Author: "Baldzuhn, J." / Database: OpenAIRE - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Baldzuhn, J."' showing total 80 results

Start Over Author "Baldzuhn, J." Database OpenAIRE

80 results on '"Baldzuhn, J."'

1. Plasma flow measurements based on charge exchange recombination spectroscopy in the Wendelstein 7-X stellarator

Author: Alonso, J. A., Ford, O. P., Vanó, L., Äkäslompolo, S., Buller, S., McDermott, R., Smith, H. M., Baldzuhn, J., Beidler, C. D., Beurskens, M., Bozhenkov, S., Brunner, K. J., Calvo, I., Carralero, D., Dinklage, A., Estrada, T., Fuchert, G., Geiger, J., Knauer, J., Langenberg, A., Pablant, N. A., Pasch, E., Poloskei, P. Zs, Velasco, J. L., Windisch, T., 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, 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 initial operation of neutral beams in Wendelstein 7-X enabled the first measurements of carbon (C6+) temperature and rotation with a multi-chord charge exchange recombination spectroscopy system. In this article we analyse the velocity measurements obtained with this system to infer the profiles of radial electric field, E r, and net parallel velocity of fully stripped carbon ions, V ‖. We include a general treatment of the flow geometry and the velocity corrections due to the energy dependence of the charge exchange cross section. The inverted profiles are compared with neoclassical calculations for various plasma conditions and two magnetic configurations. It is found that both the E r and V ‖ experimental profiles agree in sign and order of magnitude with the neoclassical expectations and reproduce the expected dependencies on plasma parameters and magnetic configuration, within the reduced dataset presented. However, quantitative differences with respect to the neoclassical profiles are observed above the estimated errors in various conditions.
Published: 2022
Full Text: View/download PDF

2. 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
Full Text: View/download PDF

3. 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

4. High-performance ECRH at W7-X: experience and perspectives

Author: W7-X Team, Laqua, H. P., Baldzuhn, J., Braune, H., Bozhenkov, S., Brunner, K., Hirsch, M., Hoefel, U., Knauer, J., Langenberg, A., Marsen, S., Moseev, D., Pasch, E., Rahbarnia, K., Stange, T., Wolf, R. C., Pablant, N., Grulke, O., 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: Technology, ddc:600
Published: 2021

5. Suppression of core turbulence by profile shaping in Wendelstein 7-X

Author: Stechow, A. v., Grulke, O., Wegner, Th., Proll, J. H. E., Alcus��n, J. A., Smith, H. M., Baldzuhn, J., Beidler, C. D., Beurskens, M. N. A., Bozhenkov, S. A., Edlund, E., Geiger, B., Huang, Z., Ford, O. P., Fuchert, G., Langenberg, A., Pablant, N., Pasch, E., Porkolab, M., Rahbarnia, K., Schilling, J., Scott, E. R., Thomsen, H., Van��, L., Weir, G., and Team, The W7-X
Subjects: Plasma Physics (physics.plasm-ph), FOS: Physical sciences, Physics - Plasma Physics
Abstract: In the Wendelstein 7-X magnetic confinement experiment, a reduction of turbulent density fluctuations as well as anomalous impurity diffusion is associated with a peaking of the plasma density profile. These effects correlate with improved confinement and appear largely due to a reduction of anomalous transport as the change in neoclassical transport is small. The observed decrease of turbulent heat flux with increased density gradients is in agreement with nonlinear gyrokinetic simulations, and has been attributed to the unique geometry of W7-X that limits the severity of trapped electron modes.
Published: 2020

6. Charge exchange recombination spectroscopy at Wendelstein 7-X

Author: W7-X Team, Ford, O. P., Vanó, L., Alonso, J. A., Baldzuhn, J., Beurskens, M. N. A., Biedermann, C., Bozhenkov, S. A., Fuchert, G., Geiger, B., Hartmann, D., Jaspers, R. J. E., Kappatou, A., Langenberg, A., Lazerson, S. A., McDermott, R. M., McNeely, P., Neelis, T. W. C., Pablant, N. A., Pasch, E., Rust, N., Schroeder, R., Scott, E. R., Smith, H. M., Wegner, Th., Kunkel, F., 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, Applied Physics and Science Education, Science and Technology of Nuclear Fusion, Sensorics for fusion reactors, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Subjects: 010302 applied physics, Technology, Materials science, Plasma parameters, Plasma, 01 natural sciences, 010305 fluids & plasmas, Computational physics, law.invention, law, Electric field, 0103 physical sciences, Physics::Accelerator Physics, Emission spectrum, Wendelstein 7-X, Spectroscopy, ddc:600, Instrumentation, Stellarator, Beam (structure)
Abstract: The Charge Exchange Recombination Spectroscopy (CXRS) diagnostic has become a routine diagnostic on almost all major high temperature fusion experimental devices. For the optimized stellarator Wendelstein 7-X (W7-X), a highly flexible and extensive CXRS diagnostic has been built to provide high-resolution local measurements of several important plasma parameters using the recently commissioned neutral beam heating. This paper outlines the design specifics of the W7-X CXRS system and gives examples of the initial results obtained, including typical ion temperature profiles for several common heating scenarios, toroidal flow and radial electric field derived from velocity measurements, beam attenuation via beam emission spectra, and normalized impurity density profiles under some typical plasma conditions.
Published: 2020

7. 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
Full Text: View/download PDF

8. Inspection of W 7-X plasma-facing components after the operation phase OP1.2b: observations and first assessments

Author: W7-X Team, Dhard, C. P., Äkäslompolo, S., Balden, M., Baldzuhn, J., Biedermann, C., Bräuer, T., Brezinsek, S., Endler, M., Hayashi, Y., Hwangbo, D., Kajita, S., Krause, M., Kornejew, P., Masuzaki, S., Mayer, M., Motojima, G., Naujoks, D., Otte, M., Rohde, 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: Technology, Toroid, Materials science, Nuclear engineering, Divertor, Baffle, Plasma, Condensed Matter Physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, 010305 fluids & plasmas, law.invention, law, Shield, 0103 physical sciences, Deposition (phase transition), Head (vessel), ddc:530, 010306 general physics, ddc:600, Mathematical Physics, Stellarator
Abstract: Due to its twisted magnetic field configurations, the orientation of the plasma-facing components (PFCs) of the Wendelstein 7-X stellarator is changed from bean shape to triangular shape along the plasma axis within a module. The PFCs consist of graphite (test divertor units, baffles, head shield tiles, toroidal divertor closures) and stainless steel components (wall panels, pumping gap panels, poloidal closures). In order to document the status of these components as well as to get the first footprints of the plasma-wall interactions (PWI) that occurred during the plasma campaign, a detailed inspection of the whole plasma vessel after the plasma campaign is of vital importance. Such an inspection was carried out after the operation phase OP1.2b completed in October 2018. A number of observations were made, such as, molten stainless steel drops, melting of a long term probe, deposition on steel panels, arc traces, loosely bound particles and deposition stripes on the plasma vessel hidden behind the graphite tiles. In order to understand the possible causes, their implication and steps to avoid some of these problems for the next phase of machine operation, an assessment was made. The melting events should be avoided in the future, the others are due to usual PWI mechanisms and will be monitored after each campaign.
Published: 2020
Full Text: View/download PDF

9. 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

10. 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: View/download PDF

11. Bolometer tomography on Wendelstein 7-X for study of radiation asymmetry

Author: W7-X Team, Zhang, D., Burhenn, R., Beidler, C. D., Feng, Y., Thomsen, H., Brandt, C., Buller, S., Reimold, F., Hacker, P., Laube, R., Geiger, J., Regaña, J. M. García, Smith, H. M., König, R., Giannone, L., Penzel, F., Klinger, T., Baldzuhn, J., Bozhenkov, S., Bräuer, T., Brunner, J. K., Buttenschön, B., Damm, H., Endler, M., Effenberg, F., Fuchert, G., Gao, Y., Jakubowski, M., Knauer, J., Kremeyer, T., Krychowiak, M., Kwak, S., Laqua, H. P., Langenberg, A., Otte, M., Pablant, N., Pasch, E., Rahbarnia, K., Pavone, A., Rudischhauser, L., Svensson, J., Killer, C., Windisch, 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, business.industry, media_common.quotation_subject, Bolometer, Radiation, Condensed Matter Physics, 01 natural sciences, Asymmetry, 010305 fluids & plasmas, law.invention, Optics, law, 0103 physical sciences, Tomography, Wendelstein 7-X, 010306 general physics, business, ddc:600, media_common
Published: 2021
Full Text: View/download PDF

12. Wendelstein 7-X on the path to long-pulse high-performance operation

Author: W7-X Team, Endler, M., Baldzuhn, J., Beidler, C. D., Bosch, H.-S., Bozhenkov, S., Buttenschön, B., Dinklage, A., Fellinger, J., Feng, Y., Fuchert, G., Gao, Y., Geiger, J., Grulke, O., Hartmann, D., Jakubowski, M., König, R., Laqua, H. P., Lazerson, S., McNeely, P., Naujoks, D., Neuner, U., Otte, M., Pasch, E., Sunn Pedersen, T., Perseo, V., Puig Sitjes, A., Rahbarnia, K., Rust, N., Schmitz, O., Spring, A., Stange, T., Stechow, A. von, Turkin, Y., Wang, E., 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: Technology, Optimisation, Steady-state, Stellarator, Wendelstein 7-X, Nuclear engineering, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, law.invention, Data acquisition, law, Range (aeronautics), 0103 physical sciences, Water cooling, General Materials Science, 010306 general physics, Civil and Structural Engineering, Steady state, Mechanical Engineering, Fusion power, Nuclear Energy and Engineering, Path (graph theory), ddc:600
Abstract: The Wendelstein 7-X project is aimed at demonstrating that an optimised stellarator is an attractive candidate for a fusion reactor. This requires the achievement of a number of technical and physics goals. Several of these goals have already been achieved in the first three experimental campaigns. We shall exemplify this by a number of results. One important goal is the demonstration of quasi-steady-state operation at high plasma density and temperature for half an hour, which encompasses the physical and technical requirements of stable operation with density and impurity control, cw heating, water-cooled targets, particle exhaust, and an appropriate control and data acquisition system for long-pulse operation. In the previous experimental campaigns, with uncooled targets, stationary discharges for up to 25 s with 5 MW heating power and up to 100 s with 2 MW heating power were achieved. For the next operational phase, to start in 2022, water-cooled targets are being installed, water cooling will be provided for all first-wall components, and a number of further upgrades to plasma heating, vacuum and fuelling systems as well as diagnostics will become available. With this equipment, the further goals of the project will be tackled, including the stepwise extension of discharge intervals to the multi-minute range. The experimental results so far have confirmed the neoclassical theory underlying several of the optimisation goals. At the same time, they showed that an optimisation is also required with respect to anomalous transport. In the future operational phases we aim at building a solid theoretical, experimental and technical foundation for the design of a next-step stellarator device.
Published: 2021
Full Text: View/download PDF

13. Plasma Termination by Excess Pellet Fueling and Impurities in TJ-II, LHD and Wendelstein 7-X

Author: Dinklage, A., McCarthy, K., Suzuki, C., Tamura, N., Wegner, T., Yamada, H., Baldzuhn, J., Buttenschön, B., Damm, H., Drewelow, P., Fuchert, G., Kasahara, H., Maier, D., Miyazawa, J., Motojima, G., Oishi, T., Pedersen, T., Sakamoto, R., Wolf, R., Zhang, D., W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society, LHD Experiment Group, and TJ-II Team
Published: 2019

14. 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

15. Plasma termination by excess pellet fueling and impurity injection in TJ-II, the Large Helical Device and Wendelstein 7-X

Author: Dinklage, A., McCarthy, K. J., Suzuki, C., Tamura, N., Wegner, Th., Yamada, H., Baldzuhn, J., Brunner, K. J., Buttenschön, B., Damm, H., Drewelow, P., Fuchert, G., Hirsch, M., Hoefel, U., Kasahara, H., Knauer, J., Maier, D., Miyazawa, J., Motojima, G., Oishi, T., Rahbarnia, K., Sunn Pedersen, T., Sakamoto, R., Wolf, R. C., 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, Weggen, Jörg, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Subjects: Technology, Nuclear and High Energy Physics, Materials science, Plasma, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Large Helical Device, Impurity, law, 0103 physical sciences, Pellet, Atomic physics, Wendelstein 7-X, 010306 general physics, ddc:600, Stellarator
Published: 2019

16. High density and high performance operation with pellet injection in W7-X

Author: Bozhenkov, S., Kazakov, Y., Baldzuhn, J., Laqua, H., Alonso, J., Beurskens, M., Brandt, C., Brunner, K., Damm, H., Fuchert, G., Hirsch, M., Höfel, U., Jakubowski, M., Knauer, J., Kocsis, G., König, R., Langenberg, A., Lazerson, S., Marushchenko, N., McCarthy, K., Pasch, E., Pablant, N., Panadero Alvarez, N., Rahbarnia, K., Schmitt, J., Thomsen, H., Turkin, Y., Warmer, F., Wurden, G., Zhang, D., Pedersen, T., Wolf, R., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2019

17. 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

18. Investigations of the role of neoclassical transport in ion-root plasmas on W7-X

Author: Pablant, N., Langenberg, A., Alonso, A., Baldzuhn, J., Beidler, C., Böttger, L., Bozhenkov, S., Burhenn, R., Brunner, K., Dinklage, A., Fuchert, G., Ford, O., Gates, D., Geiger, J., Grulke, O., Hirsch, M., Höfel, U., Huang, Z., Kazakov, Y., Knauer, J., Krychowiak, M., Kring, J., Laqua, H., Landreman, M., Lazerson, S., Maaßberg, H., Marchuck, O., Mollen, A., Pasch, E., Pavone, A., Porkolab, M., Satake, S., Schröder, T., Smith, H., Svensson, J., Traverso, P., Turkin, Y., Velasco, J., Stechow, A., Warmer, F., Weir, G., Wolf, R., Zhang, D., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2019

19. Electron-cyclotron-resonance heating in Wendelstein 7-X

Author: Wolf, R. C., Bozhenkov, S., Dinklage, A., Fuchert, G., Kazakov, Y. O., Laqua, H. P., Marsen, S., Marushchenko, N. B., Stange, T., Zanini, M., Abramovic, I., Alonso, A., Baldzuhn, J., Beurskens, M., Beidler, C. D., Braune, H., Brunner, K. J., Chaudhary, N., Damm, H., Drewelow, P., Gantenbein, G., Gao, Y., Geiger, J., Hirsch, M., Hofel, U., Jakubowski, M., Jelonnek, J., Jensen, T., Kasparek, W., Knauer, J., Korsholm, S. B., Langenberg, A., Lechte, C., Leipold, F., Mora, H. T., Neuner, U., Nielsen, S. K., Moseev, D., Oosterbeek, H., Pablant, N., Pasch, E., Plaum, B., Pedersen, T. S., Sitjes, A. P., Rahbarnia, K., Rasmussen, J., Salewski, M., Schilling, J., Scott, E., Stejner, M., Thomsen, H., Thumm, M., Turkin, Y., Wilde, F., Giannella, V., Citarella, R., W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society, and Science and Technology of Nuclear Fusion
Subjects: Physics, Technology, Cyclotron, Plasma, Collisionality, Fusion power, Condensed Matter Physics, 7. Clean energy, 01 natural sciences, Electron cyclotron resonance, Stellerator, 010305 fluids & plasmas, law.invention, Computational physics, Bootstrap current, stellarator, Nuclear Energy and Engineering, law, 0103 physical sciences, Electron temperature, Wendelstein 7-X, electron-cyclotron-resonance heating and current drive, 010306 general physics, ddc:600
Abstract: For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising heating method even for the envisaged application in a fusion power plant. Wendelstein 7-X (W7-X) is equipped with a steady-state capable ECRH system, operating at 140 GHz, which corresponds to the 2nd cyclotron harmonic of the electrons at a magnetic field of 2.5 T. Ten gyrotrons are operational and already delivered 7 MW to W7-X plasmas. Combined with pellet injection, the highest triple product (0.68 ×1020 keV m-3 s), observed up to now in stellarators, was achieved (Sunn Pedersen et al 2018 Plasma Phys. Control. Fusion 61 014035). For the first time, W7-X plasmas were sustained by 2nd harmonic O-mode heating, approaching the collisionality regime for which W7-X was optimized. Power deposition scans did not show any indication of electron temperature profile resilience. In low-density, low-power plasmas a compensation of the bootstrap current with electron-cyclotron current drive (ECCD) was demonstrated. Sufficiently strong ECCD close to the plasma centre produced periodic internal plasma-crash events, which coincide with the appearance of low order rationals of the rotational transform.
Published: 2019
Full Text: View/download PDF

20. Adaptation and benchmarking of the pellet simulation code HPI2 for the stellarators TJ-II and W7-X

Author: Nerea Panadero, Mccarthy, K. J., Baldzuhn, J., La Cal, E., Koechl, F., Iglesias, D., Pastor, I., Velasco, J. L., TJ-II Team, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2019

21. 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

22. 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
Full Text: View/download PDF

23. 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

24. Performance of Wendelstein 7-X stellarator plasmas during the first divertor operation phase

Author: Wolf, R. C., Alonso, A., Akaslompolo, S., Baldzuhn, J., Beurskens, M., Beidler, C. D., Biedermann, C., Bosch, H. -S., Bozhenkov, S., Brakel, R., Braune, H., Brezinsek, S., Brunner, K. -J., Damm, H., Dinklage, A., Drewelow, P., Effenberg, F., Feng, Y., Ford, O., Fuchert, G., Gao, Y., Geiger, J., Grulke, O., Harder, N., Hartmann, D., Helander, P., Heinemann, B., Hirsch, M., Hofel, U., Hopf, C., Ida, K., Isobe, M., Jakubowski, M. W., Kazakov, Y. O., Killer, C., Klinger, T., Knauer, J., Konig, R., Krychowiak, M., Langenberg, A., Laqua, H. P., Lazerson, S., Mcneely, P., Marsen, S., Marushchenko, N., Nocentini, R., Ogawa, K., Orozco, G., Osakabe, M., Otte, M., Pablant, N., Pasch, E., Pavone, A., Porkolab, M., Puig Sitjes, A., Rahbarnia, K., Riedl, R., Rust, N., Scott, E., Schilling, J., Schroeder, R., Stange, T., Von Stechow, A., Strumberger, E., Sunn Pedersen, T., Svensson, J., Thomson, H., Turkin, Y., Vano, L., Wauters, T., Wurden, G., Yoshinuma, M., Zanini, M., Zhang, D., Andreeva, T., Brandt, C., Burhenn, R., Buttenschon, B., Geiger, B., Tamura, N., Thomsen, H., Wegner, T., Abramovic, I., Alcuson, J., Aleynikov, P., Aleynikova, K., Ali, A., Anda, G., Ascasibar, E., Bahner, J. P., Baek, S. G., Balden, M., Banduch, M., Barbui, T., Behr, W., Beidler, C., Benndorf, A., Biel, W., Blackwell, B., Blanco, E., Blatzheim, M., Ballinger, S., Bluhm, T., Bockenhoff, D., Boswirth, B., Bottger, L. -G., Borchardt, M., Borsuk, V., Boscary, J., Brand, H., Brauer, T., Bussiahn, R., Bykov, V., Cai, J., Calvo, I., Cannas, B., Cappa, A., Carls, A., Carralero, D., 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., Dittmar, T., Drevlak, M., Drews, P., Durodie, F., Edlund, E., Van Eeten, P., Ehrke, G., Elgeti, S., Endler, M., Ennis, D., Esteban, H., Estrada, T., Fellinger, J., Flom, E., Fernandes, H., Fietz, W. H., Figacz, W., Fontdecaba, J., Fornal, T., Frerichs, H., Freund, A., Funaba, T., Galkowski, A., Gantenbein, G., Garcia Regana, J., Gates, D., Giannella, V., Gogoleva, A., Goncalves, B., Goriaev, A., Gradic, D., Grahl, M., Green, J., Greuner, H., Grosman, A., Grote, H., Gruca, M., Guerard, C., Hacker, P., Han, X., Harris, J. H., Hathiramani, D., Hein, B., Henneberg, S., Henkel, M., Hernandez Sanchez, J., Hidalgo, C., Hollfeld, K. P., Holting, A., Hoschen, D., Houry, M., Howard, J., Huang, X., Huang, Z., Hubeny, M., Huber, M., Hunger, H., 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., Kirschner, A., Kleiber, R., Knaup, M., Knieps, A., Kobarg, T., Kocsis, G., Kochl, F., Kolesnichenko, Y., Konies, A., Kornejew, P., Koschinsky, J. -P., Koster, F., Kramer, M., Krampitz, R., Kramer-Flecken, A., Krawczyk, N., Kremeyer, T., Krom, J., Ksiazek, I., Kubkowska, M., Kuhner, G., Kurki-Suonio, T., Kurz, P. A., Kwak, S., Landreman, M., Lang, P., Lang, R., Langish, S., Laqua, H., Laube, R., 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., Lucke, A., Lumsdaine, A., Lutsenko, V., Maassberg, H., Marchuk, O., Matthew, J. H., Marushchenko, M., Masuzaki, S., Maurer, D., Mayer, M., Mccarthy, K., Meier, A., Mellein, D., Mendelevitch, B., Mertens, P., Mikkelsen, D., Mishchenko, A., Missal, B., Mittelstaedt, J., Mizuuchi, T., Mollen, A., Moncada, V., Monnich, T., Morisaki, T., Moseev, D., Murakami, S., Nafradi, G., Nagel, M., Naujoks, D., Neilson, H., Neu, R., Neubauer, O., Neuner, U., Ngo, T., Nicolai, D., Nielsen, S. K., Niemann, H., Nishizawa, T., Nuhrenberg, C., Nuhrenberg, J., Obermayer, S., Offermanns, G., Olmanns, J., Ongena, J., Oosterbeek, J. W., Pacios Rodriguez, L., Panadero, N., Panadero Alvarez, N., Papenfuss, D., Paqay, S., Pawelec, E., Pedersen, T. S., Pelka, G., Perseo, V., Peterson, B., Pilopp, D., Pingel, S., Pisano, F., Plaum, B., Plunk, G., Poloskei, P., Proll, J., Puiatti, M. -E., Purps, F., Rack, M., Recsei, S., Reiman, A., Reimold, F., Reiter, D., Remppel, F., Renard, S., Riemann, J., Risse, K., Rohde, V., Rohlinger, H., Rome, M., Rondeshagen, D., Rong, P., Roth, B., Rudischhauser, L., Rummel, K., Rummel, T., Runov, A., Ryc, L., Ryosuke, S., Sakamoto, R., Salewski, M., Samartsev, A., Sanchez, E., Sano, F., Satake, S., Schacht, J., Satheeswaran, G., Schauer, F., Scherer, T., Schlaich, A., Schlisio, G., Schluck, F., Schluter, K. -H., Schmitt, J., Schmitz, H., Schmitz, O., Schmuck, S., Schneider, M., Schneider, W., Scholz, P., Schrittwieser, R., Schroder, M., Schroder, T., Schumacher, H., Schweer, B., Sereda, S., Shanahan, B., Sibilia, M., Sinha, P., Siplia, S., Slaby, C., Sleczka, M., Smith, H., Spiess, W., Spong, D. A., Spring, A., Stadler, R., Stejner, M., Stephey, L., Stridde, U., Suzuki, C., Szabo, V., Szabolics, T., Szepesi, T., Szokefalvi-Nagy, Z., Tancetti, A., Terry, J., Thomas, J., Thumm, M., Travere, J. M., Traverso, P., Tretter, J., Trimino Mora, H., Tsuchiya, H., Tsujimura, T., Tulipan, S., Unterberg, B., Vakulchyk, I., Valet, S., Van Milligen, B., Van Vuuren, A. J., Vela, L., Velasco, J. -L., Vergote, M., Vervier, M., Vianello, N., Viebke, H., Vilbrandt, R., Vorkoper, A., Wadle, S., Wagner, F., Wang, E., Wang, N., Wang, Z., Warmer, F., Wegener, L., Weggen, J., 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., Xanthopoulos, P., Yamada, H., Yamada, I., Yasuhara, R., Yokoyama, M., Zarnstorff, M., Zeitler, A., Zhang, H., Zhu, J., Zilker, M., Zocco, A., Zoletnik, S., Zuin, M., Science and Technology of Nuclear Fusion, Turbulence in Fusion Plasmas, and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Subjects: Physics, Technology, Plasma parameters, Divertor, Nuclear engineering, Plasma, Condensed Matter Physics, 01 natural sciences, 7. Clean energy, Electron cyclotron resonance, 010305 fluids & plasmas, law.invention, Magnetic field, law, 0103 physical sciences, Limiter, Wendelstein 7-X, 010306 general physics, ddc:600, Stellarator
Abstract: Wendelstein 7-X is the first comprehensively optimized stellarator aiming at good confinement with plasma parameters relevant to a future stellarator power plant. Plasma operation started in 2015 using a limiter configuration. After installing an uncooled magnetic island divertor, extending the energy limit from 4 to 80 MJ, operation continued in 2017. For this phase, the electron cyclotron resonance heating (ECRH) capability was extended to 7 MW, and hydrogen pellet injection was implemented. The enhancements resulted in the highest triple product (6.5 × 1019 keV m-3 s) achieved in a stellarator until now. Plasma conditions [Te(0) ≈ Ti(0) ≈ 3.8 keV, τE > 200 ms] already were in the stellarator reactor-relevant ion-root plasma transport regime. Stable operation above the 2nd harmonic ECRH X-mode cutoff was demonstrated, which is instrumental for achieving high plasma densities in Wendelstein 7-X. Further important developments include the confirmation of low intrinsic error fields, the observation of current-drive induced instabilities, and first fast ion heating and confinement experiments. The efficacy of the magnetic island divertor was instrumental in achieving high performance in Wendelstein 7-X. Symmetrization of the heat loads between the ten divertor modules could be achieved by external resonant magnetic fields. Full divertor power detachment facilitated the extension of high power plasmas significantly beyond the energy limit of 80 MJ.
Published: 2019
Full Text: View/download PDF

25. Planned Active Spectroscopy in the Neutral Beam Injectors of W7-X

Author: Baldzuhn, J., Ford, O., Richert, T., and W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2015

26. Supression of High-power Microwave Impact onto Diagnostic Detectors during ECR-heating on Fusion Plasmas

Author: Zhang, D., Burhenn, R., Hirsch, M., Laqua, H., König, R., Oosterbeek, J., Baldzuhn, J., Grodzki, P., Ewert, K., Grosser, K., Cardella, A., and W7-X Team
Published: 2011

27. Diagnostic design for steady-state operation of the W7-X stellarator

Author: König, R., Baldzuhn, J., Hirsch, M., Kornejec, P., Krychowiak, M., Laqua, H., Laux, M., Oosterbeek, J.W., Pasch, E., Richert, T., Schneider, W., Schweer, B., Biel, W., Thomsen, H., Weller, A., Werner, A., Wolf, R., Zhang, D., Biedermann, C., Burhenn, R., Cantarini, J., Dreier, H., Endler, M., Hartfuss, H.J., and Hildebrandt, D.
Subjects: ddc:530
Abstract: The status of the diagnostic developments for the quasistationary operable stellarator Wendelstein 7-X (maximum pulse length of 30 min at 10 MW ECRH heating at 140 GHz) will be reported on. Significant emphasis is being given to the issue of ECRH stray radiation shielding of in-vessel diagnostic components, which will be critical at high density operation requiring O2 and OXB heating.
Published: 2010
Full Text: View/download PDF

28. Transport of Impurity Ions in the Wendelstein 7-AS Stellarator Plasma

Author: Burhenn, R., Baldzuhn, J., Beidler, C., Brakel, R., Ehmler, H., Giannone, L., Grigull, P., Hirsch, M., Knauer, J., Krychowiak, M., Ida, K., Maaßberg, H., McCormick, K., Pasch, E., Weller, A., W7-AS Team, ECRH Group, and NI Group
Published: 2006

29. Physics, technologies, and status of the Wendelstein 7-X device

Author: Wagner, F., Andreeva, T., Cardella, A., Czerwinski, M., Damiani, C., Dammertz, G., Duebner, A., Ehmler, J. H., Elio, F., Endler, M., Erckmann, V., Feist, J., Baldzuhn, J., Fillunger, M., Gantenbein, G., Gardebrecht, W., Gasparotto, M., Giesen, B., Greuner, H., Greve, A. B., Grigull, P., Grote, H., Harmeyer, E., Benndorf, A., Hartfuss, H. J., Hartmann, D., Hein, B., Heinemann, B., Holtum, D., Huguet, M., Hurd, F., Jaksic, N., Kasparek, W., Kissliner, J., Bolt, H., Klinger, T., Knauer, J., Krampitz, R., Laqua, H., Lentz, H., Liesenberg, K., Maier, J., Maix, R., Mendelevitch, B., Michel, G., Boscary, J., Nagel, H. Y., Naujoks, D., Niedermeyer, H., Nuehrenberg, C., Opitz, A., Pfeiffer, G., Pietsch, M., Reich, J., Risse, K., Rong, P., Bosch, H. S., Rummel, K., Rummel, T., Sborchia, C., Schauer, F., Schroeder, R., Schultz, U., Schweizer, S., Simon-Weidner, J., Sochor, M., Sonnerup, L., Braeuer, T., Streibl, B., Tretter, J., Thumm, M., Viebke, H., Wanner, M., Wegener, L., Weissgerber, M., Werner, A., Winkler, M., Brakel, R., and Brand, P.
Published: 2004

30. Impurity transport in the W7-AS stellarator

Author: Burhenn, R., Baldzuhn, J., Brakel, R., Ehmler, H., Giannone, L., Grigull, P., Knauer, J., Krychowiak, M., Hirsch, M., Ida, K., Maaßberg, H., McCormick, K., Pasch, E., Thomsen, H., Weller, A., W7-AS Team, ECRH Group, and NI Group
Published: 2003

31. Improved Performance of the W7-AS Stellarator with the New Island Divertor

Author: Brakel, R., Grigull, P., McCormick, K., Burhenn, R., Feng, Y., Sardei, F., Baldzuhn, J., Ehmler, H., Gadelmeier, F., Giannone, L., Hildebrandt, D., Ida, K., Jaenicke, R., Kisslinger, J., Klinger, T., Knauer, J., König, R., Kühner, G., Laqua, H., Naujoks, D., Niedermeyer, H., Pasch, E., Ramasubramanian, N., Rust, N., Wagner, F., Weller, A., Wenzel, U., Werner, A., and W7-AS Team
Subjects: Physics::Plasma Physics
Abstract: The island divertor concept has successfully been realized at W7-AS. The divertor gives access to a new NBI-heated high density regime with densities up to 4×10²⁰m-3 and energy confinement well above customary scalings. This regime appears promising with respect to the requirements of both confinement and exhaust. Many features are reminiscent of a quiescent H-mode, but plasma particle transport behaves differently. Beyond a threshold density energy confinement approximately doubles whereas particle confinement dramatically decreases. The density profile flattens and the inward impurity pinch is reduced. This eases density control, prevents impurity accumulation, and allows for quasi-stationary conditions with radiation profiles peaked at the edge. At the highest densities partial detachment occurs with a radiated power fraction up to 90% at a tolerable expense of plasma energy. The sub-divertor pressure is sufficient for pumping. Major experimental results, such as the lack of a high recycling phase preceding detachment, are also predicted by the EMC3/EIRENE code.
Published: 2003

32. Penetration studies for deuterium pellets in W7-AS

Author: Baldzuhn, J., Baylor, L., Lyon, J., and W7-AS Team, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2003

33. The Wendelstein W7-AS High Density H-Mode, A Mode for the Future?

Author: McCormick, K., Burhenn, R., Grigull, P., Baldzuhn, J., Bäumel, S., Brakel, R., Ehmler, H., Gadelmeier, F., Giannone, L., Hirsch, M., Holzhauer, E., Jaenicke, R., Klose, S., Knauer, J., Pasch, E., Thomsen, H., Werner, A., W7-AS Team, ECRH Team, and NBI Team
Published: 2003

34. Major results from Wendelstein 7-AS stellarator

Author: Wagner, F., Burhenn, R., Gadelmeier, F., Geiger, J., Hirsch, M., Laqua, H., Weller, A., Werner, A., Bäumel, S., Baldzuhn, J., Brakel, R., Dinklage, A., Grigull, P., Endler, M., Erckmann, V., Ehmler, H., Feng, Y., Fischer, R., Giannone, L., Hartfuss, H., Hildebrandt, D., Holzhauer, E., Igitkhanov, Y., Jaenicke, R., Kick, M., Kislyakov, A., Kreter, A., Kisslinger, J., Klinger, T., Klose, S., Knauer, J., König, R., Kühner, G., Maassberg, H., McCormick, K., Naujoks, D., Niedermeyer, H., Nührenberg, C., Pasch, E., Ramasubramanian, N., Rust, N., Sallander, E., Sardei, F., Wenzel, U., Wobig, H., Würsching, E., Zarnstorff, M., Zoletnik, S., and W7-AS Team
Abstract: W7-AS operates with an island divertor, which utilises the natural edge islands of the low-shear stellarator configuration to divert the plasma. High densities (up to 4×1020m-3) and partly detached divertor conditions have been attained. The details of the divertor operation will be described along with the 3D-efforts to model the divertor observations. At a density beyond 1.5×1020m-3 another confinement bifurcation appears, which allows steady state operation at good energy and low impurity confinement. The transition is possible from a state of normal confinement or from ELMy or quiescent H-modes. Starting with normal confinement, bifurcation is initiated by a broadening of the density profile. This regime can easily be heated above cut-off by ECRH using electron-bernstein-wave mode conversion. The highest beta-values (>3%) are achieved at high density. The relevance of the W7-AS data for Wendelstein 7-X and the Helias-reactor will be discussed.
Published: 2003

35. Essential Elements of the High Density H-Mode on W7-AS

Author: McCormick, K., Burhenn, R., Grigull, P., Baldzuhn, J., Baeumel, S., Brakel, R., Ehmler, H., Gadelmeier, F., Giannone, L., Hirsch, M., Holzhauer, E., Igitkhanov, Y., Jaenicke, R., Klose, S., Knauer, J., Pasch, E., Thomsen, H., Werner, A., W7-AS Team, ECRH-Team, and NBI-Team
Published: 2003

36. Investigation of the beta-limit in the W7-AS stellarator

Author: Weller, A., Geiger, J., Zarnstorff, M., Sallander, E., Klose, S., Werner, A., Baldzuhn, J., Brakel, R., Burhenn, R., Ehmler, H., Gadelmeier, F., Giannone, L., Hartmann, D., Jaenicke, R., Knauer, J., Laqua, H., Nührenberg, C., Pasch, E., Rust, N., Speth, E., Spong, D., Wagner, F., Wenzel, U., W7-AS Team, and NBI Group
Subjects: Physics::Plasma Physics
Abstract: Investigations of the performance and stability of high-beta plasmas have been restarted in W7-AS utilizing higher heating powers and the new divertor system. The combination of beneficial effects resulted in a significant increase of the volume averaged β from 2 % up to 3.1 % and in MHD-quiescent, quasi-stationary discharges at low radiation levels. Experimental studies of equilibrium effects and of MHD mode activity have been performed with the X-ray tomography system. In addition results of computational MHD stability studies are presented, which show an increase of the stability with increasing β due to the pressure induced deepening of the magnetic well in combination with increasing magnetic shear, in qualitative agreement with the experimental data. The maximum achieved β is limited by the available heating power and not by stability effects. The equilibrium β-limit is approached in the case of low-iota configurations. Particularly with regard to current carrying stellarators and comparisons with tokamaks the modification of the stability of high-beta plasmas by significant OH-currents has been investigated.
Published: 2003

37. Plasma profiles in optimized confinement discharges with high ion temperatures after installation of the island divertor in W7-AS

Author: Kreter, A., Baldzuhn, J., Dinklage, A., Ehmler, H., Kick, M., Maaßberg, H., and W7-AS Team, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2003

38. Optimized Confinement discharges with high ion temperatures after installation of the island divertor in W7-AS

Author: Kreter, A., Baldzuhn, J., Ehmler, H., Hirsch, M., Kick, M., Kislyakov, A., Maaßberg, H., and W7-AS Team
Published: 2002

39. Bolometer tomography and density limit of the high density H-mode in the W7-AS Stellarator

Author: Giannone, L., McCormick, K., Baldzuhn, J., Brakel, R., Burhenn, R., Ehmler, H., Feng, Y., Grigull, P., Knauer, J., Pasch, E., Narayanan, R., Rust, N., and W7-AS Team
Published: 2002

40. Recent results from W7-AS with the new radial NBI injector

Author: Rust, N., Baldzuhn, J., Kick, M., Werner, A., and Speth, E.
Published: 2002

41. Major results from Wendelstein 7-AS stellerator

Author: Wagner, F., Burhenn, R., Brakel, R., Dinklage, A., Grigull, P., Endler, M., Erckmann, V., Ehmler, H., Feng, Y., Fischer, R., Gadelmeier, F., LaGiannone, L., Hartfuss, H. J., Hildebrandt, D., Holzhauer, E., Igitkhanov, Y., Jänicke, R., Kick, M., Kislyakov, A., Kreter, A., Kisslinger, J., Klinger, T., Geiger, J., Klose, S., Knauer, J. P., König, R., Kühner, G., Maassberg, H., McCormick, K., Naujoks, D., Niedermeyer, H., Nührenberg, C., Pasch, E., Hirsch, M., Ramasubramanian, N., Rust, N., Sallander, E., Sardei, F., Wenzel, U., Wobig, H., Würsching, E., Zarnstorff, M., Zoletnik, S., Laqua, H. P., Weller, A., Werner, A., Bäumel, S., and Baldzuhn, J.
Published: 2002

42. Comparative study of intrinsic edge impurities in the W7-AS stellerator during high confinement discharges

Author: Ehmler, H., Burhenn, R., Baldzuhn, J., Dinklage, A., Giannone, L., Hartmann, D., Kick, M., Knauer, J., Kreter, A., McCormick, K., Pasch, E., Klinger, T., Weller, A., and W7-AS Team
Published: 2002

43. Calculation of the Radial Electric Field Change during Radial Neutral Beam Injection into the Stellarator W7-AS

Author: Baldzuhn, J. and Werner, A.
Published: 2001

44. Edge Diagnostic Overview for the W7-AS Divertor Phase

Author: McCormick, K., Baldzuhn, J., Fiedler, S., Giannone, L., Grigull, P., Hartfuß, H., Hildebrandt, D., Knauer, J., Kühner, G., Koenig, R., Naujoks, D., and Sallander, J.
Published: 2000

45. A New H-Mode Operational Range in W7-AS

Author: Grigull, P., Hirsch, M., McCormick, K., Baldzuhn, J., Brakel, R., Fiedler, S., Fuchs, C., Giannone, L., Hartfuß, H., Hildebrandt, D., Kißlinger, J., Koenig, R., Kühner, G., Wagner, F., Wobig, H., and W7-AS, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2000

46. Optimised Confinement in W7-AS

Author: Baldzuhn, J., Giannone, L., Kick, M., McCormick, K., and W7-AS, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2000

47. Density Profile Effects in 'H-Mode' Discharges Observed by High Resolution Thomson Scattering at W7-AS

Author: Knauer, J., Kühner, G., Baldzuhn, J., Fiedler, S., Fuchs, C., Giannone, L., Hirsch, M., McCormick, K., Weller, A., Wendland, C., and W7-AS, Max Planck Institute for Plasma Physics, Max Planck Society
Published: 2000

48. Physics of the Density Limit in the W7-AS Stellarator

Author: Giannone, L., Baldzuhn, J., Burhenn, R., Wagner, F., Brakel, R., Fuchs, C., Hartfuß, H., McCormick, K., Weller, A., Wendland, C., Itoh, K., Itoh, S., NBI Team, ECRH Team, and W7-AS Team
Published: 2000

49. Physics of Density Limit in the W7-AS Stellarator

Author: Giannone, L., Baldzuhn, J., Burhenn, R., Grigull, P., Stroth, U., Wagner, F., Brakel, R., Fuchs, C., Hartfuss, H. J., McCormick, K., Weller, A., Wendland, C., NBI Team, ECRH Team, W7-AS Team, Itoh, K., and Itoh, S. I.
Published: 2000

50. Physics of the Density Limit in the W7-AS Stellarator

Author: Giannone, L., Baldzuhn, J., Burhenn, R., Wagner, F., Brakel, R., Fuchs, C., Hartfuß, H.-J., McCormick, K., Weller, A., Wendland, C., NBI Team, ECRH Team, W7-AS Team, Itoh, K., and Itoh, S.-I.
Published: 2000

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Journal

Database

Publisher

80 results on '"Baldzuhn, J."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources