagner, F, Winters, V, Wurden, G, Zhang, D., Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, and Weggen, Jörg

Published
2020
Full Text
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22. Increasing the Density in W7-X: Benefits and Limitations

Author

Fuchert, G., Brunner, K., Rahbarnia, K., Stange, T., Zhang, D., Baldzuhn, J., Bozhenkov, S., Beidler, C., Brezinsek, S., Burhenn, R., Damm, H., Dinklage, A., Hirsch, M., Kazakov, Y., Knauer, J., Feng, Y., Langenberg, A., Laqua, H., Lazerson, S., Pablant, N., Pasch, E., Pedersen, T., Scott, E., Warmer, F., Winters, V., Wolf, R., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Published
2019

23. Demonstration of Power Exhaust Control by Impurity Seeding in the Island Divertor at Wendelstein 7-X

Author

Effenberg, F., Brezinsek, S., Feng, Y., Jakubowski, M., König, R., Krychowiak, M., Schmitz, O., Suzuki, Y., Zhang, D., Ali, A., Barbui, T., Biedermann, C., Blackwell, D., Burhenn, R., Cseh, G., Dittmar, T., Drewelow, P., Endler, M., Frerichs, H., Gao, Y., Geiger, J., Hammond, K., Killer, C., Kocsis, G., Lore, J., Niemann, H., Otte, M., Puig Sitjes, A., Rudischhauser, L., Schmitt, J., Pedersen, T., Szepesi, T., Wenzel, U., Winters, V., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Published
2019

24. First Divertor Physics Studies in Wendelstein 7-X

Author

Pedersen, T., König, R., Jakubowski, M., Feng, Y., Ali, A., Anda, G., Baldzuhn, J., Barbui, T., Biedermann, C., Blackwell, B., Bosch, H., Bozhenkov, S., Brakel, R., Brezinsek, S., Cai, J., Coenen, J., Cosfeld, J., Dinklage, A., Dittmar, T., Drewelow, P., Drews, P., Dunai, D., Effenberg, F., Endler, M., Fellinger, J., Ford, O., Frerichs, H., Fuchert, G., Geiger, J., Gao, Y., Goriaev, A., Henkel, M., Hammond, K., Harris, J., Hathiramani, D., Hölbe, H., Kazakov, Y., Killer, C., Kirschner, A., Knieps, A., Kobayashi, M., Kornejew, P., Krychowiak, M., Kocsis, G., Lazerzon, S., Li, C., Li, Y., Liang, Y., Liu, S., Lore, J., Masuzaki, S., Moncada, V., Neubauer, O., Ngo, T., Niemann, H., Oelmann, J., Otte, M., Perseo, V., Pisano, F., Puig Sitjes, A., Rack, M., Rasinski, M., Romazanov, J., Rudischhauser, L., Schmitt, J., Schlisio, G., Schmitz, O., Schweer, B., Sereda, S., Szepesi, T., Suzuki, Y., Wang, E., Wei, Y., Wenzel, U., Wiesen, S., Winters, V., Wauters, T., Wurden, G., Zhang, D., Zoletnik, S., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Published
2019

25. Pellet fueling experiments in Wendelstein 7-X

Author

W7-X Team, Baldzuhn, J., Damm, H., Beidler, C. D., McCarthy, K., Panadero, N., Biedermann, C., Bozhenkov, S. A., Brunner, K. J., Fuchert, G., Kazakov, Y., Beurskens, M., Dibon, M., Geiger, J., Grulke, O., Höfel, U., Klinger, T., Köchl, F., Knauer, J., Kocsis, G., Kornejew, P., Lang, P. T., Langenberg, A., Laqua, H., Pablant, N. A., Pasch, E., Pedersen, T. S., Ploeckl, B., Rahbarnia, K., Schlisio, G., Scott, E. R., Stange, T., Stechow, A. von, Szepesi, T., Turkin, Y., Wagner, F., Winters, V., Wurden, G., Zhang, D., Gantenbein, Gerd, Huber, Martina, Hunger, Hermann, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Losert, M., Meier, A., Mellein, Daniel, Papenfuß, Daniel, Samartsev, Andrey, Scherer, Theo, Schlaich, A., Spiess, W., Thumm, Manfred, Wadle, Simone, and Weggen, Jörg

Subjects
Technology, ddc:600
Published
2019

26. Structure of island localized modes in Wendelstein 7-X1

Author

Wurden, G. A., Andreeva, T., Hammond, K., Hirsch, M., H öfel, U., Killer, C., Kocsis, G., Kornejew, P., Krämer-Flecken, A., Krychowiak, M., Lazerson, S., Rahbarnia, K., Ballinger, S., Schilling, J., Szepesi, T., Thomsen, H., Winters, V., Zoletnik, S., the W7-X Team, Bozhenkov, S., Brandt, C., Buttenschoen, B., Damm, H., Endler, M., Freundt, S., and Geiger, J.

Published
2019

28. Demonstration of power exhaust control by impurity seeding in the island divertor at Wendelstein 7-X

Author

Effenberg, Florian, Brezinsek, Sebastijan, Feng, Y., Jakubowski, M., Koenig, R., Krychowiak, M., Schmitz, Oliver, Suzuki, Y., Zhang, D., Ali, A., Barbui, T., Biedermann, C., Blackwell, B.D., Cseh, C., Dittmar, T, Drewelow, P., Endler, M., Frerichs, H., Gao, Y., Geiger, J., Hammond, K., Killer, C., Kocsis, G., Lore, J.D., Niemann, H., Otte, M., Puig Sitjes, A., Rudischhauser, J., Schmitt, J.C., Pedersen, T. Sunn, Szepesi, T., Wenzel, U., Winters, V., and Effenberg, Florian

Subjects
EMC3-EIRENE, Detachment, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [SPI] Engineering Sciences [physics], [PHYS.PHYS.PHYS-COMP-PH] Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], Nuclear reactor, [SPI.PLASMA] Engineering Sciences [physics]/Plasmas, plasma fluid, 3D fields, 3D modeling, [PHYS.HIST] Physics [physics]/Physics archives, Plasma, Divertor, [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Nuclear fusion, [PHYS.PHYS] Physics [physics]/Physics [physics], Heat flux, Impurity transport, Stellarator
Abstract

Bei Wendelstein 7-X (W7-X) wurde erstmals eine effektive Leistungsabfuhr durch Verunreinigungsseeding und deren Abhängigkeit von der verwendeten Gasspezies in Inseldivertorkonfigurationen demonstriert. Während der ersten Insel-Divertor-Kampagne wurde systematisch eine Reihe von Experimenten durchgeführt, die zeigen, dass das Umschalten von Neon (Ne) auf Stickstoff (N2) als Verunreinigungsgas ein Umschalten von anhaltender zu kurzpulsigerer Randkühlung ermöglicht. Bei der Ne-Injektion wird aufgrund des hohen Recyclingverhaltens dieses Edelgases eine deutliche Verstärkung der Randstrahlung mit langsamem Abklingen nach Beendigung der Injektion beobachtet. Die Entladungen mit N2-Injektion zeigen eine Reaktion lokaler Plasmaparameter an den Divertorplatten, die meistens mit der Puffdauer korreliert. Eine schnelle Wiederherstullung von Te und ein Abfall von Prad nach dem Ende der Injektion deuten auf einen niedrigen Recyclingkoeffizienten für diese Verunreinigungsspezies hin. Die 3D-Modellierung dieser Effekte mit EMC3-EIRENE bestätigt, dass Ne im Vergleich zu N2 ein effektiverer Strahler ist., Effective power exhaust by impurity seeding and its dependence on the gas species used was demonstrated in island divertor configurations for the first time at Wendelstein 7-X (W7-X). A systematic set of experiments has been conducted during the first island divertor campaign which shows that switching from neon (Ne) to nitrogen (N2) as seeding gases enables switching from sustained to more short-pulse edge cooling. In the case of Ne seeding, significant enhancement of edge radiation with slow decay after the end of the injection is observed due to the high recycling properties of this noble gas. The N2 seeded discharges show the response of local plasma parameters at the divertor target mostly correlated to the puff duration. Fast Te recovery and drop of Prad after the end of the puff suggest a low recycling coefficient for this impurity species. 3D modeling of these effects with EMC3-EIRENE confirms that Ne is a more effective radiator compared to N2., L'épuisement efficace de la puissance par ensemencement d'impuretés et sa dépendance aux espèces de gaz utilisées ont été démontrés pour la première fois dans des configurations de divertor en îlot à Wendelstein 7-X (W7-X). Un ensemble systématique d'expériences a été mené au cours de la première campagne de divertor en îlot qui montre que le passage du néon (Ne) à l'azote (N2) comme gaz d'ensemencement permet de passer d'un refroidissement de bord soutenu à un refroidissement à impulsions plus courtes. Dans le cas de l'ensemencement de Ne, une amélioration significative du rayonnement de bord avec une décroissance lente après la fin de l'injection est observée en raison des propriétés de recyclage élevées de ce gaz rare. Les décharges ensemencées de N2 montrent la réponse des paramètres plasmatiques locaux au niveau de la cible du divertor principalement corrélée à la durée de la bouffée. La récupération rapide de Te et la chute de Prad après la fin de la bouffée suggèrent un faible coefficient de recyclage pour cette espèce d'impureté. La modélisation 3D de ces effets avec EMC3-EIRENE confirme que Ne est un radiateur plus efficace que N2.

Published
2018

29. Magnetic configuration effects on the Wendelstein 7-X stellarator

Author

Dinklage A., Beidler C.D., Helander P., Fuchert G., Maassberg H., Rahbarnia K., Sunn Pedersen T., Turkin Y., Wolf R.C., Alonso A., Andreeva T., Blackwell B., Bozhenkov S., Buttenschon B., Czarnecka A., Effenberg F., Feng Y., Geiger J., Hirsch M., Hofel U., Jakubowski M., Klinger T., Knauer J., Kocsis G., Kramer-Flecken A., Kubkowska M., Langenberg A., Laqua H.P., Marushchenko N., Mollen A., Neuner U., Niemann H., Pasch E., Pablant N., Rudischhauser L., Smith H.M., Schmitz O., Stange T., Szepesi T., Weir G., Windisch T., Wurden G.A., Zhang D., Abramovic I., Akaslompolo S., Ali A., Belloso J.A., Aleynikov P., Aleynikova K., Alzbutas R., Anda G., Ascasibar E., Assmann J., Baek S.-G., Baldzuhn J., Banduch M., Barbui T., Barlak M., Baumann K., Behr W., Beidler C., Benndorf A., Bertuch O., Beurskens M., Biedermann C., Biel W., Birus D., Blanco E., Blatzheim M., Bluhm T., Bockenhoff D., Bolgert P., Borchardt M., Borsuk V., Boscary J., Bosch H.-S., Bottger L.-G., Brakel R., Brand H., Brandt C., Brauer T., Braune H., Brezinsek S., Brunner K.-J., Brunner B., Burhenn R., Bussiahn R., Bykov V., Cai Y., Calvo I., Cannas B., Cappa A., Card A., Carls A., Carraro L., Carvalho B., Castejon F., Charl A., Chernyshev F., Cianciosa M., Citarella R., Ciupinski L., Claps G., Cole M.J., Cordella F., Cseh G., Czermak A., Czerski K., Czerwinski M., Czymek G., da Molin A., da Silva A., Dammertz G., de la Pena A., Degenkolbe S., Denner P., Dittmar T., Dhard C.P., Dostal M., Drevlak M., Drewelow P., Drews P., Dudek A., Dundulis G., Durodie F., van Eeten P., Ehrke G., Endler M., Ennis D., Erckmann E., Esteban H., Estrada T., Fahrenkamp N., Feist J.-H., Fellinger J., Fernandes H., Fietz W.H., Figacz W., Fontdecaba J., Ford O., Fornal T., Frerichs H., Freund A., Fuhrer M., Funaba T., Galkowski A., Gantenbein G., Gao Y., Regana J.G., Garcia-Munoz M., Gates D., Gawlik G., Geiger B., Giannella V., Gierse N., Gogoleva A., Goncalves B., Goriaev A., Gradic D., Grahl M., Green J., Grosman A., Grote H., Gruca M., Grulke O., Guerard C., Hacker P., Haiduk L., Hammond K., Han X., Harberts F., Harris J.H., Hartfuss H.-J., Hartmann D., Hathiramani D., Hein B., Heinemann B., Heitzenroeder P., Henneberg S., Hennig C., Sanchez J.H., Hidalgo C., Holbe H., Hollfeld K.P., Holting A., Hoschen D., Houry M., Howard J., Huang X., Huber M., Huber V., Hunger H., Ida K., Ilkei T., Illy S., Israeli B., Ivanov A., Jablonski S., Jagielski J., Jelonnek J., Jenzsch H., Junghans P., Kacmarczyk J., Kaliatka T., Kallmeyer J.-P., Kamionka U., Karalevicius R., Kasahara H., Kasparek W., Kazakov Y., Kenmochi N., Keunecke M., Khilchenko A., Killer C., Kinna D., Kleiber R., Knaup M., Knieps A., Kobarg T., Kochl F., Kolesnichenko Y., Konies A., Koppen M., Koshurinov J., Koslowski R., Konig R., Koster F., Kornejew P., Koziol R., Kramer M., Krampitz R., Kraszewsk P., Krawczyk N., Kremeyer T., Krings T., Krom J., Krychowiak M., Krzesinski G., Ksiazek I., Kuhner G., Kurki-Suonio T., Kwak S., Landreman M., Lang R., Langish S., Laqua H., Laube R., Lazerson S., Lechte C., Lennartz M., Leonhardt W., Lewerentz L., Liang Y., Linsmeier C., Liu S., Lobsien J.-F., Loesser D., Cisquella J.L., Lore J., Lorenz A., Losert M., Lubyako L., Lucke A., Lumsdaine A., Lutsenko V., Maisano-Brown J., Marchuk O., Mardenfeld M., Marek P., Marsen S., Marushchenko M., Masuzaki S., Maurer D., McCarthy K., McNeely P., Meier A., Mellein D., Mendelevitch B., Mertens P., Mikkelsen D., Mishchenko O., Missal B., Mittelstaedt J., Mizuuchi T., Moncada V., Monnich T., Morisaki T., Moseev D., Munk R., Murakami S., Musielok F., Nafradi G., Nagel M., Naujoks D., Neilson H., Neubauer O., Ngo T., Nocentini R., Nuhrenberg C., Nuhrenberg J., Obermayer S., Offermanns G., Ogawa K., Ongena J., Oosterbeek J.W., Orozco G., Otte M., Rodriguez L.P., Pan W., Panadero N., Alvarez N.P., Panin A., Papenfuss D., Paqay S., Pavone A., Pawelec E., Pelka G., Peng X., Perseo V., Peterson B., Pieper A., Pilopp D., Pingel S., Pisano F., Plaum B., Plunk G., Povilaitis M., Preinhaelter J., Proll J., Puiatti M.-E., Sitjes A.P., Purps F., Rack M., Recsei S., Reiman A., Reiter D., Remppel F., Renard S., Riedl R., Riemann J., Rimkevicius S., Risse K., Rodatos A., Rohlinger H., Rome M., Rong P., Roscher H.-J., Roth B., Rummel K., Rummel T., Runov A., Rust N., Ryc L., Ryosuke S., Sakamoto R., Samartsev A., Sanchez M., Sano F., Satake S., Satheeswaran G., Schacht J., Schauer F., Scherer T., Schlaich A., Schlisio G., Schluter K.-H., Schmitt J., Schmitz H., Schmuck S., Schneider M., Schneider W., Scholz M., Scholz P., Schrittwieser R., Schroder M., Schroder T., Schroeder R., Schumacher H., Schweer B., Shanahan B., Shikhovtsev I.V., Sibilia M., Sinha P., Siplia S., Skodzik J., Slaby C., Smith H., Spiess W., Spong D.A., Spring A., Stadler R., Standley B., Stephey L., Stoneking M., Stridde U., Sulek Z., Pedersen T.S., Suzuki Y., Svensson J., Szabo V., Szabolics T., Szokefalvi-Nagy Z., Tamura N., Terra A., Terry J., Thomas J., Thomsen H., Thumm M., von Thun C.P., Timmermann D., Titus P., Toi K., Travere J.M., Traverso P., Tretter J., Mora H.T., Tsuchiya H., Tsujimura T., Tulipan S., Turnyanskiy M., Unterberg B., Urban J., Urbonavicius E., Vakulchyk I., Valet S., van Milligen B., Vela L., Velasco J.-L., Vergote M., Vervier M., Vianello N., Viebke H., Vilbrandt R., Vorkorper A., Wadle S., Wang E., Wang N., Warmer F., Wauters T., Wegener L., Weggen J., Wegner T., Wei Y., Wendorf J., Wenzel U., Wiegel B., Wilde F., Winkler E., Winters V., Wolf R., Wolf S., Wolowski J., Wright A., Wurden G., Xanthopoulos P., Yamada H., Yamada I., Yasuhara R., Yokoyama M., Zajac J., Zarnstorff M., Zeitler A., Zhang H., Zhu J., Zilker M., Zimbal A., Zocco A., Zoletnik S., Zuin M., W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society, Science and Technology of Nuclear Fusion, and Turbulence in Fusion Plasmas

Subjects
Physics, Tokamak, Field (physics), General Physics and Astronomy, Plasma, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, Bootstrap current, Computational physics, Magnetic field, law.invention, Magnetic mirror, Wendelstein 7-X stellarator, Physics and Astronomy (all), law, Physics::Plasma Physics, 0103 physical sciences, Wendelstein 7-X plasmas, Wendelstein 7-X, 010306 general physics, Stellarator
Abstract

The two leading concepts for confining high-temperature fusion plasmas are the tokamak and the stellarator. Tokamaks are rotationally symmetric and use a large plasma current to achieve confinement, whereas stellarators are non-axisymmetric and employ three-dimensionally shaped magnetic field coils to twist the field and confine the plasma. As a result, the magnetic field of a stellarator needs to be carefully designed to minimize the collisional transport arising from poorly confined particle orbits, which would otherwise cause excessive power losses at high plasma temperatures. In addition, this type of transport leads to the appearance of a net toroidal plasma current, the so-called bootstrap current. Here, we analyse results from the first experimental campaign of the Wendelstein 7-X stellarator, showing that its magnetic-field design allows good control of bootstrap currents and collisional transport. The energy confinement time is among the best ever achieved in stellarators, both in absolute figures (τE > 100 ms) and relative to the stellarator confinement scaling. The bootstrap current responds as predicted to changes in the magnetic mirror ratio. These initial experiments confirm several theoretically predicted properties of Wendelstein 7-X plasmas, and already indicate consistency with optimization measures. Results from the first experimental campaign of the Wendelstein 7-X stellarator demonstrate that its magnetic-field design grants good control of parasitic plasma currents, leading to long energy confinement times.

Published
2018

30. EMC3-EIRENE simulation of first wall recycling fluxes in W7-X with relation to H-alpha measurements.

Author

Winters, V R, Reimold, F, König, R, Krychowiak, M, Romba, T, Biedermann, C, Bozhenkov, S, Drewelow, P, Endler, M, Feng, Y, Frerichs, H, Fuchert, G, Geiger, J, Gao, Y, Harris, J H, Jakubowski, M, Kornejew, P, Kremeyer, T, Niemann, H, and Pasch, E

Subjects
*THERMAL shielding, *CALORIMETRY, *FLUX (Energy)
Abstract

In the Wendelstein 7-X stellarator, the main locations of particle sources are expected to be the carbon divertors, baffles and graphite heat shield first wall. In this paper, the heat shield is implemented in EMC3-EIRENE to understand the expected areas and magnitudes of the recycling flux to this component. It is found that in the simulation the heat shield is not a significant source of recycling neutrals. The areas of simulated recycling flux are shown to correlate well with footprints of plasma-wetting seen in post-experimental campaign in-vessel inspection photos. EMC3-EIRENE reconstruction of line-integrated H-alpha measurements at the heat shield indicate that the majority of emission does not come from local recycling neutrals. Rather, the H-alpha signals at the heat shield are dominated by ionization of neutrals which have leaked from the divertor/baffle region into the midplane. The magnitude of the H-alpha line emission from the synthetic reconstruction is consistent with the experiment, indicating that a large overestimation of heat shield recycling would occur if these measurements were assumed to be from local recycling sources. In the future, it may be possible to obtain some information of local recycling from the heat shield since it was found that the majority of the recycling flux occurs on two well-localized areas. [ABSTRACT FROM AUTHOR]

Published
2021
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31. Neural network surrogates of Bayesian diagnostic models for fast inference of plasma parameters.

Author

Pavone, A., Svensson, J., Krychowiak, M., Hergenhahn, U., Winters, V., Kornejew, P., Kwak, S., Hoefel, U., Koenig, R., and Wolf, R. C.

Subjects
ARTIFICIAL neural networks, NUCLEAR fusion, DISTRIBUTION (Probability theory), PLASMA flow
Abstract

We present a framework for training artificial neural networks (ANNs) as surrogate Bayesian models for the inference of plasma parameters from diagnostic data collected at nuclear fusion experiments, with the purpose of providing a fast approximation of conventional Bayesian inference. Because of the complexity of the models involved, conventional Bayesian inference can require tens of minutes for analyzing one single measurement, while hundreds of thousands can be collected during a single plasma discharge. The ANN surrogates can reduce the analysis time down to tens/hundreds of microseconds per single measurement. The core idea is to generate the training data by sampling them from the joint probability distribution of the parameters and observations of the original Bayesian model. The network can be trained to learn the reconstruction of plasma parameters from observations and the model joint probability distribution from plasma parameters and observations. Previous work has validated the application of such a framework to the former case at the Wendelstein 7-X and Joint European Torus experiments. Here, we first give a description of the general methodological principles allowing us to generate the training data, and then we show an example application of the reconstruction of the joint probability distribution of an effective ion charge Zeff-bremsstrahlung model from data collected at the latest W7-X experimental campaign. One key feature of such an approach is that the network is trained exclusively on data generated with the Bayesian model, requiring no experimental data. This allows us to replicate the training scheme and generate fast, surrogate ANNs for any validated Bayesian diagnostic model. [ABSTRACT FROM AUTHOR]

Published
2021
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32. Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000

Author

Pedersen T. S., Otte M., Lazerson S., Helander P., Bozhenkov S., Biedermann C., Klinger T., Wolf R. C., Bosch H. -S., Abramovic I., Akaslompolo S., Aleynikov P., Aleynikova K., Ali A., Alonso A., Anda G., Andreeva T., Ascasibar E., Baldzuhn J., Banduch M., Barbui T., Beidler C., Benndorf A., Beurskens M., Biel W., Birus D., Blackwell B., Blanco E., Blatzheim M., Bluhm T., Bockenhoff D., Bolgert P., Borchardt M., Bottger L. -G., Brakel R., Brandt C., Brauer T., Braune H., Burhenn R., Buttenschon B., Bykov V., Calvo I., Cappa A., Carls A., De Carvalho B. B., Castejon F., Cianciosa M., Cole M., Costea S., Cseh G., Czarnecka A., Dal Molin A., De La Cal E., De La Pena A., Degenkolbe S., Dhard C. P., Dinklage A., Dostal M., Drevlak M., Drewelow P., Drews P., Dudek A., Durodie F., Dzikowicka A., Von Eeten P., Effenberg F., Endler M., Erckmann V., Estrada T., Fahrenkamp N., Fellinger J., Feng Y., Figacz W., Ford O., Fornal T., Frerichs H., Fuchert G., Garcia-Munoz M., Geiger B., Geiger J., Gierse N., Gogoleva A., Goncalves B., Gradic D., Grahl M., Gross S., Grote H., Grulke O., Guerard C., Haas M., Harris J., Hartfuss H. -J., Hartmann D., Hathiramani D., Hein B., Heirnich S., Henneberg S., Hennig C., Hernandez J., Hidalgo C., Hidalgo U., Hirsch M., Hofel U., Holbe H., Holting A., Houry M., Huber V., Ionita C., Israeli B., Jablonski S., Jakubowski M., Van Vuuren A. J., Jenzsch H., Kaczmarczyk J., Kallmeyer J. -P., Kamionka U., Kasahara H., Kenmochi N., Kernbichler W., Killer C., Kinna D., Kleiber R., Knauer J., Kochl F., Kocsis G., Kolesnichenko Y., Konies A., Konig R., Kornejew P., Koster F., Kramer-Flecken A., Krampitz R., Krawzyk N., Kremeyer T., Krychowiak M., Ksiazek I., Kubkowska M., Kuhner G., Kurki-Suonio T., Kurz P., Kuttler K., Kwak S., Landreman M., Langenberg A., Lapayese F., Laqua H., Laqua H. -P., Laube R., Laux M., Lentz H., Lewerentz M., Liang Y., Liu S., Lobsien J. -F., Cisquella J. L., Lopez-Bruna D., Lore J., Lorenz A., Lui S., Lutsenko V., Maassberg H., Maisano-Brown J., Marchuk O., Marrelli L., Marsen S., Marushchenko N., Masuzaki S., McCarthy K., McNeely P., Medina F., Milojevic D., Mishchenko A., Missal B., Mittelstaedt J., Mollen A., Moncada V., Monnich T., Moseev D., Nagel M., Naujoks D., Neilson G. H., Neubauer O., Neuner U., Ngo T. -T., Niemann H., Nuhrenberg C., Nuhrenberg J., Ochando M., Ogawa K., Ongena J., Oosterbeek H., Pablant N., Pacella D., Pacios L., Panadero N., Pasch E., Pastor I., Pavone A., Pawelec E., Pedrosa A., Perseo V., Peterson B., Pilopp D., Pisano F., Piulatti M. E., Plunk G., Preynas M., Proll J., Sitjes A. P., Purps F., Rack M., Rahbarnia K., Riemann J., Risse K., Rong P., Rosenberger J., Rudischhauser L., Rummel K., Rummel T., Runov A., Rust N., Ryc L., Saitoh H., Satake S., Schacht J., Schmitz O., Schmuck S., Schneider B., Schneider M., Schneider W., Schrittwieser R., Schroder M., Schroder T., Schroder R., Schumacher H. W., Schweer B., Seki R., Sinha P., Sipilae S., Slaby C., Smith H., Sousa J., Spring A., Standley B., Stange T., Von Stechow A., Stephey L., Stoneking M., Stridde U., Suzuki Y., Svensson J., Szabolics T., Szepesi T., Thomsen H., Travere J. -M., Traverso P., Mora H. T., Tsuchiya H., Tsuijmura T., Turkin Y., Valet S., Van Milligen B., Vela L., Velasco J. -L., Vergote M., Vervier M., Viebke H., Vilbrandt R., Von Thun C. P., Wagner F., Wang E., Wang N., Warmer F., Wauters T., Wegener L., Wegner T., Weir G., Wendorf J., Wenzel U., Werner A., Wie Y., Wiegel B., Wilde F., Windisch T., Winkler M., Winters V., Wright A., Wurden G., Xanthopoulos P., Yamada I., Yasuhara R., Yokoyama M., Zhang D., Zilker M., Zimbal A., Zocco A., Zoletnik S., W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society, Massachusetts Institute of Technology. Department of Physics, Maisano-Brown, Jeannette D., Science and Technology of Nuclear Fusion, Pedersen, T, Otte, M, Lazerson, S, Helander, P, Bozhenkov, S, Biedermann, C, Klinger, T, Wolf, R, Bosch, H, Abramovic, I, Akaslompolo, S, Aleynikov, P, Aleynikova, K, Ali, A, Alonso, A, Anda, G, Andreeva, T, Ascasibar, E, Baldzuhn, J, Banduch, M, Barbui, T, Beidler, C, Benndorf, A, Beurskens, M, Biel, W, Birus, D, Blackwell, B, Blanco, E, Blatzheim, M, Bluhm, T, Bockenhoff, D, Bolgert, P, Borchardt, M, Bottger, L, Brakel, R, Brandt, C, Brauer, T, Braune, H, Burhenn, R, Buttenschon, B, Bykov, V, Calvo, I, Cappa, A, Carls, A, De Carvalho, B, Castejon, F, Cianciosa, M, Cole, M, Costea, S, Cseh, G, Czarnecka, A, Dal Molin, A, De La Cal, E, De La Pena, A, Degenkolbe, S, Dhard, C, Dinklage, A, Dostal, M, Drevlak, M, Drewelow, P, Drews, P, Dudek, A, Durodie, F, Dzikowicka, A, Von Eeten, P, Effenberg, F, Endler, M, Erckmann, V, Estrada, T, Fahrenkamp, N, Fellinger, J, Feng, Y, Figacz, W, Ford, O, Fornal, T, Frerichs, H, Fuchert, G, Garcia-Munoz, M, Geiger, B, Geiger, J, Gierse, N, Gogoleva, A, Goncalves, B, Gradic, D, Grahl, M, Gross, S, Grote, H, Grulke, O, Guerard, C, Haas, M, Harris, J, Hartfuss, H, Hartmann, D, Hathiramani, D, Hein, B, Heirnich, S, Henneberg, S, Hennig, C, Hernandez, J, Hidalgo, C, Hidalgo, U, Hirsch, M, Hofel, U, Holbe, H, Holting, A, Houry, M, Huber, V, Ionita, C, Israeli, B, Jablonski, S, Jakubowski, M, Van Vuuren, A, Jenzsch, H, Kaczmarczyk, J, Kallmeyer, J, Kamionka, U, Kasahara, H, Kenmochi, N, Kernbichler, W, Killer, C, Kinna, D, Kleiber, R, Knauer, J, Kochl, F, Kocsis, G, Kolesnichenko, Y, Konies, A, Konig, R, Kornejew, P, Koster, F, Kramer-Flecken, A, Krampitz, R, Krawzyk, N, Kremeyer, T, Krychowiak, M, Ksiazek, I, Kubkowska, M, Kuhner, G, Kurki-Suonio, T, Kurz, P, Kuttler, K, Kwak, S, Landreman, M, Langenberg, A, Lapayese, F, Laqua, H, Laube, R, Laux, M, Lentz, H, Lewerentz, M, Liang, Y, Liu, S, Lobsien, J, Cisquella, J, Lopez-Bruna, D, Lore, J, Lorenz, A, Lui, S, Lutsenko, V, Maassberg, H, Maisano-Brown, J, Marchuk, O, Marrelli, L, Marsen, S, Marushchenko, N, Masuzaki, S, Mccarthy, K, Mcneely, P, Medina, F, Milojevic, D, Mishchenko, A, Missal, B, Mittelstaedt, J, Mollen, A, Moncada, V, Monnich, T, Moseev, D, Nagel, M, Naujoks, D, Neilson, G, Neubauer, O, Neuner, U, Ngo, T, Niemann, H, Nuhrenberg, C, Nuhrenberg, J, Ochando, M, Ogawa, K, Ongena, J, Oosterbeek, H, Pablant, N, Pacella, D, Pacios, L, Panadero, N, Pasch, E, Pastor, I, Pavone, A, Pawelec, E, Pedrosa, A, Perseo, V, Peterson, B, Pilopp, D, Pisano, F, Piulatti, M, Plunk, G, Preynas, M, Proll, J, Sitjes, A, Purps, F, Rack, M, Rahbarnia, K, Riemann, J, Risse, K, Rong, P, Rosenberger, J, Rudischhauser, L, Rummel, K, Rummel, T, Runov, A, Rust, N, Ryc, L, Saitoh, H, Satake, S, Schacht, J, Schmitz, O, Schmuck, S, Schneider, B, Schneider, M, Schneider, W, Schrittwieser, R, Schroder, M, Schroder, T, Schroder, R, Schumacher, H, Schweer, B, Seki, R, Sinha, P, Sipilae, S, Slaby, C, Smith, H, Sousa, J, Spring, A, Standley, B, Stange, T, Von Stechow, A, Stephey, L, Stoneking, M, Stridde, U, Suzuki, Y, Svensson, J, Szabolics, T, Szepesi, T, Thomsen, H, Travere, J, Traverso, P, Mora, H, Tsuchiya, H, Tsuijmura, T, Turkin, Y, Valet, S, Van Milligen, B, Vela, L, Velasco, J, Vergote, M, Vervier, M, Viebke, H, Vilbrandt, R, Von Thun, C, Wagner, F, Wang, E, Wang, N, Warmer, F, Wauters, T, Wegener, L, Wegner, T, Weir, G, Wendorf, J, Wenzel, U, Werner, A, Wie, Y, Wiegel, B, Wilde, F, Windisch, T, Winkler, M, Winters, V, Wright, A, Wurden, G, Xanthopoulos, P, Yamada, I, Yasuhara, R, Yokoyama, M, Zhang, D, Zilker, M, Zimbal, A, Zocco, A, Zoletnik, S, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Department of Applied Physics, Aalto-yliopisto, Aalto University, and Pacella, D.

Subjects
Tokamak, Plasma parameters, Science, General Physics and Astronomy, Topology (electrical circuits), Topology, 7. Clean energy, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, 010305 fluids & plasmas, law.invention, law, 0103 physical sciences, 010306 general physics, Physics, Fusion, Wendelstein7-X, Stellarator, Multidisciplinary, ta114, General Chemistry, Plasma, Fusion power, Magnetic field, Erratum, Wendelstein 7-X, Stellarator
Abstract

Fusion energy research has in the past 40 years focused primarily on the tokamak concept, but recent advances in plasma theory and computational power have led to renewed interest in stellarators. The largest and most sophisticated stellarator in the world, Wendelstein 7-X (W7-X), has just started operation, with the aim to show that the earlier weaknesses of this concept have been addressed successfully, and that the intrinsic advantages of the concept persist, also at plasma parameters approaching those of a future fusion power plant. Here we show the first physics results, obtained before plasma operation: that the carefully tailored topology of nested magnetic surfaces needed for good confinement is realized, and that the measured deviations are smaller than one part in 100,000. This is a significant step forward in stellarator research, since it shows that the complicated and delicate magnetic topology can be created and verified with the required accuracy., Early stellarator designs suffered from high particle losses, an issue that can be addressed by optimization of the coils. Here the authors measure the magnetic field lines in the Wendelstein 7-X stellarator, confirming that the complicated design of the superconducting coils has been realized successfully.

Published
2016

33. Preparation, analysis, and application of coated glass targets for the Wendelstein 7-X laser blow-off system.

Author

Wegner, Th., Geiger, B., Foest, R., Jansen van Vuuren, A., Winters, V. R., Biedermann, C., Burhenn, R., Buttenschön, B., Cseh, G., Joda, I., Kocsis, G., Kunkel, F., Quade, A., Schäfer, J., Schmitz, O., and Szepesi, T.

Subjects
PHYSICAL vapor deposition, METAL coating, CERAMIC metals, CERAMIC coating, THICK films, PLASMA devices
Abstract

Coated glass targets are a key component of the Wendelstein 7-X laser blow-off system that is used for impurity transport studies. The preparation and analysis of these glass targets as well as their performance is examined in this paper. The glass targets have a high laser damage threshold and are coated via physical vapor deposition with µm thick films. In addition, nm-thin layers of Ti are used as an interface layer for improved ablation efficiency and reduced coating stress. Hence, the metallic or ceramic coating has a lateral homogeneity within 2% and contaminants less than 5%, being optimal for laser ablation processing. With this method, a short (few ms) and well defined pulse of impurities with about 1017 particles can be injected close to the last closed flux surface of Wendelstein 7-X. In particular, a significant amount of atoms with a velocity of about 1 km/s enters the plasma within 1 ms. The atoms are followed by a negligible concentration of slower clusters and macro-particles. This qualifies the use of the targets and applied laser settings for impurity transport studies with the laser blow-off system in Wendelstein 7-X. [ABSTRACT FROM AUTHOR]

Published
2020
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35. First results from the implementation of the ITER diagnostic residual gas analyzer prototype at Wendelstein 7-X.

Author

Schlisio, G., Klepper, C. C., Harris, J. H., Biewer, T. M., Winters, V. R., Wenzel, U., Kornejew, P., Laqua, H., and Krychowiak, M.

Subjects
MAGNETIC field effects, FUEL cycle, FUSION reactors, GAS fields, PARTIAL pressure, WASTE gases
Abstract

Fusion reactors and long pulse fusion experiments heavily depend on a continuous fuel cycle, which requires detailed monitoring of exhaust gases. We have used a diagnostic residual gas analyzer (DRGA) built as a prototype for ITER and integrated it on the most advanced stellarator fusion experiment, Wendelstein 7-X (W7-X). The DRGA was equipped with a sampling tube and assessed for gas time of flight sample response, effects of magnetic field on gas detection and practical aspects of use in a state of the art fusion environment. The setup was successfully commissioned and operated and was used to observe the gas composition of W7-X exhaust gases. The measured time of flight gas response was found to be in the order of a second for a 7 m sample tube. High values of magnetic field were found to affect the partial pressure readings of the DRGA and suggest that additional shielding is necessary in future experimental campaigns. [ABSTRACT FROM AUTHOR]

Published
2019
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42. EMC3-EIRENE simulation of first wall recycling fluxes in W7-X with relation to H-alpha measurements

Author

Winters, V R, Reimold, F, König, R, Krychowiak, M, Romba, T, Biedermann, C, Bozhenkov, S, Drewelow, P, Endler, M, Feng, Y, Frerichs, H, Fuchert, G, Geiger, J, Gao, Y, Harris, J H, Jakubowski, M, Kornejew, P, Kremeyer, T, Niemann, H, Pasch, E, Puig-Sitjes, A, Schlisio, G, Scott, E R, Wurden, G A, Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, and Weggen, Jörg

Subjects
7. Clean energy
Abstract

In the Wendelstein 7-X stellarator, the main locations of particle sources are expected to be the carbon divertors, baffles and graphite heat shield first wall. In this paper, the heat shield is implemented in EMC3-EIRENE to understand the expected areas and magnitudes of the recycling flux to this component. It is found that in the simulation the heat shield is not a significant source of recycling neutrals. The areas of simulated recycling flux are shown to correlate well with footprints of plasma-wetting seen in post-experimental campaign in-vessel inspection photos. EMC3-EIRENE reconstruction of line-integrated H-alpha measurements at the heat shield indicate that the majority of emission does not come from local recycling neutrals. Rather, the H-alpha signals at the heat shield are dominated by ionization of neutrals which have leaked from the divertor/baffle region into the midplane. The magnitude of the H-alpha line emission from the synthetic reconstruction is consistent with the experiment, indicating that a large overestimation of heat shield recycling would occur if these measurements were assumed to be from local recycling sources. In the future, it may be possible to obtain some information of local recycling from the heat shield since it was found that the majority of the recycling flux occurs on two well-localized areas.

43. Impurity sources and fluxes in W7-X: from the plasma-facing components to the edge layer

Author

W7-X Team, Wang, E., Brezinsek, S., Sereda, S., Buttenschön, B., Barbui, T., Dhard, C. P., Endler, M., Ford, O., Flom, E., Hammond, K. C., Jakubowski, M., Krychowiak, M., Kornejew, P., König, R., Liang, Y., Mayer, M., Naujoks, D., Neubauer, O., Oelmann, J., Rasinski, M., Winters, V. R., Goriaev, A., Wauters, T., Wei, Y., Zhang, D., Baumann, Klaus, Gantenbein, Gerd, Huber, Martina, Illy, Stefan, Jelonnek, John, Kobarg, Thorsten, Lang, Rouven, Leonhardt, Wolfgang, Mellein, Daniel, Papenfuß, Daniel, Scherer, Theo, Thumm, Manfred, Wadle, Simone, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society

Subjects
Technology, Materials science, Hydrogen, Proton, Divertor, Analytical chemistry, chemistry.chemical_element, Order (ring theory), Condensed Matter Physics, 7. Clean energy, 01 natural sciences, Atomic and Molecular Physics, and Optics, 010305 fluids & plasmas, chemistry, Impurity, Sputtering, 0103 physical sciences, ddc:530, 010306 general physics, ddc:600, Mathematical Physics, Helium, Order of magnitude
Abstract

Wendelstein 7-X (W7-X) is a nearly full-carbon machine with graphite divertors, baffles and shields in Operation Phase 1.2b (OP 1.2b). Divertor spectrometer measurements showed that an amount of helium and oxygen impurities existed in the predominately hydrogen plasma, which resulted in a high carbon impurity level by enhanced physical and chemical sputtering by these impurities in comparison with the pure impinging proton yields. In order to improve the wall conditions, especially to reduce the oxygen content, boronizations were applied in OP1.2b. After the boronization, an oxygen decrease by more than an order of magnitude was observed. Helium disappeared in comparison with OP1.2a due to reduced application of helium wall conditioning after introduction of boronizations. The overall radiation normalized to line integrated density was reduced by a factor of six. In addition, local CH4 injection was applied in the divertor in order to quantify the chemical sputtering by hydrogen on divertor plates. The experimentally determined effective D/XB of the A–X band of CH resulting from CH4 was ${\left[\tfrac{{D}}{{X}{B}}\right]}_{{{A}}^{2}{\rm{\Delta }}\to {{X}}^{2}{\rm{\Pi }}}^{{\rm{C}}{{\rm{H}}}_{4}\to {\rm{C}}{\rm{H}}}=16$ at T e ≈ 20 eV and n e ≈ 5 × 1018 m−3. It was applied to determine the hydrocarbon fluxes and further to deduce the particle flux ratio ГCH4/ГH on divertor plates.

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46. Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X

Author

Thomas Sunn Pedersen, I. Abramovic, P. Agostinetti, M. Agredano Torres, S. Äkäslompolo, J. Alcuson Belloso, P. Aleynikov, K. Aleynikova, M. Alhashimi, A. Ali, N. Allen, A. Alonso, G. Anda, T. Andreeva, C. Angioni, A. Arkhipov, A. Arnold, W. Asad, E. Ascasibar, M.-H. Aumeunier, K. Avramidis, E. Aymerich, S.-G. Baek, J. Bähner, A. Baillod, M. Balden, J. Baldzuhn, S. Ballinger, M. Banduch, S. Bannmann, A. Banon Navarro, A. Bañón Navarro, T. Barbui, C. Beidler, C. Belafdil, A. Bencze, A. Benndorf, M. Beurskens, C. Biedermann, O. Biletskyi, B. Blackwell, M. Blatzheim, T. Bluhm, D. Böckenhoff, G. Bongiovi, M. Borchardt, D. Borodin, J. Boscary, H. Bosch, T. Bosmann, B. Böswirth, L. Böttger, A. Bottino, S. Bozhenkov, R. Brakel, C. Brandt, T. Bräuer, H. Braune, S. Brezinsek, K. Brunner, S. Buller, R. Burhenn, R. Bussiahn, B. Buttenschön, A. Buzás, V. Bykov, I. Calvo, K. Camacho Mata, I. Caminal, B. Cannas, A. Cappa, A. Carls, F. Carovani, M. Carr, D. Carralero, B. Carvalho, J. Casas, D. Castano-Bardawil, F. Castejon, N. Chaudhary, I. Chelis, A. Chomiczewska, J.W. Coenen, M. Cole, F. Cordella, Y. Corre, K. Crombe, G. Cseh, B. Csillag, H. Damm, C. Day, M. de Baar, E. De la Cal, S. Degenkolbe, A. Demby, S. Denk, C. Dhard, A. Di Siena, A. Dinklage, T. Dittmar, M. Dreval, M. Drevlak, P. Drewelow, P. Drews, D. Dunai, E. Edlund, F. Effenberg, G. Ehrke, M. Endler, D.A. Ennis, F.J. Escoto, T. Estrada, E. Fable, N. Fahrenkamp, A. Fanni, J. Faustin, J. Fellinger, Y. Feng, W. Figacz, E. Flom, O. Ford, T. Fornal, H. Frerichs, S. Freundt, G. Fuchert, M. Fukuyama, F. Füllenbach, G. Gantenbein, Y. Gao, K. Garcia, J.M. García Regaña, I. García-Cortés, J. Gaspar, D.A. Gates, J. Geiger, B. Geiger, L. Giudicotti, A. González, A. Goriaev, D. Gradic, M. Grahl, J.P. Graves, J. Green, E. Grelier, H. Greuner, S. Groß, H. Grote, M. Groth, M. Gruca, O. Grulke, M. Grün, J. Guerrero Arnaiz, S. Günter, V. Haak, M. Haas, P. Hacker, A. Hakola, A. Hallenbert, K. Hammond, X. Han, S.K. Hansen, J.H. Harris, H. Hartfuß, D. Hartmann, D. Hathiramani, R. Hatzky, J. Hawke, S. Hegedus, B. Hein, B. Heinemann, P. Helander, S. Henneberg, U. Hergenhahn, C. Hidalgo, F. Hindenlang, M. Hirsch, U. Höfel, K.P. Hollfeld, A. Holtz, D. Hopf, D. Höschen, M. Houry, J. Howard, X. Huang, M. Hubeny, S. Hudson, K. Ida, Y. Igitkhanov, V. Igochine, S. Illy, C. Ionita-Schrittwieser, M. Isobe, M. Jabłczyńska, S. Jablonski, B. Jagielski, M. Jakubowski, A. Jansen van Vuuren, J. Jelonnek, F. Jenko, T. Jensen, H. Jenzsch, P. Junghanns, J. Kaczmarczyk, J. Kallmeyer, U. Kamionka, M. Kandler, S. Kasilov, Y. Kazakov, D. Kennedy, A. Kharwandikar, M. Khokhlov, C. Kiefer, C. Killer, A. Kirschner, R. Kleiber, T. Klinger, S. Klose, J. Knauer, A. Knieps, F. Köchl, G. Kocsis, Ya.I. Kolesnichenko, A. Könies, R. König, J. Kontula, P. Kornejew, J. Koschinsky, M.M. Kozulia, A. Krämer-Flecken, R. Krampitz, M. Krause, N. Krawczyk, T. Kremeyer, L. Krier, D.M. Kriete, M. Krychowiak, I. Ksiazek, M. Kubkowska, M. Kuczynski, G. Kühner, A. Kumar, T. Kurki-Suonio, S. Kwak, M. Landreman, P.T. Lang, A. Langenberg, H.P. Laqua, H. Laqua, R. Laube, S. Lazerson, M. Lewerentz, C. Li, Y. Liang, Ch. Linsmeier, J. Lion, A. Litnovsky, S. Liu, J. Lobsien, J. Loizu, J. Lore, A. Lorenz, U. Losada, F. Louche, R. Lunsford, V. Lutsenko, M. Machielsen, F. Mackel, J. Maisano-Brown, O. Maj, D. Makowski, G. Manduchi, E. Maragkoudakis, O. Marchuk, S. Marsen, E. Martines, J. Martinez-Fernandez, M. Marushchenko, S. Masuzaki, D. Maurer, M. Mayer, K.J. McCarthy, O. Mccormack, P. McNeely, H. Meister, B. Mendelevitch, S. Mendes, A. Merlo, A. Messian, A. Mielczarek, O. Mishchenko, B. Missal, R. Mitteau, V.E. Moiseenko, A. Mollen, V. Moncada, T. Mönnich, T. Morisaki, D. Moseev, G. Motojima, S. Mulas, M. Mulsow, M. Nagel, D. Naujoks, V. Naulin, T. Neelis, H. Neilson, R. Neu, O. Neubauer, U. Neuner, D. Nicolai, S.K. Nielsen, H. Niemann, T. Nishiza, T. Nishizawa, C. Nührenberg, R. Ochoukov, J. Oelmann, G. Offermanns, K. Ogawa, S. Okamura, J. Ölmanns, J. Ongena, J. Oosterbeek, M. Otte, N. Pablant, N. Panadero Alvarez, A. Pandey, E. Pasch, R. Pavlichenko, A. Pavone, E. Pawelec, G. Pechstein, G. Pelka, V. Perseo, B. Peterson, D. Pilopp, S. Pingel, F. Pisano, B. Plöckl, G. Plunk, P. Pölöskei, B. Pompe, A. Popov, M. Porkolab, J. Proll, M.J. Pueschel, M.-E. Puiatti, A. Puig Sitjes, F. Purps, K. Rahbarnia, M. Rasiński, J. Rasmussen, A. Reiman, F. Reimold, M. Reisner, D. Reiter, M. Richou, R. Riedl, J. Riemann, K. Riße, G. Roberg-Clark, V. Rohde, J. Romazanov, D. Rondeshagen, P. Rong, L. Rudischhauser, T. Rummel, K. Rummel, A. Runov, N. Rust, L. Ryc, P. Salembier, M. Salewski, E. Sanchez, S. Satake, G. Satheeswaran, J. Schacht, E. Scharff, F. Schauer, J. Schilling, G. Schlisio, K. Schmid, J. Schmitt, O. Schmitz, W. Schneider, M. Schneider, P. Schneider, R. Schrittwieser, T. Schröder, M. Schröder, R. Schroeder, B. Schweer, D. Schwörer, E. Scott, B. Shanahan, G. Sias, P. Sichta, M. Singer, P. Sinha, S. Sipliä, C. Slaby, M. Sleczka, H. Smith, J. Smoniewski, E. Sonnendrücker, M. Spolaore, A. Spring, R. Stadler, D. Stańczak, T. Stange, I. Stepanov, L. Stephey, J. Stober, U. Stroth, E. Strumberger, C. Suzuki, Y. Suzuki, J. Svensson, T. Szabolics, T. Szepesi, M. Szücs, F.L. Tabarés, N. Tamura, A. Tancetti, C. Tantos, J. Terry, H. Thienpondt, H. Thomsen, M. Thumm, J.M. Travere, P. Traverso, J. Tretter, E. Trier, H. Trimino Mora, T. Tsujimura, Y. Turkin, A. Tykhyi, B. Unterberg, P. van Eeten, B.Ph. van Milligen, M. van Schoor, L. Vano, S. Varoutis, M. Vecsei, L. Vela, J.L. Velasco, M. Vervier, N. Vianello, H. Viebke, R. Vilbrandt, G. Vogel, N. Vogt, C. Volkhausen, A. von Stechow, F. Wagner, E. Wang, H. Wang, F. Warmer, T. Wauters, L. Wegener, T. Wegner, G. Weir, U. Wenzel, A. White, F. Wilde, F. Wilms, T. Windisch, M. Winkler, A. Winter, V. Winters, R. Wolf, A.M. Wright, G.A. Wurden, P. Xanthopoulos, S. Xu, H. Yamada, H. Yamaguchi, M. Yokoyama, M. Yoshinuma, Q. Yu, M. Zamanov, M. Zanini, M. Zarnstorff, D. Zhang, S. Zhou, J. Zhu, C. Zhu, M. Zilker, A. Zocco, H. Zohm, S. Zoletnik, L. Zsuga, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. GPI - Grup de Processament d'Imatge i Vídeo, Universitat Politècnica de Catalunya. GREO - Grup de Recerca en Enginyeria Òptica, Pedersen, T, Abramovic, I, Agostinetti, P, Torres, M, Akaslompolo, S, Belloso, J, Aleynikov, P, Aleynikova, K, Alhashimi, M, Ali, A, Allen, N, Alonso, A, Anda, G, Andreeva, T, Angioni, C, Arkhipov, A, Arnold, A, Asad, W, Ascasibar, E, Aumeunier, M, Avramidis, K, Aymerich, E, Baek, S, Bahner, J, Baillod, A, Balden, M, Baldzuhn, J, Ballinger, S, Banduch, M, Bannmann, S, Navarro, A, Barbui, T, Beidler, C, Belafdil, C, Bencze, A, Benndorf, A, Beurskens, M, Biedermann, C, Biletskyi, O, Blackwell, B, Blatzheim, M, Bluhm, T, Bockenhoff, D, Bongiovi, G, Borchardt, M, Borodin, D, Boscary, J, Bosch, H, Bosmann, T, Boswirth, B, Bottger, L, Bottino, A, Bozhenkov, S, Brakel, R, Brandt, C, Brauer, T, Braune, H, Brezinsek, S, Brunner, K, Buller, S, Burhenn, R, Bussiahn, R, Buttenschon, B, Buzas, A, Bykov, V, Calvo, I, Mata, K, Caminal, I, Cannas, B, Cappa, A, Carls, A, Carovani, F, Carr, M, Carralero, D, Carvalho, B, Casas, J, Castano-Bardawil, D, Castejon, F, Chaudhary, N, Chelis, I, Chomiczewska, A, Coenen, J, Cole, M, Cordella, F, Corre, Y, Crombe, K, Cseh, G, Csillag, B, Damm, H, Day, C, de Baar, M, De la Cal, E, Degenkolbe, S, Demby, A, Denk, S, Dhard, C, Di Siena, A, Dinklage, A, Dittmar, T, Dreval, M, Drevlak, M, Drewelow, P, Drews, P, Dunai, D, Edlund, E, Effenberg, F, Ehrke, G, Endler, M, Ennis, D, Escoto, F, Estrada, T, Fable, E, Fahrenkamp, N, Fanni, A, Faustin, J, Fellinger, J, Feng, Y, Figacz, W, Flom, E, Ford, O, Fornal, T, Frerichs, H, Freundt, S, Fuchert, G, Fukuyama, M, Fullenbach, F, Gantenbein, G, Gao, Y, Garcia, K, Regana, J, Garcia-Cortes, I, Gaspar, J, Gates, D, Geiger, J, Geiger, B, Giudicotti, L, Gonzalez, A, Goriaev, A, Gradic, D, Grahl, M, Graves, J, Green, J, Grelier, E, Greuner, H, Gross, S, Grote, H, Groth, M, Gruca, M, Grulke, O, Grun, M, Arnaiz, J, Gunter, S, Haak, V, Haas, M, Hacker, P, Hakola, A, Hallenbert, A, Hammond, K, Han, X, Hansen, S, Harris, J, Hartfuss, H, Hartmann, D, Hathiramani, D, Hatzky, R, Hawke, J, Hegedus, S, Hein, B, Heinemann, B, Helander, P, Henneberg, S, Hergenhahn, U, Hidalgo, C, Hindenlang, F, Hirsch, M, Hofel, U, Hollfeld, K, Holtz, A, Hopf, D, Hoschen, D, Houry, M, Howard, J, Huang, X, Hubeny, M, Hudson, S, Ida, K, Igitkhanov, Y, Igochine, V, Illy, S, Ionita-Schrittwieser, C, Isobe, M, Jablczynska, M, Jablonski, S, Jagielski, B, Jakubowski, M, van Vuuren, A, Jelonnek, J, Jenko, F, Jensen, T, Jenzsch, H, Junghanns, P, Kaczmarczyk, J, Kallmeyer, J, Kamionka, U, Kandler, M, Kasilov, S, Kazakov, Y, Kennedy, D, Kharwandikar, A, Khokhlov, M, Kiefer, C, Killer, C, Kirschner, A, Kleiber, R, Klinger, T, Klose, S, Knauer, J, Knieps, A, Kochl, F, Kocsis, G, Kolesnichenko, Y, Konies, A, Konig, R, Kontula, J, Kornejew, P, Koschinsky, J, Kozulia, M, Kramer-Flecken, A, Krampitz, R, Krause, M, Krawczyk, N, Kremeyer, T, Krier, L, Kriete, D, Krychowiak, M, Ksiazek, I, Kubkowska, M, Kuczynski, M, Kuhner, G, Kumar, A, Kurki-Suonio, T, Kwak, S, Landreman, M, Lang, P, Langenberg, A, Laqua, H, Laube, R, Lazerson, S, Lewerentz, M, Li, C, Liang, Y, Linsmeier, C, Lion, J, Litnovsky, A, Liu, S, Lobsien, J, Loizu, J, Lore, J, Lorenz, A, Losada, U, Louche, F, Lunsford, R, Lutsenko, V, Machielsen, M, Mackel, F, Maisano-Brown, J, Maj, O, Makowski, D, Manduchi, G, Maragkoudakis, E, Marchuk, O, Marsen, S, Martines, E, Martinez-Fernandez, J, Marushchenko, M, Masuzaki, S, Maurer, D, Mayer, M, Mccarthy, K, Mccormack, O, Mcneely, P, Meister, H, Mendelevitch, B, Mendes, S, Merlo, A, Messian, A, Mielczarek, A, Mishchenko, O, Missal, B, Mitteau, R, Moiseenko, V, Mollen, A, Moncada, V, Monnich, T, Morisaki, T, Moseev, D, Motojima, G, Mulas, S, Mulsow, M, Nagel, M, Naujoks, D, Naulin, V, Neelis, T, Neilson, H, Neu, R, Neubauer, O, Neuner, U, Nicolai, D, Nielsen, S, Niemann, H, Nishiza, T, Nishizawa, T, Nuhrenberg, C, Ochoukov, R, Oelmann, J, Offermanns, G, Ogawa, K, Okamura, S, Olmanns, J, Ongena, J, Oosterbeek, J, Otte, M, Pablant, N, Alvarez, N, Pandey, A, Pasch, E, Pavlichenko, R, Pavone, A, Pawelec, E, Pechstein, G, Pelka, G, Perseo, V, Peterson, B, Pilopp, D, Pingel, S, Pisano, F, Plockl, B, Plunk, G, Poloskei, P, Pompe, B, Popov, A, Porkolab, M, Proll, J, Pueschel, M, Puiatti, M, Sitjes, A, Purps, F, Rahbarnia, K, Rasinski, M, Rasmussen, J, Reiman, A, Reimold, F, Reisner, M, Reiter, D, Richou, M, Riedl, R, Riemann, J, Risse, K, Roberg-Clark, G, Rohde, V, Romazanov, J, Rondeshagen, D, Rong, P, Rudischhauser, L, Rummel, T, Rummel, K, Runov, A, Rust, N, Ryc, L, Salembier, P, Salewski, M, Sanchez, E, Satake, S, Satheeswaran, G, Schacht, J, Scharff, E, Schauer, F, Schilling, J, Schlisio, G, Schmid, K, Schmitt, J, Schmitz, O, Schneider, W, Schneider, M, Schneider, P, Schrittwieser, R, Schroder, T, Schroder, M, Schroeder, R, Schweer, B, Schworer, D, Scott, E, Shanahan, B, Sias, G, Sichta, P, Singer, M, Sinha, P, Siplia, S, Slaby, C, Sleczka, M, Smith, H, Smoniewski, J, Sonnendrucker, E, Spolaore, M, Spring, A, Stadler, R, Stanczak, D, Stange, T, Stepanov, I, Stephey, L, Stober, J, Stroth, U, Strumberger, E, Suzuki, C, Suzuki, Y, Svensson, J, Szabolics, T, Szepesi, T, Szucs, M, Tabares, F, Tamura, N, Tancetti, A, Tantos, C, Terry, J, Thienpondt, H, Thomsen, H, Thumm, M, Travere, J, Traverso, P, Tretter, J, Trier, E, Mora, H, Tsujimura, T, Turkin, Y, Tykhyi, A, Unterberg, B, van Eeten, P, van Milligen, B, van Schoor, M, Vano, L, Varoutis, S, Vecsei, M, Vela, L, Velasco, J, Vervier, M, Vianello, N, Viebke, H, Vilbrandt, R, Vogel, G, Vogt, N, Volkhausen, C, von Stechow, A, Wagner, F, Wang, E, Wang, H, Warmer, F, Wauters, T, Wegener, L, Wegner, T, Weir, G, Wenzel, U, White, A, Wilde, F, Wilms, F, Windisch, T, Winkler, M, Winter, A, Winters, V, Wolf, R, Wright, A, Wurden, G, Xanthopoulos, P, Xu, S, Yamada, H, Yamaguchi, H, Yokoyama, M, Yoshinuma, M, Yu, Q, Zamanov, M, Zanini, M, Zarnstorff, M, Zhang, D, Zhou, S, Zhu, J, Zhu, C, Zilker, M, Zocco, A, Zohm, H, Zoletnik, S, Zsuga, L, Fusion and Plasma Physics, Department of Applied Physics, National Institute for Fusion Science, Aalto-yliopisto, Aalto University, Science and Technology of Nuclear Fusion, Group Heemels, Control Systems Technology, and Turbulence in Fusion Plasmas

Subjects
Magnetic confinement, Nuclear and High Energy Physics, Technology, Materials science, Detachment, Nuclear engineering, Física::Física de partícules [Àrees temàtiques de la UPC], Imatges -- Processament, stellarator, Divertor, Image processing, Physics::Plasma Physics, divertor, Wendelstein 7-X, ddc:530, FIS/03 - FISICA DELLA MATERIA, Neoclassical optimization, Stellarators, Reactors de fusió, magnetic confinement, Enginyeria de la telecomunicació::Processament del senyal::Processament de la imatge i del senyal vídeo [Àrees temàtiques de la UPC], Condensed Matter Physics, ddc, Fusion reactors, Physics and Astronomy, detachment, neoclassical optimization, ddc:620, ddc:600, Paper, FEC 2020 Summaries and Overviews
Abstract

We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens of seconds. Pellet fueling allows for plasma phases with reduced ion-temperature-gradient turbulence, and during such phases, the overall confinement is so good (energy confinement times often exceeding 200 ms) that the attained density and temperature profiles would not have been possible in less optimized devices, since they would have had neoclassical transport losses exceeding the heating applied in W7-X. This provides proof that the reduction of neoclassical transport through magnetic field optimization is successful. W7-X plasmas generally show good impurity screening and high plasma purity, but there is evidence of longer impurity confinement times during turbulence-suppressed phases. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under Grant Agreement No. 633053. Peer Reviewed Article signat per 497 autors/es: Thomas Sunn Pedersen1,2,∗ , I. Abramovic3, P. Agostinetti4, M. Agredano Torres1, S. Äkäslompolo1, J. Alcuson Belloso1, P. Aleynikov1, K. Aleynikova1, M. Alhashimi1, A. Ali1, N. Allen5, A. Alonso6, G. Anda7, T. Andreeva1, C. Angioni8, A. Arkhipov8, A. Arnold1, W. Asad8, E. Ascasibar6, M.-H. Aumeunier9, K. Avramidis10, E. Aymerich11, S.-G. Baek3, J. Bähner1, A. Baillod12, M. Balden1, M. Balden8, J. Baldzuhn1, S. Ballinger3, M. Banduch1, S. Bannmann1, A. Banon Navarro8, A. Bañon Navarro ´ 1, T. Barbui13, C. Beidler1, C. Belafdil9, A. Bencze7, A. Benndorf1, M. Beurskens1, C. Biedermann1, O. Biletskyi14, B. Blackwell15, M. Blatzheim1, T. Bluhm1, D. Böckenhoff1, G. Bongiovi16, M. Borchardt1, D. Borodin17, J. Boscary8, H. Bosch1,18, T. Bosmann19, B. Böswirth8, L. Böttger1, A. Bottino8, S. Bozhenkov1, R. Brakel1, C. Brandt1, T. Bräuer1, H. Braune1, S. Brezinsek17, K. Brunner1, S. Buller1, R. Burhenn1, R. Bussiahn1, B. Buttenschön1, A. Buzás7, V. Bykov1, I. Calvo6, K. Camacho Mata1, I. Caminal20, B. Cannas11, A. Cappa6, A. Carls1, F. Carovani1, M. Carr21, D. Carralero6, B. Carvalho22, J. Casas20, D. Castano-Bardawil17, F. Castejon6, N. Chaudhary1, I. Chelis23, A. Chomiczewska24, J.W. Coenen13,17, M. Cole1, F. Cordella25, Y. Corre9, K. Crombe26, G. Cseh7, B. Csillag7, H. Damm1, C. Day10, M. de Baar27, E. De la Cal6, S. Degenkolbe1, A. Demby13, S. Denk3, C. Dhard1, A. Di Siena8,28, A. Dinklage12, T. Dittmar17, M. Dreval14, M. Drevlak1, P. Drewelow1, P. Drews17, D. Dunai7, E. Edlund3, F. Effenberg29, G. Ehrke1, M. Endler1, D.A. Ennis5, F.J. Escoto6, T. Estrada6, E. Fable8, N. Fahrenkamp1, A. Fanni11, J. Faustin1, J. Fellinger1, Y. Feng1, W. Figacz4, E. Flom13, O. Ford1, T. Fornal24, H. Frerichs13, S. Freundt1, G. Fuchert1, M. Fukuyama30, F. Füllenbach1, G. Gantenbein10, Y. Gao1, K. Garcia13, J.M. García Regaña6, I. García-Cortés6, J. Gaspar31, D.A. Gates29, J. Geiger1, B. Geiger13, L. Giudicotti32, A. González6, A. Goriaev26,33, D. Gradic1, M. Grahl1, J.P. Graves12, J. Green13, E. Grelier9, H. Greuner8, S. Groß1, H. Grote1, M. Groth34, M. Gruca24, O. Grulke1,35, M. Grün1, J. Guerrero Arnaiz1, S. Günter8, V. Haak1, M. Haas1, P. Hacker1, A. Hakola36, A. Hallenbert1, K. Hammond29, X. Han17,37, S.K. Hansen3, J.H. Harris38, H. Hartfuß1, D. Hartmann1, D. Hathiramani1, R. Hatzky8, J. Hawke39, S. Hegedus7, B. Hein8, B. Heinemann8, P. Helander12, S. Henneberg1, U. Hergenhahn8,40, C. Hidalgo6, F. Hindenlang8, M. Hirsch1, U. Höfel1, K.P. Hollfeld17, A. Holtz1, D. Hopf8, D. Höschen17, M. Houry9, J. Howard19, X. Huang41, M. Hubeny17, S. Hudson29, K. Ida9, Y. Igitkhanov10, V. Igochine8, S. Illy10, C. Ionita-Schrittwieser42, M. Isobe39, M. Jabłczynska ´ 24, S. Jablonski24, B. Jagielski1, M. Jakubowski1, A. Jansen van Vuuren1, J. Jelonnek10, F. Jenko8, F. Jenko8, T. Jensen35, H. Jenzsch1, P. Junghanns8, J. Kaczmarczyk24, J. Kallmeyer1, U. Kamionka1, M. Kandler8, S. Kasilov43, Y. Kazakov26, D. Kennedy1, A. Kharwandikar1, M. Khokhlov1, C. Kiefer8, C. Killer1, A. Kirschner17, R. Kleiber1, T. Klinger12, S. Klose1, J. Knauer1, A. Knieps17, F. Köchl44, G. Kocsis7, Ya.I. Kolesnichenko45, A. Könies1, R. König1, J. Kontula34, P. Kornejew1, J. Koschinsky, M.M. Kozulia14, A. Krämer-Flecken17, R. Krampitz1, M. Krause1, N. Krawczyk24, T. Kremeyer1, L. Krier10, D.M. Kriete5, M. Krychowiak1, I. Ksiazek46, M. Kubkowska24, M. Kuczynski1, G. Kühner1, A. Kumar15, T. Kurki-Suonio34, S. Kwak1, M. Landreman47, P.T. Lang8, A. Langenberg1, H.P. Laqua12, H. Laqua1, R. Laube1, S. Lazerson1, M. Lewerentz1, C. Li17, Y. Liang17, Ch. Linsmeier17, J. Lion1, A. Litnovsky17,48, S. Liu37, J. Lobsien1, J. Loizu12, J. Lore38, A. Lorenz1, U. Losada6, F. Louche26, R. Lunsford29, V. Lutsenko45, M. Machielsen12, F. Mackel8, J. Maisano-Brown3, O. Maj8, D. Makowski49, G. Manduchi50, E. Maragkoudakis6, O. Marchuk17, S. Marsen1, E. Martines4, J. Martinez-Fernandez6, M. Marushchenko1, S. Masuzaki41, D. Maurer5, M. Mayer8, K.J. McCarthy6, O. Mccormack4, P. McNeely1, H. Meister8, B. Mendelevitch8, S. Mendes1, A. Merlo1, A. Messian26, A. Mielczarek49, O. Mishchenko1, B. Missal1, R. Mitteau9, V.E. Moiseenko14, A. Mollen1, V. Moncada9, T. Mönnich1, T. Morisaki41, D. Moseev1, G. Motojima41, S. Mulas6, M. Mulsow1, M. Nagel1, D. Naujoks1, V. Naulin35, T. Neelis19, H. Neilson29, R. Neu8, O. Neubauer17, U. Neuner1, D. Nicolai17, S.K. Nielsen35, H. Niemann1, T. Nishiza1, T. Nishizawa1, T. Nishizawa8, C. Nührenberg1, R. Ochoukov8, J. Oelmann17, G. Offermanns17 K. Ogawa41, S. Okamura41, J. Ölmanns17, J. Ongena26, J. Oosterbeek1, M. Otte1, N. Pablant29, N. Panadero Alvarez6, N. Panadero Alvarez6, A. Pandey1, E. Pasch1, R. Pavlichenko14, A. Pavone1, E. Pawelec46, G. Pechstein1, G. Pelka24, V. Perseo1, B. Peterson41, D. Pilopp1, S. Pingel1, F. Pisano11, B. Plöckl8, G. Plunk1, P. Pölöskei1, B. Pompe2, A. Popov51, M. Porkolab3, J. Proll19, M.J. Pueschel19,27, M.-E. Puiatti52, A. Puig Sitjes1, F. Purps1, K. Rahbarnia1, M. Rasinski ´ 17, J. Rasmussen35, A. Reiman29, F. Reimold1, M. Reisner8, D. Reiter17, M. Richou9, R. Riedl8, J. Riemann1, K. Riße1, G. Roberg-Clark1, V. Rohde8, J. Romazanov17, D. Rondeshagen1, P. Rong1, L. Rudischhauser1, T. Rummel1, K. Rummel1, A. Runov1, N. Rust1, L. Ryc24, P. Salembier20, M. Salewski35, E. Sanchez6, S. Satake41, G. Satheeswaran17, J. Schacht1, E. Scharff1, F. Schauer8, J. Schilling1, G. Schlisio1, K. Schmid8, J. Schmitt5, O. Schmitz13, W. Schneider1, M. Schneider1, P. Schneider8, R. Schrittwieser42, T. Schröder1, M. Schröder1, R. Schroeder1, B. Schweer26, D. Schwörer1, E. Scott1, E. Scott8, B. Shanahan1, G. Sias11, P. Sichta29, M. Singer1, P. Sinha29, S. Sipliä34, C. Slaby1, M. Sleczka53, H. Smith1, J. Smoniewski54, E. Sonnendrücker8, M. Spolaore4, A. Spring1, R. Stadler8, D. Stanczak24, T. Stange1, I. Stepanov26, L. Stephey13, J. Stober8, U. Stroth8,55, E. Strumberger8, C. Suzuki41, Y. Suzuki41, J. Svensson1, T. Szabolics7, T. Szepesi7, M. Szücs7, F.L. Tabares6, N. Tamura41, A. Tancetti35, C. Tantos10, J. Terry3, H. Thienpondt6, H. Thomsen1, M. Thumm10, J.M. Travere9, P. Traverso5, J. Tretter8, E. Trier8, H. Trimino Mora1, T. Tsujimura41, Y. Turkin1, A. Tykhyi45, B. Unterberg17, P. van Eeten1, B.Ph. van Milligen6, M. van Schoor26, L. Vano1, S. Varoutis10, M. Vecsei7, L. Vela56, J.L. Velasco6, M. Vervier17, N. Vianello50, H. Viebke1, R. Vilbrandt1, G. Vogel8, N. Vogt1, C. Volkhausen1, A. von Stechow1, F. Wagner1, E. Wang17, H. Wang57, F. Warmer1, T. Wauters26, L. Wegener1, T. Wegner1, G. Weir1, U. Wenzel1, A. White3, F. Wilde1, F. Wilms1, T. Windisch1, M. Winkler1, A. Winter1, V. Winters1, R. Wolf118, A.M. Wright29, G.A. Wurden39, P. Xanthopoulos1, S. Xu17, H. Yamada58, H. Yamaguchi41, M. Yokoyama41, M. Yoshinuma41, Q. Yu8, M. Zamanov14, M. Zanini1, M. Zarnstorff29, D. Zhang1, S. Zhou17, J. Zhu1, C. Zhu29, M. Zilker8, A. Zocco1, H. Zohm8, S. Zoletnik7 and L. Zsuga7 // 1 Max Planck Institute for Plasma Physics, Garching and Greifswald, Germany: 2 University of Greifswald, Greifswald, Germany; 3 Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States of America; 4 Consorzio RFX, Corso Stati Uniti, 4-35127 Padova, Italy; 5 Auburn University, Auburn, AL 36849, United States of America; 6 CIEMAT, Avenida Complutense, 40, 28040 Madrid, Spain; 7 Center for Energy Research, Konkoly-Thegeut 29-33, 1121 Budapest, Hungary; 8 Max-Planck-Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching bei München, Germany; 9 CEA Cadarache, 13115 Saint-Paul-lez-Durance, France; 10 Karlsruhe Institute of Technology, Kaiserstr. 12, 76131 Karlsruhe, Germany; 11 University of Cagliari, Via Universita, 40, 09124 Cagliari, Italy; 12 École Polytechnique Fédérale de Lausanne, Swiss Plasma Center, CH-1015 Lausanne, Switzerland; 13 University of Wisconsin–Madison, Engineering Drive, Madison, WI 53706, United States of America; 14 Institute of Plasma Physics, National Science Center ‘Kharkiv Institute of Physics and Technology’, Kharkiv, Ukraine; 15 The Australian National University, Acton ACT 2601, Canberra, Australia; 16 Department of Engineering, University of Palermo, Viale delle Scienze, Edificio 6, Palermo, 90128, Italy; 17 Forschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung—Plasmaphysik, 52425 Jülich, Germany; 18 Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany; 19 Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands; 20 Universitat Politècnica de Catalunya. BarcelonaTech, C. Jordi Girona, 31, 08034 Barcelona, Spain; 21 Culham Center for Fusion Energy, Abingdon OX14 3EB, United Kingdom; 22 Instituto de Plasmas e Fusao Nuclear, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; 23 Department of Physics, National and Kapodistrian University of Athens, 15784 Athens, Greece; 24 Institute of Plasma Physics and Laser Microfusion, 23 Hery Str., 01-497 Warsaw, Poland; 25 ENEA—Centro Ricerche Frascati, Via Enrico Fermi, 45, 00044 Frascati RM, Italy; 26 Laboratory for Plasma Physics, LPP-ERM/KMS, TEC Partner, B-1000 Brussels, Belgium; 27 Dutch Institute for Fundamental Energy Research, PO Box 6336, 5600 HH Eindhoven, Netherlands; 28 University of Texas, Austin, TX, United States of America; 29 Princeton Plasma Physics Laboratory, Princeton, NJ 08543, United States of America; 30 Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan; 31 Aix-Marseille University, Jardin du Pharo, 58 Boulevard Charles Livon, 13007, Marseille, France; 32 Department of Physics and Astronomy, Padova University, Via Marzolo 8, 35131 Padova, Italy; 33 Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Ghent, Belgium; 34 Aalto University, 02150 Espoo, Finland; 35 Department of Physics, Technical University of Denmark, Anker Engelunds Vej, 2800 Kgs Lyngby, Denmark; 36 VTT Technical Research Center of Finland Ltd., PO Box 1000, FI-02044 VTT, Finland; 37 Institute of Plasma Physics, Chinese Academy of Sciences, 230031 Hefei, Anhui, China; 38 Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, United States of America; 39 Los Alamos National Laboratory, NM 87545, United States of America; 40 Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany; 41 National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi-cho, Toki, Gifu Prefecture 509-5292, Japan; 42 Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria; 43 Graz University of Technology, Rechbauerstraße 12, 8010 GRAZ, Austria; 44 Austrian Academy of Science, Doktor-Ignaz-Seipel-Platz 2, 1010 Wien, Austria; 45 Institute for Nuclear Research, prospekt Nauky 47, Kyiv 03028, Ukraine; 46 University of Opole, plac Kopernika 11a, 45-001 Opole, Poland; 47 University of Maryland, Paint Branch Drive, College Park, MA 20742, United States of America; 48 National Research Nuclear University MEPhI, 115409 Moscow, Russian Federation; 49 Department of Microelectronics and Computer Science, Lodz University of Technology, Wolczanska 221/223, 90-924 Lodz, Poland; 50 Consiglio Nazionale delle Ricerche, Piazzale Aldo Moro, 7, 00185 Roma, Italy; 51 Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26 Politekhnicheskaya, St Petersburg 194021, Russian Federation; 52 Istituto di Fisica del Plasma Piero Caldirola, Via Roberto Cozzi, 53, 20125 Milano, Italy; 53 University of Szczecin, 70-453, aleja Papieza Jana Pawła II 22A, Szczecin, Poland; 54 Lawrence University, 711 E Boldt Way, Appleton, WI 54911, United States of America; 55 Physik-Department E28, Technische Universität München, 85747 Garching, Germany; 56 Universidad Carlos III de Madrid, Av. de la Universidad, 30 Madrid, Spain; 57 Yale University, New Haven, CT 06520, United States of America; 58 University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chhiab 277-0882, Japan Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.a - Per a 2030, augmentar la cooperació internacional per tal de facilitar l’accés a la investigació i a les tecnolo­gies energètiques no contaminants, incloses les fonts d’energia renovables, l’eficiència energètica i les tecnologies de combustibles fòssils avançades i menys contaminants, i promoure la inversió en infraestructures energètiques i tecnologies d’energia no contaminant

Published
2022
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47. First Observation of a Stable Highly Dissipative Divertor Plasma Regime on the Wendelstein 7-X Stellarator.

Author

Zhang D, König R, Feng Y, Burhenn R, Brezinsek S, Jakubowski M, Buttenschön B, Niemann H, Pavone A, Krychowiak M, Kwak S, Svensson J, Gao Y, Pedersen TS, Alonso A, Baldzuhn J, Beidler CD, Biedermann C, Bozhenkov S, Brunner KJ, Damm H, Hirsch M, Giannone L, Drewelow P, Effenberg F, Fuchert G, Hammond KC, Höfel U, Killer C, Knauer J, Laqua HP, Laube R, Pablant N, Pasch E, Penzel F, Rahbarnia K, Reimold F, Thomsen H, Winters V, Wagner F, Klinger T, and W-X Team

Abstract

For the first time, the optimized stellarator Wendelstein 7-X has operated with an island divertor. An operation regime in hydrogen was found in which the total plasma radiation approached the absorbed heating power without noticeable loss of stored energy. The divertor thermography recorded simultaneously a strong reduction of the heat load on all divertor targets, indicating almost complete power detachment. This operation regime was stably sustained over several energy confinement times until the preprogrammed end of the discharge. The plasma radiation is mainly due to oxygen and is located at the plasma edge. This plasma scenario is reproducible and robust at various heating powers, plasma densities, and gas fueling locations. These experimental results show that the island divertor concept actually works and displays good power dissipation potential, producing a promising exhaust concept for the stellarator reactor line.

Published
2019
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48. The expansion and performance of national newborn screening programmes for cystic fibrosis in Europe.

Author

Barben J, Castellani C, Dankert-Roelse J, Gartner S, Kashirskaya N, Linnane B, Mayell S, Munck A, Sands D, Sommerburg O, Pybus S, Winters V, and Southern KW

Subjects
Cystic Fibrosis epidemiology, Cystic Fibrosis genetics, Cystic Fibrosis Transmembrane Conductance Regulator genetics, Europe epidemiology, Genetic Testing methods, Health Care Surveys, Humans, Infant, Newborn, National Health Programs standards, National Health Programs statistics & numerical data, Program Evaluation, Reference Standards, Cystic Fibrosis diagnosis, Neonatal Screening methods, Neonatal Screening standards
Abstract

Background: Newborn screening (NBS) for cystic fibrosis (CF) is a well-established public health strategy with international standards. The aim of this study was to provide an update on NBS for CF in Europe and assess performance against the standards., Methods: Questionnaires were sent to key workers in each European country., Results: In 2016, there were 17 national programmes, 4 countries with regional programmes and 25 countries not screening in Europe. All national programmes employed different protocols, with IRT-DNA the most common strategy. Five countries were not using DNA analysis. In addition, the processing and structure of programmes varied considerably. Most programmes were achieving the ECFS standards with respect to timeliness, but were less successful with respect to sensitivity and specificity., Conclusions: There has been a steady increase in national CF NBS programmes across Europe with variable strategies and outcomes that reflect the different approaches., (Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Published
2017
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49. Aneurysmal bone cyst of the zygomatic arch.

Author

Winters V, Schraepen T, Geusens E, Vanwijck R, and Broeckx J

Subjects
Adult, Bone Cysts, Aneurysmal diagnostic imaging, Contrast Media, Gadolinium, Humans, Magnetic Resonance Imaging, Male, Maxillary Diseases diagnosis, Maxillary Diseases diagnostic imaging, Tomography, X-Ray Computed, Ultrasonography, Zygoma diagnostic imaging, Bone Cysts, Aneurysmal diagnosis, Zygoma pathology
Abstract

We present a case of aneurysmal bone cyst in the jaw investigated with plain film, US, computed tomography (axial, precontrast) and magnetic resonance (1 Tesla, axial T1 weighted before and after Gadolinium administration, axial and coronal T2-weighted after Gadolinium administration). The zygomatic arch is a very rare location for an aneurysmal bone cyst: as far as we know, only a few cases are found in the literature.

Published
1998

50. Schwannoma of the trachea.

Author

Schraepen T, Winters V, Bijnens E, and Broeckx J

Subjects
Adult, Contrast Media, Dyspnea diagnosis, Gadolinium, Humans, Magnetic Resonance Imaging, Male, Neoplasm Invasiveness, Neurilemmoma diagnostic imaging, Neurilemmoma pathology, Respiratory Sounds diagnosis, Tomography, X-Ray Computed, Tracheal Neoplasms diagnostic imaging, Tracheal Neoplasms pathology, Neurilemmoma diagnosis, Tracheal Neoplasms diagnosis
Abstract

In this study we present a case of schwannoma of the trachea investigated with computer tomography (axial, precontrast) and magnetic resonance (1 Tesla, sagittal T1w before and after Gadolinium, sagittal T2w, coronal and axial after Gadolinium). The topographic abilities of MR allowed us to determine the exact location and extension of the tumor in the trachea. As far as we know, this study, based on magnetic resonance, is the first of the kind in the radiologic literature.

Published
1997

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