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441 results on '"A Snicker"'

1. Optimizing beam-ion confinement in ITER by adjusting the toroidal phase of the 3-D magnetic fields applied for ELM control

Author

Sanchis, L., Garcia-Munoz, M., Viezzer, E., Loarte, A., Li, L., Liu, Y. Q., Snicker, A., Chen, L., Zonca, F., Pinches, S. D., and Zarzoso, D.

Subjects
Physics - Plasma Physics
Abstract

The confinement of Neutral Beam Injection (NBI) particles in the presence of n=3 Resonant Magnetic Perturbations (RMPs) in 15 MA ITER DT plasmas has been studied using full orbit ASCOT simulations. Realistic NBI distribution functions, and 3D wall and equilibria, including the plasma response to the externally applied 3D fields calculated with MARS-F, have been employed. The observed total fast-ion losses depend on the poloidal spectra of the applied n=3 RMP as well as on the absolute toroidal phase of the applied perturbation with respect to the NBI birth distribution. The absolute toroidal phase of the RMP perturbation does not affect the ELM control capabilities, which makes it a key parameter in the confinement optimization. The physics mechanisms underlying the observed fast-ion losses induced by the applied 3D fields have been studied in terms of the variation of the particle canonical angular momentum ($\delta P_{\phi}$) induced by the applied 3D fields. The presented simulations indicate that the transport is located in an Edge Resonant Transport Layer (ERTL) as observed previously in ASDEX Upgrade studies. Similarly, our results indicate that an overlapping of several linear and nonlinear resonances at the edge of the plasma might be responsible for the observed fast-ion losses. The results presented here may help to optimize the RMP configuration with respect to the NBI confinement in future ITER discharges.

Published
2022
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2. Overview of European efforts and advances in Stellarator power plant studies

Author

Warmer, Felix, Alguacil, J., Biek, D., Bogaarts, T., Bongiovì, G., Bykov, V., Catalán, J.P., Duligal, R.K., Fernández-Berceruelo, I., Giambrone, S., Hume, C., Hrecinuc, M., Kembleton, R., Lion, J., Lyytinen, T., Noguerón Valiente, J.A., Palermo, I., Queral, V., Rapisarda, D., Rutten, W.J., Sanchis, L., Sarasola, X., Sedlak, K., Snicker, A., Sosa, D., and Urgorri, F.R.

Published
2024
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4. Serpent neutronics model of Wendelstein 7-X for 14.1 MeV neutrons

Author

Äkäslompolo, Simppa, Koschinsky, Jan Paul, Kontula, Joona, Bidermann, Christoph, Bozhenkov, Sergey, Kurki-Suonio, Taina, Leppänen, Jaakko, Snicker, Antti, Wolf, Robert, Wurden, Glen, and Team, W7-X

Subjects
Physics - Computational Physics, Physics - Plasma Physics
Abstract

In this work, a Serpent 2 neutronics model of the Wendelstein 7-X (W7-X) stellarator is prepared, and an response function for the Scintillating-Fibre neutron detector (SciFi) is calculated using the model. The neutronics model includes the simplified geometry for the key components of the stellarator itself as well as the torus hall. The objective of the model is to assess the 14.1 MeV neutron flux from deuteron-triton fusions in W7-X, where the neutrons are modelled only until they have slowed down to 1 MeV energy. The key messages of this article are: demonstration of unstructured mesh geometry usage for stellarators, W7-X in particular; technical documentation of the model and first insights in fast neutron behaviour in W7-X, especially related to the SciFi: the model indicates that the superconducting coils are the strongest scatterers and block neutrons from large parts of the plasma. The back-scattering from e.g. massive steel support structures is found to be small. The SciFi will detect neutrons from an extended plasma volume in contrast to having an effective line-of-sight., Comment: Proceedings of the SOFT2020 conference, to be sumbitted to Fusion Engineering and Design

Published
2020
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5. Validation of neutron emission and neutron energy spectrum calculations on MAST with DRESS

Author

Sperduti, Andrea, Klimek, Iwona, Conroy, Sean, Cecconello, Marco, Gorelenkova, Marina, and Snicker, Antti

Subjects
Physics - Plasma Physics
Abstract

The recently developed Directional RElativistic Spectrum Simulator (DRESS) code has been validated for the first time against numerical calculations and experimental measurements performed on MAST. In this validation, the neutron emissivities and rates computed by DRESS are benchmarked against TRANSP/NUBEAM predictions while the neutron energy spectra provided by DRESS taking as input TRANSP/NUBEAM and ASCOT/BBNBI in Gyro-Orbit (GO) mode fast ion distributions are validated against proton pulse height spectra (PHS) measured by the neutron flux monitor. Excellent agreement was found between DRESS and TRANSP/NUBEAM predictions of local and total neutron emission.

Published
2020
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6. High-performance orbit-following code ASCOT5 for Monte Carlo simulations in fusion plasmas

Author

Varje, Jari, Särkimäki, Konsta, Kontula, Joona, Ollus, Patrik, Kurki-Suonio, Taina, Snicker, Antti, Hirvijoki, Eero, and Äkäslompolo, Simppa

Subjects
Physics - Plasma Physics
Abstract

We present a novel implementation of a Monte Carlo particle-following code for solving the distribution function of minority species in fusion plasmas, called ASCOT5, and verify it using theoretical results for neoclassical transport. The code has been developed from ground up with an OpenMP-MPI hybrid paradigm to take full advantage of current and next generation many-core CPUs with multithreading and SIMD operations. Up to 6-fold increase in performance is demonstrated compared to a previous version of the code which only utilizes MPI. The physics model of the code is comprehensively validated against existing theoretical work, and it is shown to faithfully reproduce neoclassical diffusion across three different collisionality regimes. In simulations for realistic tokamak plasmas, including complex non-axisymmetric geometry, ASCOT5 is verified to reproduce results from the previous version ASCOT4., Comment: Draft to be used for reference. Subject to minor edits before submitting to a journal

Published
2019

9. ECCD studies for EU-DEMO plasmas.

Author

Poli, Emanuele, Figini, Lorenzo, Fable, Emiliano, Siccinio, Mattia, Snicker, Antti, Wu, Chuanren, and Zohm, Hartmut

Subjects
CYCLOTRON resonance, TOKAMAKS, PLASMA currents, ELECTRIC power, FUSION reactors
Abstract

The possibility of driving a large fraction of the plasma current in a tokamak reactor employing electron cyclotron waves is investigated for scenarios as envisaged in the European DEMO through beam tracing calculations performed with the TORBEAM code, which assumes a linear regime for power absorption and employs an adjoint method for the determination of the driven current. Comparatively high ECCD efficiency in the inner half of the plasma column can be achieved by injecting the wave from an elevated position. On the other hand, the efficiency deteriorates in the colder, outer part of the plasma, so that a prohibitive amount of power would be needed to sustain the plasma current non-inductively by ECCD only in the considered scenarios. As an alternative scheme, the injection of slow extraordinary wave below the fundamental resonance is considered. The basic physics features of this scenario are discussed. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Overview of ASDEX upgrade results in view of ITER and DEMO

Author

H. Zohm, E. Alessi, C. Angioni, N. Arden, V. Artigues, M. Astrain, O. Asunta, M. Balden, V. Bandaru, A. Banon Navarro, M. Bauer, A. Bergmann, M. Bergmann, J. Bernardo, M. Bernert, A. Biancalani, R. Bielajew, R. Bilato, G. Birkenmeier, T. Blanken, V. Bobkov, A. Bock, L. Bock, T. Body, T. Bolzonella, N. Bonanomi, A. Bortolon, B. Böswirth, C. Bottereau, A. Bottino, H. van den Brand, M. Brenzke, S. Brezinsek, D. Brida, F. Brochard, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, B. Cannas, P. Cano Megías, D. Carlton, M. Carr, P. Carvalho, C. Castaldo, A. Castillo Castillo, A. Cathey, M. Cavedon, C. Cazzaniga, C. Challis, A. Chankin, A. Chomiczewska, C. Cianfarani, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, L. Colas, G. Conway, S. Costea, D. Coster, T. Cote, A.J. Creely, G. Croci, D.J. Cruz Zabala, G. Cseh, I. Cziegler, O. D’Arcangelo, A. Dal Molin, P. David, C. Day, M. de Baar, P. de Marné, R. Delogu, P. Denner, A. Di Siena, M. Dibon, J.J. Dominguez-Palacios Durán, D. Dunai, M. Dreval, M. Dunne, B.P. Duval, R. Dux, T. Eich, S. Elgeti, A. Encheva, B. Esposito, E. Fable, M. Faitsch, D. Fajardo Jimenez, U. Fantz, M. Farnik, H. Faugel, F. Felici, O. Ficker, A. Figueredo, R. Fischer, O. Ford, L. Frassinetti, M. Fröschle, G. Fuchert, J.C. Fuchs, H. Fünfgelder, S. Futatani, K. Galazka, J. Galdon-Quiroga, D. Gallart Escolà, A. Gallo, Y. Gao, S. Garavaglia, M. Garcia Muñoz, B. Geiger, L. Giannone, S. Gibson, L. Gil, E. Giovannozzi, I. Girka, O. Girka, T. Gleiter, S. Glöggler, M. Gobbin, J.C. Gonzalez, J. Gonzalez Martin, T. Goodman, G. Gorini, T. Görler, D. Gradic, G. Granucci, A. Gräter, G. Grenfell, H. Greuner, M. Griener, M. Groth, O. Grover, A. Gude, L. Guimarais, S. Günter, D. Hachmeister, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G. Harrer, J. Harrison, V. Hauer, T. Hayward-Schneider, B. Heinemann, P. Heinrich, T. Hellsten, S. Henderson, P. Hennequin, M. Herschel, S. Heuraux, A. Herrmann, E. Heyn, F. Hitzler, J. Hobirk, K. Höfler, S. Hörmann, J.H. Holm, M. Hölzl, C. Hopf, L. Horvath, T. Höschen, A. Houben, A. Hubbard, A. Huber, K. Hunger, V. Igochine, M. Iliasova, J. Illerhaus, K. Insulander Björk, C. Ionita-Schrittwieser, I. Ivanova-Stanik, S. Jachmich, W. Jacob, N. Jaksic, A. Jansen van Vuuren, F. Jaulmes, F. Jenko, T. Jensen, E. Joffrin, A. Kallenbach, J. Kalis, A. Kappatou, J. Karhunen, C.-P. Käsemann, S. Kasilov, Y. Kazakov, A. Kendl, W. Kernbichler, E. Khilkevitch, M. Kircher, A. Kirk, S. Kjer Hansen, V. Klevarova, F. Klossek, G. Kocsis, M. Koleva, M. Komm, M. Kong, A. Krämer-Flecken, M. Krause, I. Krebs, A. Kreuzeder, K. Krieger, O. Kudlacek, D. Kulla, T. Kurki-Suonio, B. Kurzan, B. Labit, K. Lackner, F. Laggner, A. Lahtinen, P. Lainer, P.T. Lang, P. Lauber, M. Lehnen, L. Leppin, E. Lerche, N. Leuthold, L. Li, J. Likonen, O. Linder, H. Lindl, B. Lipschultz, Y. Liu, Z. Lu, T. Luda Di Cortemiglia, N.C. Luhmann, T. Lunt, A. Lyssoivan, T. Maceina, J. Madsen, A. Magnanimo, H. Maier, J. Mailloux, R. Maingi, O. Maj, E. Maljaars, V. Maquet, A. Mancini, A. Manhard, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Marchetto, M. Markl, L. Marrelli, P. Martin, F. Matos, M. Mayer, P.J. McCarthy, R. McDermott, G. Meng, R. Merkel, A. Merle, H. Meyer, M. Michelini, D. Milanesio, V. Mitterauer, P. Molina Cabrera, M. Muraca, F. Nabais, V. Naulin, R. Nazikian, R.D. Nem, R. Neu, A.H. Nielsen, S.K. Nielsen, T. Nishizawa, M. Nocente, I. Novikau, S. Nowak, R. Ochoukov, J. Olsen, P. Oyola, O. Pan, G. Papp, A. Pau, G. Pautasso, C. Paz-Soldan, M. Peglau, E. Peluso, P. Petersson, C. Piron, U. Plank, B. Plaum, B. Plöckl, V. Plyusnin, G. Pokol, E. Poli, A. Popa, L. Porte, J. Puchmayr, T. Pütterich, L. Radovanovic, M. Ramisch, J. Rasmussen, G. Ratta, S. Ratynskaia, G. Raupp, A. Redl, D. Réfy, M. Reich, F. Reimold, D. Reiser, M. Reisner, D. Reiter, B. Rettino, T. Ribeiro, D. Ricci, R. Riedl, J. Riesch, J.F. Rivero Rodriguez, G. Rocchi, P. Rodriguez-Fernandez, V. Rohde, G. Ronchi, M. Rott, M. Rubel, D.A. Ryan, F. Ryter, S. Saarelma, M. Salewski, A. Salmi, O. Samoylov, L. Sanchis Sanchez, J. Santos, O. Sauter, G. Schall, A. Schlüter, J. Scholte, K. Schmid, O. Schmitz, P.A. Schneider, R. Schrittwieser, M. Schubert, C. Schuster, N. Schwarz, T. Schwarz-Selinger, J. Schweinzer, F. Sciortino, O. Seibold-Benjak, A. Shabbir, A. Shalpegin, S. Sharapov, U. Sheikh, A. Shevelev, G. Sias, M. Siccinio, B. Sieglin, A. Sigalov, A. Silva, C. Silva, D. Silvagni, J. Simpson, S. Sipilä, A. Snicker, E. Solano, C. Sommariva, C. Sozzi, M. Spacek, G. Spizzo, M. Spolaore, A. Stegmeir, M. Stejner, D. Stieglitz, J. Stober, U. Stroth, E. Strumberger, G. Suarez Lopez, W. Suttrop, T. Szepesi, B. Tál, T. Tala, W. Tang, G. Tardini, M. Tardocchi, D. Terranova, M. Teschke, E. Thorén, W. Tierens, D. Told, W. Treutterer, G. Trevisan, M. Tripský, P. Ulbl, G. Urbanczyk, M. Usoltseva, M. Valisa, M. Valovic, S. van Mulders, M. van Zeeland, F. Vannini, B. Vanovac, P. Varela, S. Varoutis, T. Verdier, G. Verdoolaege, N. Vianello, J. Vicente, T. Vierle, E. Viezzer, I. Voitsekhovitch, U. von Toussaint, D. Wagner, X. Wang, M. Weiland, D. Wendler, A.E. White, M. Willensdorfer, B. Wiringer, M. Wischmeier, R. Wolf, E. Wolfrum, Q. Yang, C. Yoo, Q. Yu, R. Zagórski, I. Zammuto, T. Zehetbauer, W. Zhang, W. Zholobenko, A. Zibrov, M. Zilker, C.F.B. Zimmermann, A. Zito, S. Zoletnik, the EUROfusion Tokamak Exploitation Team, and the ASDEX Upgrade Team

Subjects
tokamak, MHD stability, transport modelling, radiative exhaust, disruption physics, ELM free scenarios, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER and EU DEMO. A major objective of the AUG programme is to shed light on the underlying physics of confinement, stability, and plasma exhaust in order to allow reliable extrapolation of results obtained on present day machines to these reactor-grade devices. Concerning pedestal physics, the mitigation of edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found to be consistent with a reduction of the linear peeling-ballooning stability threshold due to the helical deformation of the plasma. Conversely, ELM suppression by RMPs is ascribed to an increased pedestal transport that keeps the plasma away from this boundary. Candidates for this increased transport are locally enhanced turbulence and a locked magnetic island in the pedestal. The enhanced D-alpha (EDA) and quasi-continuous exhaust (QCE) regimes have been established as promising ELM-free scenarios. Here, the pressure gradient at the foot of the H-mode pedestal is reduced by a quasi-coherent mode, consistent with violation of the high-n ballooning mode stability limit there. This is suggestive that the EDA and QCE regimes have a common underlying physics origin. In the area of transport physics, full radius models for both L- and H-modes have been developed. These models predict energy confinement in AUG better than the commonly used global scaling laws, representing a large step towards the goal of predictive capability. A new momentum transport analysis framework has been developed that provides access to the intrinsic torque in the plasma core. In the field of exhaust, the X-Point Radiator (XPR), a cold and dense plasma region on closed flux surfaces close to the X-point, was described by an analytical model that provides an understanding of its formation as well as its stability, i.e., the conditions under which it transitions into a deleterious MARFE with the potential to result in a disruptive termination. With the XPR close to the divertor target, a new detached divertor concept, the compact radiative divertor, was developed. Here, the exhaust power is radiated before reaching the target, allowing close proximity of the X-point to the target. No limitations by the shallow field line angle due to the large flux expansion were observed, and sufficient compression of neutral density was demonstrated. With respect to the pumping of non-recycling impurities, the divertor enrichment was found to mainly depend on the ionisation energy of the impurity under consideration. In the area of MHD physics, analysis of the hot plasma core motion in sawtooth crashes showed good agreement with nonlinear 2-fluid simulations. This indicates that the fast reconnection observed in these events is adequately described including the pressure gradient and the electron inertia in the parallel Ohm’s law. Concerning disruption physics, a shattered pellet injection system was installed in collaboration with the ITER International Organisation. Thanks to the ability to vary the shard size distribution independently of the injection velocity, as well as its impurity admixture, it was possible to tailor the current quench rate, which is an important requirement for future large devices such as ITER. Progress was also made modelling the force reduction of VDEs induced by massive gas injection on AUG. The H-mode density limit was characterised in terms of safe operational space with a newly developed active feedback control method that allowed the stability boundary to be probed several times within a single discharge without inducing a disruptive termination. Regarding integrated operation scenarios, the role of density peaking in the confinement of the ITER baseline scenario (high plasma current) was clarified. The usual energy confinement scaling ITER98( p,y ) does not capture this effect, but the more recent H20 scaling does, highlighting again the importance of developing adequate physics based models. Advanced tokamak scenarios, aiming at large non-inductive current fraction due to non-standard profiles of the safety factor in combination with high normalised plasma pressure were studied with a focus on their access conditions. A method to guide the approach of the targeted safety factor profiles was developed, and the conditions for achieving good confinement were clarified. Based on this, two types of advanced scenarios (‘hybrid’ and ‘elevated’ q -profile) were established on AUG and characterised concerning their plasma performance.

Published
2024
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11. Diagnostic weight functions in constants-of-motion phase-space

Author

M. Rud, D. Moseev, F. Jaulmes, K. Bogar, J. Eriksson, H. Järleblad, M. Nocente, G. Prechel, B.C.G. Reman, B.S. Schmidt, A. Snicker, L. Stagner, A. Valentini, and M. Salewski

Subjects
weight functions, fast ions, diagnostics, constants-of-motion phase-space, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The fast-ion phase-space distribution function in axisymmetric tokamak plasmas is completely described by the three constants of motion: energy, magnetic moment and toroidal canonical angular momentum. In this work, the observable regions of constants-of-motion phase-space, given a diagnostic setup, are identified and explained using projected velocities of the fast ions along the diagnostic lines-of-sight as a proxy for several fast-ion diagnostics, such as fast-ion $\text{D}_{\alpha}$ spectroscopy, collective Thomson scattering, neutron emission spectroscopy and gamma-ray spectroscopy. The observable region in constants-of-motion space is given by a position condition and a velocity condition, and the diagnostic sensitivity is given by a gyro-orbit and a drift-orbit weighting. As a practical example, 3D orbit weight functions quantifying the diagnostic sensitivity to each point in phase-space are computed and investigated for the future COMPASS-Upgrade and MAST-Upgrade tokamaks.

Published
2024
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12. Overview of the EUROfusion Tokamak Exploitation programme in support of ITER and DEMO

Author

E. Joffrin, M. Wischmeier, M. Baruzzo, A. Hakola, A. Kappatou, D. Keeling, B. Labit, E. Tsitrone, N. Vianello, the ASDEX Upgrade Team, JET Contributors, the MAST-U Team, the TCV Team, the WEST Team, the EUROfusion Tokamak Exploitation Team:, D. Abate, J. Adamek, M. Agostini, C. Albert, F.C.P. Albert Devasagayam, S. Aleiferis, E. Alessi, J. Alhage, S. Allan, J. Allcock, M. Alonzo, G. Anastasiou, E. Andersson Sunden, C. Angioni, Y. Anquetin, L. Appel, G.M. Apruzzese, M. Ariola, C. Arnas, J.F. Artaud, W. Arter, O. Asztalos, L. Aucone, M.H. Aumeunier, F. Auriemma, J. Ayllon, E. Aymerich, A. Baciero, F. Bagnato, L. Bähner, F. Bairaktaris, P. Balázs, L. Balbinot, I. Balboa, M. Balden, A. Balestri, M. Baquero Ruiz, T. Barberis, C. Barcellona, O. Bardsley, S. Benkadda, T. Bensadon, E. Bernard, M. Bernert, H. Betar, R. Bianchetti Morales, J. Bielecki, R. Bilato, P. Bilkova, W. Bin, G. Birkenmeier, R. Bisson, P. Blanchard, A. Bleasdale, V. Bobkov, A. Boboc, A. Bock, K. Bogar, P. Bohm, T. Bolzonella, F. Bombarda, N. Bonanomi, L. Boncagni, D. Bonfiglio, R. Bonifetto, M. Bonotto, D. Borodin, I. Borodkina, T.O.S.J. Bosman, C. Bourdelle, C. Bowman, S. Brezinsek, D. Brida, F. Brochard, R. Brunet, D. Brunetti, V. Bruno, R. Buchholz, J. Buermans, H. Bufferand, P. Buratti, A. Burckhart, J. Cai, R. Calado, J. Caloud, S. Cancelli, F. Cani, B. Cannas, M. Cappelli, S. Carcangiu, A. Cardinali, S. Carli, D. Carnevale, M. Carole, M. Carpita, D. Carralero, F. Caruggi, I.S. Carvalho, I. Casiraghi, A. Casolari, F.J. Casson, C. Castaldo, A. Cathey, F. Causa, J. Cavalier, M. Cavedon, J. Cazabonne, M. Cecconello, L. Ceelen, A. Celora, J. Cerovsky, C.D. Challis, R. Chandra, A. Chankin, B. Chapman, H. Chen, M. Chernyshova, A.G. Chiariello, P. Chmielewski, A. Chomiczewska, C. Cianfarani, G. Ciraolo, J. Citrin, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, I.H. Coffey, C. Colandrea, L. Colas, S. Conroy, C. Contre, N.J. Conway, L. Cordaro, Y. Corre, D. Costa, S. Costea, D. Coster, X. Courtois, C. Cowley, T. Craciunescu, G. Croci, A.M. Croitoru, K. Crombe, D.J. Cruz Zabala, G. Cseh, T. Czarski, A. Da Ros, A. Dal Molin, M. Dalla Rosa, Y. Damizia, O. D’Arcangelo, P. David, M. De Angeli, E. De la Cal, E. De La Luna, G. De Tommasi, J. Decker, R. Dejarnac, D. Del Sarto, G. Derks, C. Desgranges, P. Devynck, S. Di Genova, L.E. di Grazia, A. Di Siena, M. Dicorato, M. Diez, M. Dimitrova, T. Dittmar, L. Dittrich, J.J. Domínguez Palacios Durán, P. Donnel, D. Douai, S. Dowson, S. Doyle, M. Dreval, P. Drews, L. Dubus, R. Dumont, D. Dunai, M. Dunne, A. Durif, F. Durodie, G. Durr Legoupil Nicoud, B. Duval, R. Dux, T. Eich, A. Ekedahl, S. Elmore, G. Ericsson, J. Eriksson, B. Eriksson, F. Eriksson, S. Ertmer, A. Escarguel, B. Esposito, T. Estrada, E. Fable, M. Faitsch, N. Fakhrayi Mofrad, A. Fanni, T. Farley, M. Farník, N. Fedorczak, F. Felici, X. Feng, J. Ferreira, D. Ferreira, N. Ferron, O. Fevrier, O. Ficker, A.R. Field, A. Figueiredo, N. Fil, D. Fiorucci, M. Firdaouss, R. Fischer, M. Fitzgerald, M. Flebbe, M. Fontana, J. Fontdecaba Climent, A. Frank, E. Fransson, L. Frassinetti, D. Frigione, S. Futatani, R. Futtersack, S. Gabriellini, D. Gadariya, D. Galassi, K. Galazka, J. Galdon, S. Galeani, D. Gallart, A. Gallo, C. Galperti, M. Gambrioli, S. Garavaglia, J. Garcia, M. Garcia Munoz, J. Gardarein, L. Garzotti, J. Gaspar, R. Gatto, P. Gaudio, M. Gelfusa, J. Gerardin, S.N. Gerasimov, R. Gerru Miguelanez, G. Gervasini, Z. Ghani, F.M. Ghezzi, G. Ghillardi, L. Giannone, S. Gibson, L. Gil, A. Gillgren, E. Giovannozzi, C. Giroud, G. Giruzzi, T. Gleiter, M. Gobbin, V. Goloborodko, A. González Ganzábal, T. Goodman, V. Gopakumar, G. Gorini, T. Görler, S. Gorno, G. Granucci, D. Greenhouse, G. Grenfell, M. Griener, W. Gromelski, M. Groth, O. Grover, M. Gruca, A. Gude, C. Guillemaut, R. Guirlet, J. Gunn, T. Gyergyek, L. Hagg, J. Hall, C.J. Ham, M. Hamed, T. Happel, G. Harrer, J. Harrison, D. Harting, N.C. Hawkes, P. Heinrich, S. Henderson, P. Hennequin, R. Henriques, S. Heuraux, J. Hidalgo Salaverri, J. Hillairet, J.C. Hillesheim, A. Hjalmarsson, A. Ho, J. Hobirk, E. Hodille, M. Hölzl, M. Hoppe, J. Horacek, N. Horsten, L. Horvath, M. Houry, K. Hromasova, J. Huang, Z. Huang, A. Huber, E. Huett, P. Huynh, A. Iantchenko, M. Imrisek, P. Innocente, C. Ionita Schrittwieser, H. Isliker, P. Ivanova, I. Ivanova Stanik, M. Jablczynska, S. Jachmich, A.S. Jacobsen, P. Jacquet, A. Jansen van Vuuren, A. Jardin, H. Järleblad, A. Järvinen, F. Jaulmes, T. Jensen, I. Jepu, S. Jessica, T. Johnson, A. Juven, J. Kalis, J. Karhunen, R. Karimov, A.N. Karpushov, S. Kasilov, Y. Kazakov, P.V. Kazantzidis, W. Kernbichler, HT. Kim, D.B. King, V.G. Kiptily, A. Kirjasuo, K.K. Kirov, A. Kirschner, A. Kit, T. Kiviniemi, F. Kjær, E. Klinkby, A. Knieps, U. Knoche, M. Kochan, F. Köchl, G. Kocsis, J.T.W. Koenders, L. Kogan, Y. Kolesnichenko, Y. Kominis, M. Komm, M. Kong, B. Kool, S.B. Korsholm, D. Kos, M. Koubiti, J. Kovacic, Y. Kovtun, E. Kowalska Strzeciwilk, K. Koziol, M. Kozulia, A. Krämer Flecken, A. Kreter, K. Krieger, U. Kruezi, O. Krutkin, O. Kudlacek, U. Kumar, H. Kumpulainen, M.H. Kushoro, R. Kwiatkowski, M. La Matina, M. Lacquaniti, L. Laguardia, P. Lainer, P. Lang, M. Larsen, E. Laszynska, K.D. Lawson, A. Lazaros, E. Lazzaro, M.Y.K. Lee, S. Leerink, M. Lehnen, M. Lennholm, E. Lerche, Y. Liang, A. Lier, J. Likonen, O. Linder, B. Lipschultz, A. Listopad, X. Litaudon, E. Litherland Smith, D. Liuzza, T. Loarer, P.J. Lomas, J. Lombardo, N. Lonigro, R. Lorenzini, C. Lowry, T. Luda di Cortemiglia, A. Ludvig Osipov, T. Lunt, V. Lutsenko, E. Macusova, R. Mäenpää, P. Maget, C.F. Maggi, J. Mailloux, S. Makarov, K. Malinowski, P. Manas, A. Mancini, D. Mancini, P. Mantica, M. Mantsinen, J. Manyer, M. Maraschek, G. Marceca, G. Marcer, C. Marchetto, S. Marchioni, A. Mariani, M. Marin, M. Markl, T. Markovic, D. Marocco, S. Marsden, L. Martellucci, P. Martin, C. Martin, F. Martinelli, L. Martinelli, J.R. Martin Solis, R. Martone, M. Maslov, R. Masocco, M. Mattei, G.F. Matthews, D. Matveev, E. Matveeva, M.L. Mayoral, D. Mazon, S. Mazzi, C. Mazzotta, G. McArdle, R. McDermott, K. McKay, A.G. Meigs, C. Meineri, A. Mele, V. Menkovski, S. Menmuir, A. Merle, H. Meyer, K. Mikszuta Michalik, D. Milanesio, F. Militello, A. Milocco, I.G. Miron, J. Mitchell, R. Mitteau, V. Mitterauer, J. Mlynar, V. Moiseenko, P. Molna, F. Mombelli, C. Monti, A. Montisci, J. Morales, P. Moreau, J.M. Moret, A. Moro, D. Moulton, P. Mulholland, M. Muraglia, A. Murari, A. Muraro, P. Muscente, D. Mykytchuk, F. Nabais, Y. Nakeva, F. Napoli, E. Nardon, M.F. Nave, R.D. Nem, A. Nielsen, S.K. Nielsen, M. Nocente, R. Nouailletas, S. Nowak, H. Nyström, R. Ochoukov, N. Offeddu, S. Olasz, C. Olde, F. Oliva, D. Oliveira, H.J.C. Oliver, P. Ollus, J. Ongena, F.P. Orsitto, N. Osborne, R. Otin, P. Oyola Dominguez, D.I. Palade, S. Palomba, O. Pan, N. Panadero, E. Panontin, A. Papadopoulos, P. Papagiannis, G. Papp, V.V. Parail, C. Pardanaud, J. Parisi, A. Parrott, K. Paschalidis, M. Passoni, F. Pastore, A. Patel, B. Patel, A. Pau, G. Pautasso, R. Pavlichenko, E. Pawelec, B. Pegourie, G. Pelka, E. Peluso, A. Perek, E. Perelli Cippo, C. Perez Von Thun, P. Petersson, G. Petravich, Y. Peysson, V. Piergotti, L. Pigatto, C. Piron, L. Piron, A. Pironti, F. Pisano, U. Plank, B. Ploeckl, V. Plyusnin, A. Podolnik, Y. Poels, G. Pokol, J. Poley, G. Por, M. Poradzinski, F. Porcelli, L. Porte, C. Possieri, A. Poulsen, I. Predebon, G. Pucella, M. Pueschel, P. Puglia, O. Putignano, T. Pütterich, V. Quadri, A. Quercia, M. Rabinski, L. Radovanovic, R. Ragona, H. Raj, M. Rasinski, J. Rasmussen, G. Ratta, S. Ratynskaia, R. Rayaprolu, M. Rebai, A. Redl, D. Rees, D. Refy, M. Reich, H. Reimerdes, B.C.G. Reman, O. Renders, C. Reux, D. Ricci, M. Richou, S. Rienacker, D. Rigamonti, F. Rigollet, F.G. Rimini, D. Ripamonti, N. Rispoli, N. Rivals, J.F. Rivero Rodriguez, C. Roach, G. Rocchi, S. Rode, P. Rodrigues, J. Romazanov, C.F. Romero Madrid, J. Rosato, R. Rossi, G. Rubino, J. Rueda Rueda, J. Ruiz Ruiz, P. Ryan, D. Ryan, S. Saarelma, R. Sabot, M. Salewski, A. Salmi, L. Sanchis, A. Sand, J. Santos, K. Särkimäki, M. Sassano, O. Sauter, G. Schettini, S. Schmuck, P. Schneider, N. Schoonheere, R. Schramm, R. Schrittwieser, C. Schuster, N. Schwarz, F. Sciortino, M. Scotto D’Abusco, S. Scully, A. Selce, L. Senni, M. Senstius, G. Sergienko, S.E. Sharapov, R. Sharma, A. Shaw, U. Sheikh, G. Sias, B. Sieglin, S.A. Silburn, C. Silva, A. Silva, D. Silvagni, B. Simmendefeldt Schmidt, L. Simons, J. Simpson, L. Singh, S. Sipilä, Y. Siusko, S. Smith, A. Snicker, E.R. Solano, V. Solokha, M. Sos, C. Sozzi, F. Spineanu, G. Spizzo, M. Spolaore, L. Spolladore, C. Srinivasan, A. Stagni, Z. Stancar, G. Stankunas, J. Stober, P. Strand, C.I. Stuart, F. Subba, G.Y. Sun, H.J. Sun, W. Suttrop, J. Svoboda, T. Szepesi, G. Szepesi, B. Tal, T. Tala, P. Tamain, G. Tardini, M. Tardocchi, D. Taylor, G. Telesca, A. Tenaglia, A. Terra, D. Terranova, D. Testa, C. Theiler, E. Tholerus, B. Thomas, E. Thoren, A. Thornton, A. Thrysoe, Q. TICHIT, W. Tierens, A. Titarenko, P. Tolias, E. Tomasina, M. Tomes, E. Tonello, A. Tookey, M. Toscano Jiménez, C. Tsironis, C. Tsui, A. Tykhyy, M. Ugoletti, M. Usoltseva, D.F. Valcarcel, A. Valentini, M. Valisa, M. Vallar, M. Valovic, SI. Valvis, M. van Berkel, D. Van Eester, S. Van Mulders, M. van Rossem, R. Vann, B. Vanovac, J. Varela Rodriguez, J. Varje, S. Vartanian, M. Vecsei, L. Velarde Gallardo, M. Veranda, T. Verdier, G. Verdoolaege, K. Verhaegh, L. Vermare, G. Verona Rinati, J. Vicente, E. Viezzer, L. Vignitchouk, F. Villone, B. Vincent, P. Vincenzi, M.O. Vlad, G. Vogel, I. Voitsekhovitch, I. Voldiner, P. Vondracek, N.M.T. VU, T. Vuoriheimo, C. Wade, E. Wang, T. Wauters, M. Weiland, H. Weisen, N. Wendler, D. Weston, A. Widdowson, S. Wiesen, M. Wiesenberger, T. Wijkamp, M. Willensdorfer, T. Wilson, A. Wojenski, C. Wuethrich, I. Wyss, L. Xiang, S. Xu, D. Yadykin, Y. Yakovenko, H. Yang, V. Yanovskiy, R. Yi, B. Zaar, G. Zadvitskiy, L. Zakharov, P. Zanca, D. Zarzoso, Y. Zayachuk, J. Zebrowski, M. Zerbini, P. Zestanakis, C. F. B. Zimmermann, M. Zlobinski, A. Zohar, V.K. Zotta, X. Zou, M. Zuin, M. Zurita, and I. Zychor

Subjects
JET, ASDEX Upgrade, MAST-U, TCV, WEST, Tokamak Exploitation Task Force, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Within the 9th European Framework programme, since 2021 EUROfusion is operating five tokamaks under the auspices of a single Task Force called ‘Tokamak Exploitation’. The goal is to benefit from the complementary capabilities of each machine in a coordinated way and help in developing a scientific output scalable to future largre machines. The programme of this Task Force ensures that ASDEX Upgrade, MAST-U, TCV, WEST and JET (since 2022) work together to achieve the objectives of Missions 1 and 2 of the EUROfusion Roadmap: i) demonstrate plasma scenarios that increase the success margin of ITER and satisfy the requirements of DEMO and, ii) demonstrate an integrated approach that can handle the large power leaving ITER and DEMO plasmas. The Tokamak Exploitation task force has therefore organized experiments on these two missions with the goal to strengthen the physics and operational basis for the ITER baseline scenario and for exploiting the recent plasma exhaust enhancements in all four devices (PEX: Plasma EXhaust) for exploring the solution for handling heat and particle exhaust in ITER and develop the conceptual solutions for DEMO. The ITER Baseline scenario has been developed in a similar way in ASDEX Upgrade, TCV and JET. Key risks for ITER such as disruptions and run-aways have been also investigated in TCV, ASDEX Upgrade and JET. Experiments have explored successfully different divertor configurations (standard, super-X, snowflakes) in MAST-U and TCV and studied tungsten melting in WEST and ASDEX Upgrade. The input from the smaller devices to JET has also been proven successful to set-up novel control schemes on disruption avoidance and detachment.

Published
2024
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13. EUROfusion contributions to ITER nuclear operation

Author

X. Litaudon, U. Fantz, R. Villari, V. Toigo, M.-H. Aumeunier, J.-L. Autran, P. Batistoni, E. Belonohy, S. Bradnam, M. Cecchetto, A. Colangeli, F. Dacquait, S. Dal Bello, M. Dentan, M. De Pietri, J. Eriksson, M. Fabbri, G. Falchetto, L. Figini, J. Figueiredo, D. Flammini, N. Fonnesu, L. Frassinetti, J. Galdón-Quiroga, R. Garcia-Alia, M. Garcia-Munoz, Z. Ghani, J. Gonzalez-Martin, E. Grelier, L. Di Grazia, B. Grove, C.L. Grove, A. Gusarov, B. Heinemann, A. Hjalmarsson, O. Hyvärinen, V. Ioannou-Sougleridis, L. Jones, H.-T. Kim, M. Kłosowski, M. Kocan, B. Kos, L. Kos, D. Kotnik, E. Laszynska, D. Leichtle, I. Lengar, E. Leon-Gutierrez, A.J. López-Revelles, S. Loreti, M. Loughlin, D. Marcuzzi, K.G. Mcclements, G. Mariano, M. Mattei, K. Mergia, J. Mietelski, R. Mitteau, S. Moindjie, D. Munteanu, R. Naish, S. Noce, L.W. Packer, S. Pamela, R. Pampin, A. Pau, A. Peacock, E. Peluso, Y. Peneliau, J. Peric, V. Radulović, D. Ricci, F. Rimini, L. Sanchis-Sanchez, P. Sauvan, M.I. Savva, G. Serianni, C.R. Shand, A. Snicker, L. Snoj, I.E. Stamatelatos, Ž. Štancar, N. Terranova, T. Vasilopoulou, R. Vila, J. Waterhouse, C. Wimmer, D. Wünderlich, A. Žohar, the NBTF Team, JET Contributors, and the EUROfusion Tokamak Exploitation Team

Subjects
nuclear fusion, tokamak operation, neutral beam heating and current drive, neutronics, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

ITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called ‘ Pr eparation of I TER O peration’ (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16–21 October 2023) London, UK [ https://www.iaea.org/events/fec2023 ]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium–tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc).

Published
2024
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14. Orbit tomography in constants-of-motion phase-space

Author

M. Rud, D. Moseev, F. Jaulmes, K. Bogar, Y. Dong, P.C. Hansen, J. Eriksson, H. Järleblad, M. Nocente, G. Prechel, B.C.G. Reman, B.S. Schmidt, A. Snicker, L. Stagner, A. Valentini, and M. Salewski

Subjects
fast ions, diagnostics, tomography, orbits, constants of motion, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Tomographic reconstructions of a 3D fast-ion constants-of-motion phase-space distribution function are computed by inverting synthetic signals based on projected velocities of the fast ions along the diagnostic lines of sight. A spectrum of projected velocities is a key element of the spectrum formation in fast-ion D-alpha spectroscopy, collective Thomson scattering, and gamma-ray and neutron emission spectroscopy, and it can hence serve as a proxy for any of these. The fast-ion distribution functions are parameterised by three constants of motion, the kinetic energy, the magnetic moment and the toroidal canonical angular momentum. The reconstructions are computed using both zeroth-order and first-order Tikhonov regularisation expressed in terms of Bayesian inference to allow uncertainty quantification. In addition to this, a discontinuity appears to be present in the solution across the trapped-passing boundary surface in the three-dimensional phase space due to a singularity in the Jacobian of the transformation from position and velocity space to phase space. A method to allow for this apparent discontinuity while simultaneously penalising large gradients in the solution is demonstrated. Finally, we use our new methods to optimise the diagnostic performance of a set of six fans of sightlines by finding where the detectors contribute most complementary diagnostic information for the future COMPASS-Upgrade tokamak.

Published
2024
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15. Proof-of-principle of parametric stellarator neutronics modeling using Serpent2

Author

T. Lyytinen, A. Snicker, J. Virtanen, I. Palermo, J. Alguacil, Timo Bogaarts, and F. Warmer

Subjects
neutronics, HELIAS, parametric modeling, stellarator, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

This contribution presents neutron transport studies for the 5-period helical-axis advanced stellarator stellarator using the Serpent2 code. These studies utilize a parametric geometry model, enabling scans in neutronics modeling by varying the thickness of the reactor layers. For example, the tritium breeding ratio (TBR) can be determined by exploring various blanket material options and thicknesses to identify the threshold configuration that meets the TBR design criterion of 1.15. We found out that with the helium-cooled pebble ped candidate option, the TBR criterion is met with a breeding zone thickness of 26 cm, while with the dual-coolant lithium lead the threshold is exceeded at a thickness of 46 cm. Furthermore, the geometry includes non-planar field coils, allowing to study the fast neutron flux in these superconducting coils with a technological limit of $1\times10^{9}\,1/\mathrm{cm}^{2}\,\mathrm{s}$ . It is shown that the neutron fast flux is not constant at the coils, necessitating a neutron transport simulation to determine the distribution of the fast-flux at the coils. We show that the peak fast flux can be more than a factor of 2 higher than the average flux, and that the peak flux location rotates helically.

Published
2024
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16. The deteriorating effect of plasma density fluctuations on microwave beam quality

Author

Köhn, Alf, Austin, Max E., Brookman, Michael W., Gentle, Kenneth W., Guidi, Lorenzo, Holzhauer, Eberhard, La Haye, Rob J., Leddy, Jarrod B., Maj, Omar, Petty, Craig C., Poli, Emanuele, Rhodes, Terry L., Snicker, Antti, Thomas, Matthew B., Vann, Roddy G. L., and Weber, Hannes

Subjects
Physics - Plasma Physics
Abstract

Turbulent plasma edge density fluctuations can broaden a traversing microwave beam degrading its quality. This can be a problem for scenarios relying on a high spatial localization of the deposition of injected microwave power, like controlling MHD instabilities. Here we present numerical estimations of the scattering of a microwave beam by density fluctuations over a large parameter range, including extrapolations to ITER. Two codes are used, the full-wave code IPF-FDMC and the wave kinetic equation solver WKBeam. A successful comparison between beam broadening obtained from DIII-D experiments and corresponding full-wave simulations is shown., Comment: EPJ Web of Conferences, EC-20 2018 Proceedings, submitted

Published
2018
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18. Microwave beam broadening due to turbulent plasma density fluctuations within the limit of the Born approximation and beyond

Author

Köhn, Alf, Guidi, Lorenzo, Holzhauer, Eberhard, Maj, Omar, Poli, Emanuele, Snicker, Antti, and Weber, Hannes

Subjects
Physics - Plasma Physics
Abstract

Plasma turbulence, and edge density fluctuations in particular, can under certain conditions broaden the cross-section of injected microwave beams significantly. This can be a severe problem for applications relying on well-localized deposition of the microwave power, like the control of MHD instabilities. Here we investigate this broadening mechanism as a function of fluctuation level, background density and propagation length in a fusion-relevant scenario using two numerical codes, the full-wave code IPF-FDMC and the novel wave kinetic equation solver WKBeam. The latter treats the effects of fluctuations using a statistical approach, based on an iterative solution of the scattering problem (Born approximation). The full-wave simulations are used to benchmark this approach. The Born approximation is shown to be valid over a large parameter range, including ITER-relevant scenarios., Comment: This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IoP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it

Published
2017
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20. Orbit tomography in constants-of-motion phase-space

Author

Larsen, Mads Rud, primary, Moseev, Dmitry, additional, Jaulmes, Fabien, additional, Bogar, Klara, additional, Dong, Yiqiu, additional, Hansen, Per Christian, additional, Eriksson, Jacob, additional, Järleblad, Henrik, additional, Nocente, Massimo, additional, Prechel, Garrett, additional, Reman, Bernard C G, additional, Schmidt, Bo Simmendefeldt, additional, Snicker, Antti, additional, Stagner, Luke, additional, Valentini, Andrea, additional, and Salewski, Mirko, additional

Published
2024
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21. Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Author

Wu, Chuanren, Aiello, Gaetano, Avramidis, Konstantinos A., Bruschi, Alessandro, Fable, Emiliano, Franke, Thomas, Gantenbein, Gerd, Garavaglia, Saul, Granucci, Gustavo, Illy, Stefan, Janky, Filip, Jelonnek, John, Kudláček, Ondřej, Moro, Alessandro, Poli, Emanuele, Ruess, Tobias, Scherer, Theo, Schramm, Raphael, Siccinio, Mattia, Snicker, Antti, Strauß, Dirk, Suárez López, Guillermo, Tardini, Giovanni, Thumm, Manfred, Tran, Minh Quang, and Zohm, Hartmut

Published
2021
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23. Diagnostic weight functions in constants-of-motion phase-space

Author

Rud, M., Moseev, D., Jaulmes, F., Bogar, K., Eriksson, Jacob, Järleblad, H., Nocente, M., Prechel, G., Reman, B. C. G., Schmidt, B. S., Snicker, A., Stagner, L., Valentini, A., Salewski, M., Rud, M., Moseev, D., Jaulmes, F., Bogar, K., Eriksson, Jacob, Järleblad, H., Nocente, M., Prechel, G., Reman, B. C. G., Schmidt, B. S., Snicker, A., Stagner, L., Valentini, A., and Salewski, M.

Abstract

The fast-ion phase-space distribution function in axisymmetric tokamak plasmas is completely described by the three constants of motion: energy, magnetic moment and toroidal canonical angular momentum. In this work, the observable regions of constants-of-motion phase-space, given a diagnostic setup, are identified and explained using projected velocities of the fast ions along the diagnostic lines-of-sight as a proxy for several fast-ion diagnostics, such as fast-ion D alpha spectroscopy, collective Thomson scattering, neutron emission spectroscopy and gamma-ray spectroscopy. The observable region in constants-of-motion space is given by a position condition and a velocity condition, and the diagnostic sensitivity is given by a gyro-orbit and a drift-orbit weighting. As a practical example, 3D orbit weight functions quantifying the diagnostic sensitivity to each point in phase-space are computed and investigated for the future COMPASS-Upgrade and MAST-Upgrade tokamaks.

Published
2024
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24. Diagnostic weight functions in constants-of-motion phase-space

Author

Rud, M, Moseev, D, Jaulmes, F, Bogar, K, Eriksson, J, Järleblad, H, Nocente, M, Prechel, G, Reman, B, Schmidt, B, Snicker, A, Stagner, L, Valentini, A, Salewski, M, Reman, BCG, Schmidt, BS, Rud, M, Moseev, D, Jaulmes, F, Bogar, K, Eriksson, J, Järleblad, H, Nocente, M, Prechel, G, Reman, B, Schmidt, B, Snicker, A, Stagner, L, Valentini, A, Salewski, M, Reman, BCG, and Schmidt, BS

Abstract

The fast-ion phase-space distribution function in axisymmetric tokamak plasmas is completely described by the three constants of motion: energy, magnetic moment and toroidal canonical angular momentum. In this work, the observable regions of constants-of-motion phase-space, given a diagnostic setup, are identified and explained using projected velocities of the fast ions along the diagnostic lines-of-sight as a proxy for several fast-ion diagnostics, such as fast-ion D alpha spectroscopy, collective Thomson scattering, neutron emission spectroscopy and gamma-ray spectroscopy. The observable region in constants-of-motion space is given by a position condition and a velocity condition, and the diagnostic sensitivity is given by a gyro-orbit and a drift-orbit weighting. As a practical example, 3D orbit weight functions quantifying the diagnostic sensitivity to each point in phase-space are computed and investigated for the future COMPASS-Upgrade and MAST-Upgrade tokamaks.

Published
2024

25. EUROfusion contributions to ITER nuclear operation

Author

Litaudon, X., Fantz, U., Villari, R., Toigo, V., Aumeunier, M. -H, Autran, J. -L, Batistoni, P., Belonohy, E., Bradnam, S., Cecchetto, M., Colangeli, A., Dacquait, F., Dal Bello, S., Dentan, M., De Pietri, M., Eriksson, Jacob, Fabbri, M., Falchetto, G., Figini, L., Figueiredo, J., Flammini, D., Fonnesu, N., Frassinetti, L., Galdon-Quiroga, J., Garcia-Alia, R., Garcia-Munoz, M., Ghani, Z., Gonzalez-Martin, J., Grelier, E., Di Grazia, L., Grove, B., Grove, C. L., Gusarov, A., Heinemann, B., Hjalmarsson, Anders, Hyvarinen, O., Ioannou-Sougleridis, V., Jones, L., Kim, H. -T, Klosowski, M., Kocan, M., Kos, B., Kos, L., Kotnik, D., Laszynska, E., Leichtle, D., Lengar, I., Leon-Gutierrez, E., Lopez-Revelles, A. J., Loreti, S., Loughlin, M., Marcuzzi, D., Mcclements, K. G., Mariano, G., Mattei, M., Mergia, K., Mietelski, J., Mitteau, R., Moindjie, S., Munteanu, D., Naish, R., Noce, S., Packer, L. W., Pamela, S., Pampin, R., Pau, A., Peacock, A., Peluso, E., Peneliau, Y., Peric, J., Radulovic, V., Ricci, D., Rimini, F., Sanchis-Sanchez, L., Sauvan, P., Savva, M. I., Serianni, G., Shand, C. R., Snicker, A., Snoj, L., Stamatelatos, I. E., Stancar, Z., Terranova, N., Vasilopoulou, T., Vila, R., Waterhouse, J., Wimmer, C., Wuenderlich, D., Zohar, A., Litaudon, X., Fantz, U., Villari, R., Toigo, V., Aumeunier, M. -H, Autran, J. -L, Batistoni, P., Belonohy, E., Bradnam, S., Cecchetto, M., Colangeli, A., Dacquait, F., Dal Bello, S., Dentan, M., De Pietri, M., Eriksson, Jacob, Fabbri, M., Falchetto, G., Figini, L., Figueiredo, J., Flammini, D., Fonnesu, N., Frassinetti, L., Galdon-Quiroga, J., Garcia-Alia, R., Garcia-Munoz, M., Ghani, Z., Gonzalez-Martin, J., Grelier, E., Di Grazia, L., Grove, B., Grove, C. L., Gusarov, A., Heinemann, B., Hjalmarsson, Anders, Hyvarinen, O., Ioannou-Sougleridis, V., Jones, L., Kim, H. -T, Klosowski, M., Kocan, M., Kos, B., Kos, L., Kotnik, D., Laszynska, E., Leichtle, D., Lengar, I., Leon-Gutierrez, E., Lopez-Revelles, A. J., Loreti, S., Loughlin, M., Marcuzzi, D., Mcclements, K. G., Mariano, G., Mattei, M., Mergia, K., Mietelski, J., Mitteau, R., Moindjie, S., Munteanu, D., Naish, R., Noce, S., Packer, L. W., Pamela, S., Pampin, R., Pau, A., Peacock, A., Peluso, E., Peneliau, Y., Peric, J., Radulovic, V., Ricci, D., Rimini, F., Sanchis-Sanchez, L., Sauvan, P., Savva, M. I., Serianni, G., Shand, C. R., Snicker, A., Snoj, L., Stamatelatos, I. E., Stancar, Z., Terranova, N., Vasilopoulou, T., Vila, R., Waterhouse, J., Wimmer, C., Wuenderlich, D., and Zohar, A.

Abstract

ITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called 'Preparation of ITER Operation' (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16-21 October 2023) London, UK [www.iaea.org/events/fec2023]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium-tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc).

Published
2024
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26. Orbit tomography in constants-of-motion phase-space

Author

Rud, M., Moseev, D., Jaulmes, F., Bogar, K., Dong, Y., Hansen, P. C., Eriksson, Jacob, Jaerleblad, H., Nocente, M., Prechel, G., Reman, B. C. G., Schmidt, B. S., Snicker, A., Stagner, L., Valentini, A., Salewski, M., Rud, M., Moseev, D., Jaulmes, F., Bogar, K., Dong, Y., Hansen, P. C., Eriksson, Jacob, Jaerleblad, H., Nocente, M., Prechel, G., Reman, B. C. G., Schmidt, B. S., Snicker, A., Stagner, L., Valentini, A., and Salewski, M.

Abstract

Tomographic reconstructions of a 3D fast-ion constants-of-motion phase-space distribution function are computed by inverting synthetic signals based on projected velocities of the fast ions along the diagnostic lines of sight. A spectrum of projected velocities is a key element of the spectrum formation in fast-ion D-alpha spectroscopy, collective Thomson scattering, and gamma-ray and neutron emission spectroscopy, and it can hence serve as a proxy for any of these. The fast-ion distribution functions are parameterised by three constants of motion, the kinetic energy, the magnetic moment and the toroidal canonical angular momentum. The reconstructions are computed using both zeroth-order and first-order Tikhonov regularisation expressed in terms of Bayesian inference to allow uncertainty quantification. In addition to this, a discontinuity appears to be present in the solution across the trapped-passing boundary surface in the three-dimensional phase space due to a singularity in the Jacobian of the transformation from position and velocity space to phase space. A method to allow for this apparent discontinuity while simultaneously penalising large gradients in the solution is demonstrated. Finally, we use our new methods to optimise the diagnostic performance of a set of six fans of sightlines by finding where the detectors contribute most complementary diagnostic information for the future COMPASS-Upgrade tokamak.

Published
2024
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27. Relativistic calculations of neutron and gamma-ray spectra from beam-target reactions in magnetized plasmas

Author

Valentini, A., Reman, B. C. G., Nocente, M., Eriksson, Jacob, Jarleblad, H., Moseev, D., Rud, M., Snicker, A., Salewski, M., Valentini, A., Reman, B. C. G., Nocente, M., Eriksson, Jacob, Jarleblad, H., Moseev, D., Rud, M., Snicker, A., and Salewski, M.

Abstract

We present a fully relativistic analytical model for calculating synthetic spectra from beam-target fusion reactions. When the target particle is assumed at rest, Monte Carlo sampling of reactant velocities can be avoided, and spectrum computations are considerably faster. A fully analytical treatment additionally gives more insight into the spectrum formation. The fully relativistic formulation now makes it possible to handle massless particles in the model, for example from one-step gamma-ray reactions, and the results are corroborated by simulations from established codes.

Published
2024
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28. Modelling of Energetic Particle Drive and Damping Effects on TAEs in AUG Experiment with ECCD

Author

Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla. Departamento de Ingeniería Mecánica y de Fabricación, European Union (UE), Fundação para a Ciência e a Tecnologia. Portugal, Calado, R., Nabais, F., Sharapov, S. E., Schneider, P., Kazakov, Ye., García Muñoz, Manuel, Snicker, A., Ferreira, J., Coelho, R., Dreval, M., Fuertes, J., Galdón Quiroga, Joaquín, Gonzalez Martin, Javier, Karpushov, A., Stober, J., Tardini, G., Van Zeeland, M. A., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla. Departamento de Ingeniería Mecánica y de Fabricación, European Union (UE), Fundação para a Ciência e a Tecnologia. Portugal, Calado, R., Nabais, F., Sharapov, S. E., Schneider, P., Kazakov, Ye., García Muñoz, Manuel, Snicker, A., Ferreira, J., Coelho, R., Dreval, M., Fuertes, J., Galdón Quiroga, Joaquín, Gonzalez Martin, Javier, Karpushov, A., Stober, J., Tardini, G., and Van Zeeland, M. A.

Abstract

The impact of electron cyclotron current drive (ECCD)-driven current on toroidicity-induced Alfvén eigenmodes (TAEs) in experiments on the AUG tokamak is investigated numerically. The dynamical evolution of the plasma profiles and equilibria are modelled with European transport solver, while ion cyclotron resonance heating-accelerated H-minority ions exciting TAEs are assessed with the PION code. TAEs, their drive and damping are computed with the codes CASTOR and CASTOR-K. In the set of discharges analysed, two groups of TAEs are observed, differing in frequency and radial location. Experimental observations show that when counter-ECCD is applied the higher frequency group of approximately 150 kHz is suppressed, while the lower frequency modes of 125 kHz are amplified. When co-ECCD is applied, depending on the location of the ECCD current deposition layer, both groups of TAE can be suppressed. Numerical calculations of energetic particle drive and thermal plasma damping show that neither one effect could explain the variety of the experimental observations. The fine balance between the drive, sensitive to the TAE position, and the radiative and continuum damping effects could only explain the experiment if the effects are considered all together.

Published
2024

29. Simulations of fast ion wall loads in ASDEX Upgrade in the presence of magnetic perturbations due to ELM mitigation coils

Author

Asunta, Otto, Äkäslompolo, Simppa, Kurki-Suonio, Taina, Koskela, Tuomas, Sipilä, Seppo, Snicker, Antti, and Garcia-Muñoz, Manuel

Subjects
Physics - Plasma Physics, Physics - Computational Physics
Abstract

The effect of ASDEX Upgrade (AUG) ELM mitigation coils on fast ion wall loads was studied with the fast particle following Monte Carlo code ASCOT. Neutral beam injected (NBI) particles were simulated in two AUG discharges both in the presence and in the absence of the magnetic field perturbation induced by the eight newly installed in-vessel coils. In one of the discharges (#26476) beams were applied individually, making it a useful basis for investigating the effect of the coils on different beams. However, no ELM mitigation was observed in #26476, probably due to the low plasma density. Therefore, another discharge (#26895) demonstrating clear ELM mitigation was also studied. The magnetic perturbation due to the in-vessel coils has a significant effect on the fast particle confinement, but only when total magnetic field, $B_{tot}$, is low. When $B_{tot}$ was high, the perturbation did not increase the losses, but merely resulted in redistribution of the wall power loads. Hence, it seems to be possible to achieve ELM mitigation using in-vessel coils, while still avoiding increased fast ion losses, by simply using a strong $B_{tot}$. Preliminary comparisons between simulated and experimental Fast Ion Lost Detector (FILD) signals show a reasonable correspondence.

Published
2015
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30. Calculating the 3D magnetic field of ITER for European TBM studies

Author

Äkäslompolo, Simppa, Asunta, Otto, Bergmans, Thijs, Gagliardi, Mario, Galabert, Jose, Hirvijoki, Eero, Kurki-Suonio, Taina, Sipilä, Seppo, and Snicker, Antti

Subjects
Physics - Plasma Physics, Physics - Computational Physics
Abstract

The magnetic perturbation due to the ferromagnetic test blanket modules (TBMs) may deteriorate fast ion confinement in ITER. This effect must be quantified by numerical studies in 3D. We have implemented a combined finite element method (FEM) -- Biot-Savart law integrator method (BSLIM) to calculate the ITER 3D magnetic field and vector potential in detail. Unavoidable geometry simplifications changed the mass of the TBMs and ferritic inserts (FIs) up to 26%. This has been compensated for by modifying the nonlinear ferromagnetic material properties accordingly. Despite the simplifications, the computation geometry and the calculated fields are highly detailed. The combination of careful FEM mesh design and using BSLIM enables the use of the fields unsmoothed for particle orbit-following simulations. The magnetic field was found to agree with earlier calculations and revealed finer details. The vector potential is intended to serve as input for plasma shielding calculations., Comment: In proceedings of the 28th Symposium on Fusion Technology

Published
2015
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31. EUROFUSION CONTRIBUTIONS TO ITER NUCLEAR OPERATION

Author

Litaudon, Xavier L, primary, Fantz, Ursel, additional, Villari, Rosaria, additional, Toigo, Vanni, additional, Aumeunier, Marie-Helene, additional, Autran, Jean-Luc, additional, Batistoni, Paola, additional, Belonohy, Eva, additional, Bradnam, Steven, additional, CECCHETTO, Matteo, additional, Colangeli, Andrea, additional, DACQUAIT, Frederic, additional, Dal Bello, Samuele, additional, DENTAN, Martin, additional, De Pietri, Marco, additional, Eriksson, Jacob, additional, Fabbri, Marco, additional, Falchetto, Gloria L, additional, Figini, Lorenzo, additional, Figueiredo, Joao, additional, Flammini, Davide, additional, Fonnesu, Nicola, additional, Frassinetti, Lorenzo, additional, Galdon-Quiroga, Joaquin, additional, Garcia Alia, Ruben, additional, Garcia-Munoz, Manuel, additional, Ghani, Zamir, additional, Gonzalez Martin, Javier, additional, Grelier, Erwan, additional, DIGRAZIA, Luigi Manuel, additional, Grove, Bob, additional, GROVE, Callum, additional, GUSAROV, Andrei, additional, Heinemann, Bernd, additional, Hjalmarsson, Anders, additional, Hyvarinen, otsojuhani, additional, Ioannou-Sougleridis, Vassilios, additional, JONES, Luke, additional, Kim, Hyun-Tae, additional, Klosowski, Marius, additional, Kocan, Martin, additional, Kos, Bor, additional, Kos, Leon, additional, Kotnik, Domen, additional, Laszynska, Ewa, additional, Leichtle, Dieter, additional, Lengar, Igor, additional, Leon-Gutierrez, Edgard, additional, López Revelles, Antonio Jesús, additional, Loreti, Stefano, additional, LOUGHLIN, Mike J, additional, Marcuzzi, Diego, additional, McClements, Kenneth G, additional, Mariano, Giovanni, additional, Mattei, Massimiliano, additional, Mergia, K, additional, Mietelski, Jerzy, additional, Mitteau, Raphael, additional, Moindjie, soilihi, additional, Munteanu, Daniela, additional, Naish, Richard, additional, NOCE, simone, additional, Packer, Lee, additional, Pamela, Stanislas, additional, Pampin, Raul, additional, Pau, Alessandro, additional, Peacock, Alan, additional, Peluso, Emmanuele, additional, Peneliau, Yannick, additional, Peric, julijan, additional, Radulovic, Vladimir, additional, Ricci, Daria, additional, Rimini, Fernanda, additional, Sauvan, Patrick, additional, Savva, Marilia, additional, Serianni, Gianluigi, additional, SHAND, Chantal, additional, Snicker, Antti, additional, Snoj, Luka, additional, Stamatelatos, Ion, additional, Štancar, Žiga, additional, Vasilopoulou, Theodora, additional, Vila, rafael, additional, Waterhouse, John, additional, Wimmer, Christian, additional, Wünderlich, Dirk, additional, Zohar, andrej, additional, Terranova, Nicholas, additional, and Sanchis, Lucia, additional

Published
2024
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32. Diagnostic weight functions in constants-of-motion phase-space

Author

Larsen, Mads Rud, primary, Moseev, Dmitry, additional, Jaulmes, Fabien, additional, Bogar, Klara, additional, Eriksson, Jacob, additional, Järleblad, Henrik, additional, Nocente, Massimo, additional, Prechel, Garrett, additional, Reman, Bernard C G, additional, Simmendefeldt, B, additional, Snicker, Antti, additional, Stagner, Luke, additional, Valentini, Andrea, additional, and Salewski, Mirko, additional

Published
2024
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33. Transport and acceleration mechanism of fast ions during edge localized modes in ASDEX Upgrade

Author

J.F. Rivero-Rodríguez, J. Galdon-Quiroga, J. Domínguez-Palacios, M. García-Muñoz, D. Garcia-Vallejo, J. Gonzalez-Martin, K.G. McClements, L. Sanchís, K. Särkimäki, A. Snicker, Y. Todo, L. Velarde, E. Viezzer, and the ASDEX Upgrade Team

Subjects
fusion, tokamak, fast-ions, ELMs, MHD, Monte-Carlo, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Observations of enhanced fast-ion losses during edge localized modes (ELMs) have been reported in the ASDEX Upgrade tokamak, revealing losses above the injection energy. This suggests that fast ions can be accelerated and lost due to the ELMs. Recent analysis of the ELM-induced losses suggests that the fast ions are lost due to a resonant interaction with the electromagnetic perturbation during the ELM crash. The fast-ion transport and acceleration during ELMs is modelled using electromagnetic fields computed using the hybrid kinetic-MHD code MEGA, while fast-ion full orbits are tracked with the ASCOT code. Time-evolving 3D electromagnetic fields have been implemented in ASCOT to compute fast-ion orbits in the presence of fast MHD events such as ELMs. The simulations successfully reproduce a field-aligned pattern of the losses on the tokamak wall and the formation of an accelerated population in the lost fast-ion distribution, while they predict an accelerated population in the confined distribution. A parametric study of the fast-ion constants of motion suggests a resonant interaction between the fast-ions and the electromagnetic fields arising during the ELM crash. In the case of fast-ion acceleration, the perpendicular electric perturbation, with scales smaller than the fast-ion gyroradius, breaks magnetic moment conservation and resonantly modifies the fast-ion energy.

Published
2023
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34. Modelling of energetic particle drive and damping effects on TAEs in AUG experiment with ECCD

Author

R. Calado, F. Nabais, S.E. Sharapov, P. Schneider, Ye. Kazakov, M. Garcia-Muñoz, A. Snicker, J. Ferreira, R. Coelho, M. Dreval, J. Fuertes, J. Galdon-Quiroga, J. Gonzalez-Martin, A. Karpushov, J. Stober, G. Tardini, M.A. Van Zeeland, and the ASDEX Upgrade Team

Subjects
tokamaks, Alfvén eigenmodes, energetic ions, ECCD, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The impact of electron cyclotron current drive (ECCD)-driven current on toroidicity-induced Alfvén eigenmodes (TAEs) in experiments on the AUG tokamak is investigated numerically. The dynamical evolution of the plasma profiles and equilibria are modelled with European transport solver, while ion cyclotron resonance heating-accelerated H-minority ions exciting TAEs are assessed with the PION code. TAEs, their drive and damping are computed with the codes CASTOR and CASTOR-K. In the set of discharges analysed, two groups of TAEs are observed, differing in frequency and radial location. Experimental observations show that when counter-ECCD is applied the higher frequency group of approximately 150 kHz is suppressed, while the lower frequency modes of 125 kHz are amplified. When co-ECCD is applied, depending on the location of the ECCD current deposition layer, both groups of TAE can be suppressed. Numerical calculations of energetic particle drive and thermal plasma damping show that neither one effect could explain the variety of the experimental observations. The fine balance between the drive, sensitive to the TAE position, and the radiative and continuum damping effects could only explain the experiment if the effects are considered all together.

Published
2023
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35. 4D and 5D phase-space tomography using slowing-down physics regularization

Author

B.S. Schmidt, M. Salewski, D. Moseev, M. Baquero-Ruiz, P.C. Hansen, J. Eriksson, O. Ford, G. Gorini, H. Järleblad, Ye O. Kazakov, D. Kulla, S. Lazerson, J.E. Mencke, D. Mykytchuk, M. Nocente, P. Poloskei, M. Rud, A. Snicker, L. Stagner, S. Äkäslompolo, and the W7-X Team

Subjects
fast ions, tomography, slowing-down, NBI, Tokamak, stellarator, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

We compute reconstructions of 4D and 5D fast-ion phase-space distribution functions in fusion plasmas from synthetic projections of these functions. The fast-ion phase-space distribution functions originating from neutral beam injection (NBI) at TCV and Wendelstein 7-X (W7-X) at full, half, and one-third injection energies can be distinguished and particle densities of each component inferred based on 20 synthetic spectra of projected velocities at TCV and 680 at W7-X. Further, we demonstrate that an expansion into a basis of slowing-down distribution functions is equivalent to regularization using slowing-down physics as prior information. Using this technique in a Tikhonov formulation, we infer the particle density fractions for each NBI energy for each NBI beam from synthetic measurements, resulting in six unknowns at TCV and 24 unknowns at W7-X. Additionally, we show that installing 40 LOS in each of 17 ports at W7-X, providing full beam coverage and almost full angle coverage, produces the highest quality reconstructions.

Published
2023
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36. 4D and 5D phase-space tomography using slowing-down physics regularization

Author

Schmidt, B, Salewski, M, Moseev, D, Baquero-Ruiz, M, Hansen, P, Eriksson, J, Ford, O, Gorini, G, Jarleblad, H, Kazakov, Y, Kulla, D, Lazerson, S, Mencke, J, Mykytchuk, D, Nocente, M, Poloskei, P, Rud, M, Snicker, A, Stagner, L, Akaslompolo, S, Schmidt B. S., Salewski M., Moseev D., Baquero-Ruiz M., Hansen P. C., Eriksson J., Ford O., Gorini G., Jarleblad H., Kazakov Y. O., Kulla D., Lazerson S., Mencke J. E., Mykytchuk D., Nocente M., Poloskei P., Rud M., Snicker A., Stagner L., Akaslompolo S., Schmidt, B, Salewski, M, Moseev, D, Baquero-Ruiz, M, Hansen, P, Eriksson, J, Ford, O, Gorini, G, Jarleblad, H, Kazakov, Y, Kulla, D, Lazerson, S, Mencke, J, Mykytchuk, D, Nocente, M, Poloskei, P, Rud, M, Snicker, A, Stagner, L, Akaslompolo, S, Schmidt B. S., Salewski M., Moseev D., Baquero-Ruiz M., Hansen P. C., Eriksson J., Ford O., Gorini G., Jarleblad H., Kazakov Y. O., Kulla D., Lazerson S., Mencke J. E., Mykytchuk D., Nocente M., Poloskei P., Rud M., Snicker A., Stagner L., and Akaslompolo S.

Abstract

We compute reconstructions of 4D and 5D fast-ion phase-space distribution functions in fusion plasmas from synthetic projections of these functions. The fast-ion phase-space distribution functions originating from neutral beam injection (NBI) at TCV and Wendelstein 7-X (W7-X) at full, half, and one-third injection energies can be distinguished and particle densities of each component inferred based on 20 synthetic spectra of projected velocities at TCV and 680 at W7-X. Further, we demonstrate that an expansion into a basis of slowing-down distribution functions is equivalent to regularization using slowing-down physics as prior information. Using this technique in a Tikhonov formulation, we infer the particle density fractions for each NBI energy for each NBI beam from synthetic measurements, resulting in six unknowns at TCV and 24 unknowns at W7-X. Additionally, we show that installing 40 LOS in each of 17 ports at W7-X, providing full beam coverage and almost full angle coverage, produces the highest quality reconstructions.

Published
2023

37. ASCOT: solving the kinetic equation of minority particle species in tokamak plasmas

Author

Hirvijoki, Eero, Asunta, Otto, Koskela, Tuomas, Kurki-Suonio, Taina, Miettunen, Juho, Sipilä, Seppo, Snicker, Antti, and Äkäslompolo, Simppa

Subjects
Physics - Plasma Physics
Abstract

A comprehensive description of methods, suitable for solving the kinetic equation for fast ions and impurity species in tokamak plasmas using Monte Carlo approach, is presented. The described methods include Hamiltonian orbit-following in particle and guiding center phase space, test particle or guiding center solution of the kinetic equation applying stochastic differential equations in the presence of Coulomb collisions, neoclassical tearing modes and Alfv\'en eigenmodes as electromagnetic perturbations relevant to fast ions, together with plasma flow and atomic reactions relevant to impurity studies. Applying the methods, a complete reimplementation of the well-established minority species code ASCOT is carried out as a response both to the increase in computing power during the last twenty years and to the weakly structured growth of the code, which has made implementation of additional models impractical. Also, a benchmark between the previous code and the reimplementation is accomplished, showing good agreement between the codes., Comment: 13 pages, 9 figures, submitted to Computer Physics Communications

Published
2013
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38. Monte Carlo implementation of a guiding-center Fokker-Planck kinetic equation

Author

Hirvijoki, Eero, Brizard, Alain, Snicker, Antti, and Kurki-Suonio, Taina

Subjects
Physics - Plasma Physics
Abstract

A Monte Carlo method for the collisional guiding-center Fokker-Planck kinetic equation is derived to include the effects of background magnetic-field nonuniformity. It is shown that, in the limit of a homogeneous magnetic field, the guiding-center Monte Carlo collision operators reduce to the standard Coulomb operators. The coefficients required for the implementation of the method are also given., Comment: 17 pages

Published
2013
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40. ASCOT: Solving the kinetic equation of minority particle species in tokamak plasmas

Author

Hirvijoki, E, Asunta, O, Koskela, T, Kurki-Suonio, T, Miettunen, J, Sipilä, S, Snicker, A, and Äkäslompolo, S

Subjects
Orbit-following, Impurity tracing, Monte Carlo, Fast ions, physics.plasm-ph, Nuclear & Particles Physics, Mathematical Sciences, Physical Sciences, Information and Computing Sciences
Abstract

A comprehensive description of methods, suitable for solving the kinetic equation for fast ions and impurity species in tokamak plasmas using a Monte Carlo approach, is presented. The described methods include Hamiltonian orbit-following in particle and guiding center phase space, test particle or guiding center solution of the kinetic equation applying stochastic differential equations in the presence of Coulomb collisions, neoclassical tearing modes and Alfvén eigenmodes as electromagnetic perturbations relevant to fast ions, together with plasma flow and atomic reactions relevant to impurity studies. Applying the methods, a complete reimplementation of the well-established minority species code ASCOT is carried out as a response both to the increase in computing power during the last twenty years and to the weakly structured growth of the code, which has made implementation of additional models impractical. Also, a benchmark between the previous code and the reimplementation is accomplished, showing good agreement between the codes. © 2014 Elsevier B.V. All rights reserved.

Published
2014

41. TORBEAM 2.0, a paraxial beam tracing code for electron-cyclotron beams in fusion plasmas for extended physics applications

Author

Poli, E., Bock, A., Lochbrunner, M., Maj, O., Reich, M., Snicker, A., Stegmeir, A., Volpe, F., Bertelli, N., Bilato, R., Conway, G.D., Farina, D., Felici, F., Figini, L., Fischer, R., Galperti, C., Happel, T., Lin-Liu, Y.R., Marushchenko, N.B., Mszanowski, U., Poli, F.M., Stober, J., Westerhof, E., Zille, R., Peeters, A.G., and Pereverzev, G.V.

Published
2018
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44. Simulations of fast ion wall loads in ASDEX upgrade in the presence of magnetic perturbations due to ELM-mitigation coils

Author

Asunta, O, Äkäslompolo, S, Kurki-Suonio, T, Koskela, T, Sipilä, S, Snicker, A, and García-Muñoz, M

Subjects
physics.plasm-ph, physics.comp-ph, Fluids & Plasmas, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The effect of ASDEX Upgrade (AUG) edge localized mode (ELM)-mitigation coils on fast ion wall loads was studied with the fast particle following Monte Carlo code ASCOT. Neutral beam injected particles were simulated in two AUG discharges both in the presence and in the absence of the magnetic field perturbation induced by the eight newly installed in-vessel coils. In one of the discharges (#26476) beams were applied individually, making it a useful basis for investigating the effect of the coils on different beams. However, no ELM mitigation was observed in #26476, probably due to the low plasma density. Therefore, another discharge (#26895) demonstrating clear ELM mitigation was also studied. The magnetic perturbation due to the in-vessel coils has a significant effect on the fast particle confinement, but only when total magnetic field, B tot, is low. When B tot was high, the perturbation did not increase the losses, but merely resulted in redistribution of the wall power loads. Hence, it seems to be possible to achieve ELM mitigation using in-vessel coils, while still avoiding increased fast ion losses, by simply using a strong B tot. Preliminary comparisons between simulated and experimental fast ion lost detector signals show a reasonable correspondence. © 2012 IAEA, Vienna.

Published
2012

45. Transport and acceleration mechanism of fast ions during edge localized modes in ASDEX Upgrade

Author

Rivero-Rodríguez, J.F., primary, Galdon-Quiroga, J., additional, Domínguez-Palacios, J., additional, García-Muñoz, M., additional, Garcia-Vallejo, D., additional, Gonzalez-Martin, J., additional, McClements, K.G., additional, Sanchís, L., additional, Särkimäki, K., additional, Snicker, A., additional, Todo, Y., additional, Velarde, L., additional, and Viezzer, E., additional

Published
2023
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46. 4D and 5D phase-space tomography using slowing-down physics regularization

Author

W7-X Team, Schmidt, B. S., Salewski, M., Moseev, D., Baquero-Ruiz, M., Hansen, P. C., Eriksson, J., Ford, O., Gorini, G., Järleblad, H., Kazakov, Ye O., Kulla, D., Lazerson, S., Mencke, J. E., Mykytchuk, D., Nocente, M., Poloskei, P., Rud, M., Snicker, A., Stagner, L., Äkäslompolo, S., W7-X Team, Max Planck Institute for Plasma Physics, Max Planck Society, Technical University of Denmark, Max-Planck-Institut für Plasmaphysik, Swiss Federal Institute of Technology Lausanne, Uppsala University, University of Milan - Bicocca, Royal Military Academy, Department of Applied Physics, General Atomics, Aalto-yliopisto, and Aalto University

Subjects
Technology, Nuclear and High Energy Physics, Tokamak, Atom and Molecular Physics and Optics, NBI, tomography, Condensed Matter Physics, Fusion, Plasma and Space Physics, slowing-down, Fusion, plasma och rymdfysik, stellarator, Atom- och molekylfysik och optik, fast ions, ddc:600, Den kondenserade materiens fysik
Abstract

Funding Information: This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them. Further, the assistance provided by Friedemann Herold was greatly appreciated. Publisher Copyright: © 2023 The Author(s). Published on behalf of IAEA by IOP Publishing Ltd. We compute reconstructions of 4D and 5D fast-ion phase-space distribution functions in fusion plasmas from synthetic projections of these functions. The fast-ion phase-space distribution functions originating from neutral beam injection (NBI) at TCV and Wendelstein 7-X (W7-X) at full, half, and one-third injection energies can be distinguished and particle densities of each component inferred based on 20 synthetic spectra of projected velocities at TCV and 680 at W7-X. Further, we demonstrate that an expansion into a basis of slowing-down distribution functions is equivalent to regularization using slowing-down physics as prior information. Using this technique in a Tikhonov formulation, we infer the particle density fractions for each NBI energy for each NBI beam from synthetic measurements, resulting in six unknowns at TCV and 24 unknowns at W7-X. Additionally, we show that installing 40 LOS in each of 17 ports at W7-X, providing full beam coverage and almost full angle coverage, produces the highest quality reconstructions.

Published
2023
Full Text
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47. Overview of the TCV tokamak experimental programme

Author

Reimerdes, H, Agostini, M, Alessi, E, Alberti, S, Andrebe, Y, Arnichand, H, Balbin, J, Bagnato, F, Baquero-Ruiz, M, Bernert, M, Bin, W, Blanchard, P, Blanken, T, Boedo, J, Brida, D, Brunner, S, Bogar, C, Bogar, O, Bolzonella, T, Bombarda, F, Bouquey, F, Bowman, C, Brunetti, D, Buermans, J, Bufferand, H, Calacci, L, Camenen, Y, Carli, S, Carnevale, D, Carpanese, F, Causa, F, Cavalier, J, Cavedon, M, Cazabonne, J, Cerovsky, J, Chandra, R, Chandrarajan Jayalekshmi, A, Chellai, O, Chmielewski, P, Choi, D, Ciraolo, G, Classen, I, Coda, S, Colandrea, C, Dal Molin, A, David, P, De Baar, M, Decker, J, Dekeyser, W, De Oliveira, H, Douai, D, Dreval, M, Dunne, M, Duval, B, Elmore, S, Embreus, O, Eriksson, F, Faitsch, M, Falchetto, G, Farnik, M, Fasoli, A, Fedorczak, N, Felici, F, Fevrier, O, Ficker, O, Fil, A, Fontana, M, Fransson, E, Frassinetti, L, Furno, I, Gahle, D, Galassi, D, Galazka, K, Galperti, C, Garavaglia, S, Garcia-Munoz, M, Geiger, B, Giacomin, M, Giruzzi, G, Gobbin, M, Golfinopoulos, T, Goodman, T, Gorno, S, Granucci, G, Graves, J, Griener, M, Gruca, M, Gyergyek, T, Haelterman, R, Hakola, A, Han, W, Happel, T, Harrer, G, Harrison, J, Henderson, S, Hogeweij, G, Hogge, J, Hoppe, M, Horacek, J, Huang, Z, Iantchenko, A, Innocente, P, Insulander Bjork, K, Ionita-Schrittweiser, C, Isliker, H, Jardin, A, Jaspers, R, Karimov, R, Karpushov, A, Kazakov, Y, Komm, M, Kong, M, Kovacic, J, Krutkin, O, Kudlacek, O, Kumar, U, Kwiatkowski, R, Labit, B, Laguardia, L, Lammers, J, Laribi, E, Laszynska, E, Lazaros, A, Linder, O, Linehan, B, Lipschultz, B, Llobet, X, Loizu, J, Lunt, T, Macusova, E, Marandet, Y, Maraschek, M, Marceca, G, Marchetto, C, Marchioni, S, Marmar, E, Martin, Y, Martinelli, L, Matos, F, Maurizio, R, Mayoral, M, Mazon, D, Menkovski, V, Merle, A, Merlo, G, Meyer, H, Mikszuta-Michalik, K, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Muhammed, H, Myatra, O, Mykytchuk, D, Napoli, F, Nem, R, Nielsen, A, Nocente, M, Nowak, S, Offeddu, N, Olsen, J, Orsitto, F, Pan, O, Papp, G, Pau, A, Perek, A, Pesamosca, F, Peysson, Y, Pigatto, L, Piron, C, Poradzinski, M, Porte, L, Putterich, T, Rabinski, M, Raj, H, Rasmussen, J, Ratta, G, Ravensbergen, T, Ricci, D, Ricci, P, Rispoli, N, Riva, F, Rivero-Rodriguez, J, Salewski, M, Sauter, O, Schmidt, B, Schrittweiser, R, Sharapov, S, Sheikh, U, Sieglin, B, Silva, M, Smolders, A, Snicker, A, Sozzi, C, Spolaore, M, Stagni, A, Stipani, L, Sun, G, Tala, T, Tamain, P, Tanaka, K, Tema Biwole, A, Terranova, D, Terry, J, Testa, D, Theiler, C, Thornton, A, Thrysoe, A, Torreblanca, H, Tsui, C, Vaccaro, D, Vallar, M, Van Berkel, M, Van Eester, D, Van Kampen, R, Van Mulders, S, Verhaegh, K, Verhaeghe, T, Vianello, N, Villone, F, Viezzer, E, Vincent, B, Voitsekhovitch, I, Vu, N, Walkden, N, Wauters, T, Weisen, H, Wendler, N, Wensing, M, Widmer, F, Wiesen, S, Wischmeier, M, Wijkamp, T, Wunderlich, D, Wuthrich, C, Yanovskiy, V, Zebrowski, J, Reimerdes H., Agostini M., Alessi E., Alberti S., Andrebe Y., Arnichand H., Balbin J., Bagnato F., Baquero-Ruiz M., Bernert M., Bin W., Blanchard P., Blanken T. C., Boedo J. A., Brida D., Brunner S., Bogar C., Bogar O., Bolzonella T., Bombarda F., Bouquey F., Bowman C., Brunetti D., Buermans J., Bufferand H., Calacci L., Camenen Y., Carli S., Carnevale D., Carpanese F., Causa F., Cavalier J., Cavedon M., Cazabonne J. A., Cerovsky J., Chandra R., Chandrarajan Jayalekshmi A., Chellai O., Chmielewski P., Choi D., Ciraolo G., Classen I. G. J., Coda S., Colandrea C., Dal Molin A., David P., De Baar M. R., Decker J., Dekeyser W., De Oliveira H., Douai D., Dreval M., Dunne M. G., Duval B. P., Elmore S., Embreus O., Eriksson F., Faitsch M., Falchetto G., Farnik M., Fasoli A., Fedorczak N., Felici F., Fevrier O., Ficker O., Fil A., Fontana M., Fransson E., Frassinetti L., Furno I., Gahle D. S., Galassi D., Galazka K., Galperti C., Garavaglia S., Garcia-Munoz M., Geiger B., Giacomin M., Giruzzi G., Gobbin M., Golfinopoulos T., Goodman T., Gorno S., Granucci G., Graves J. P., Griener M., Gruca M., Gyergyek T., Haelterman R., Hakola A., Han W., Happel T., Harrer G., Harrison J. R., Henderson S., Hogeweij G. M. D., Hogge J. -P., Hoppe M., Horacek J., Huang Z., Iantchenko A., Innocente P., Insulander Bjork K., Ionita-Schrittweiser C., Isliker H., Jardin A., Jaspers R. J. E., Karimov R., Karpushov A. N., Kazakov Y., Komm M., Kong M., Kovacic J., Krutkin O., Kudlacek O., Kumar U., Kwiatkowski R., Labit B., Laguardia L., Lammers J. T., Laribi E., Laszynska E., Lazaros A., Linder O., Linehan B., Lipschultz B., Llobet X., Loizu J., Lunt T., Macusova E., Marandet Y., Maraschek M., Marceca G., Marchetto C., Marchioni S., Marmar E. S., Martin Y., Martinelli L., Matos F., Maurizio R., Mayoral M. -L., Mazon D., Menkovski V., Merle A., Merlo G., Meyer H., Mikszuta-Michalik K., Molina Cabrera P. A., Morales J., Moret J. -M., Moro A., Moulton D., Muhammed H., Myatra O., Mykytchuk D., Napoli F., Nem R. D., Nielsen A. H., Nocente M., Nowak S., Offeddu N., Olsen J., Orsitto F. P., Pan O., Papp G., Pau A., Perek A., Pesamosca F., Peysson Y., Pigatto L., Piron C., Poradzinski M., Porte L., Putterich T., Rabinski M., Raj H., Rasmussen J. J., Ratta G. A., Ravensbergen T., Ricci D., Ricci P., Rispoli N., Riva F., Rivero-Rodriguez J. F., Salewski M., Sauter O., Schmidt B. S., Schrittweiser R., Sharapov S., Sheikh U. A., Sieglin B., Silva M., Smolders A., Snicker A., Sozzi C., Spolaore M., Stagni A., Stipani L., Sun G., Tala T., Tamain P., Tanaka K., Tema Biwole A., Terranova D., Terry J. L., Testa D., Theiler C., Thornton A., Thrysoe A., Torreblanca H., Tsui C. K., Vaccaro D., Vallar M., Van Berkel M., Van Eester D., Van Kampen R. J. R., Van Mulders S., Verhaegh K., Verhaeghe T., Vianello N., Villone F., Viezzer E., Vincent B., Voitsekhovitch I., Vu N. M. T., Walkden N., Wauters T., Weisen H., Wendler N., Wensing M., Widmer F., Wiesen S., Wischmeier M., Wijkamp T. A., Wunderlich D., Wuthrich C., Yanovskiy V., Zebrowski J., Reimerdes, H, Agostini, M, Alessi, E, Alberti, S, Andrebe, Y, Arnichand, H, Balbin, J, Bagnato, F, Baquero-Ruiz, M, Bernert, M, Bin, W, Blanchard, P, Blanken, T, Boedo, J, Brida, D, Brunner, S, Bogar, C, Bogar, O, Bolzonella, T, Bombarda, F, Bouquey, F, Bowman, C, Brunetti, D, Buermans, J, Bufferand, H, Calacci, L, Camenen, Y, Carli, S, Carnevale, D, Carpanese, F, Causa, F, Cavalier, J, Cavedon, M, Cazabonne, J, Cerovsky, J, Chandra, R, Chandrarajan Jayalekshmi, A, Chellai, O, Chmielewski, P, Choi, D, Ciraolo, G, Classen, I, Coda, S, Colandrea, C, Dal Molin, A, David, P, De Baar, M, Decker, J, Dekeyser, W, De Oliveira, H, Douai, D, Dreval, M, Dunne, M, Duval, B, Elmore, S, Embreus, O, Eriksson, F, Faitsch, M, Falchetto, G, Farnik, M, Fasoli, A, Fedorczak, N, Felici, F, Fevrier, O, Ficker, O, Fil, A, Fontana, M, Fransson, E, Frassinetti, L, Furno, I, Gahle, D, Galassi, D, Galazka, K, Galperti, C, Garavaglia, S, Garcia-Munoz, M, Geiger, B, Giacomin, M, Giruzzi, G, Gobbin, M, Golfinopoulos, T, Goodman, T, Gorno, S, Granucci, G, Graves, J, Griener, M, Gruca, M, Gyergyek, T, Haelterman, R, Hakola, A, Han, W, Happel, T, Harrer, G, Harrison, J, Henderson, S, Hogeweij, G, Hogge, J, Hoppe, M, Horacek, J, Huang, Z, Iantchenko, A, Innocente, P, Insulander Bjork, K, Ionita-Schrittweiser, C, Isliker, H, Jardin, A, Jaspers, R, Karimov, R, Karpushov, A, Kazakov, Y, Komm, M, Kong, M, Kovacic, J, Krutkin, O, Kudlacek, O, Kumar, U, Kwiatkowski, R, Labit, B, Laguardia, L, Lammers, J, Laribi, E, Laszynska, E, Lazaros, A, Linder, O, Linehan, B, Lipschultz, B, Llobet, X, Loizu, J, Lunt, T, Macusova, E, Marandet, Y, Maraschek, M, Marceca, G, Marchetto, C, Marchioni, S, Marmar, E, Martin, Y, Martinelli, L, Matos, F, Maurizio, R, Mayoral, M, Mazon, D, Menkovski, V, Merle, A, Merlo, G, Meyer, H, Mikszuta-Michalik, K, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Muhammed, H, Myatra, O, Mykytchuk, D, Napoli, F, Nem, R, Nielsen, A, Nocente, M, Nowak, S, Offeddu, N, Olsen, J, Orsitto, F, Pan, O, Papp, G, Pau, A, Perek, A, Pesamosca, F, Peysson, Y, Pigatto, L, Piron, C, Poradzinski, M, Porte, L, Putterich, T, Rabinski, M, Raj, H, Rasmussen, J, Ratta, G, Ravensbergen, T, Ricci, D, Ricci, P, Rispoli, N, Riva, F, Rivero-Rodriguez, J, Salewski, M, Sauter, O, Schmidt, B, Schrittweiser, R, Sharapov, S, Sheikh, U, Sieglin, B, Silva, M, Smolders, A, Snicker, A, Sozzi, C, Spolaore, M, Stagni, A, Stipani, L, Sun, G, Tala, T, Tamain, P, Tanaka, K, Tema Biwole, A, Terranova, D, Terry, J, Testa, D, Theiler, C, Thornton, A, Thrysoe, A, Torreblanca, H, Tsui, C, Vaccaro, D, Vallar, M, Van Berkel, M, Van Eester, D, Van Kampen, R, Van Mulders, S, Verhaegh, K, Verhaeghe, T, Vianello, N, Villone, F, Viezzer, E, Vincent, B, Voitsekhovitch, I, Vu, N, Walkden, N, Wauters, T, Weisen, H, Wendler, N, Wensing, M, Widmer, F, Wiesen, S, Wischmeier, M, Wijkamp, T, Wunderlich, D, Wuthrich, C, Yanovskiy, V, Zebrowski, J, Reimerdes H., Agostini M., Alessi E., Alberti S., Andrebe Y., Arnichand H., Balbin J., Bagnato F., Baquero-Ruiz M., Bernert M., Bin W., Blanchard P., Blanken T. C., Boedo J. A., Brida D., Brunner S., Bogar C., Bogar O., Bolzonella T., Bombarda F., Bouquey F., Bowman C., Brunetti D., Buermans J., Bufferand H., Calacci L., Camenen Y., Carli S., Carnevale D., Carpanese F., Causa F., Cavalier J., Cavedon M., Cazabonne J. A., Cerovsky J., Chandra R., Chandrarajan Jayalekshmi A., Chellai O., Chmielewski P., Choi D., Ciraolo G., Classen I. G. J., Coda S., Colandrea C., Dal Molin A., David P., De Baar M. R., Decker J., Dekeyser W., De Oliveira H., Douai D., Dreval M., Dunne M. G., Duval B. P., Elmore S., Embreus O., Eriksson F., Faitsch M., Falchetto G., Farnik M., Fasoli A., Fedorczak N., Felici F., Fevrier O., Ficker O., Fil A., Fontana M., Fransson E., Frassinetti L., Furno I., Gahle D. S., Galassi D., Galazka K., Galperti C., Garavaglia S., Garcia-Munoz M., Geiger B., Giacomin M., Giruzzi G., Gobbin M., Golfinopoulos T., Goodman T., Gorno S., Granucci G., Graves J. P., Griener M., Gruca M., Gyergyek T., Haelterman R., Hakola A., Han W., Happel T., Harrer G., Harrison J. R., Henderson S., Hogeweij G. M. D., Hogge J. -P., Hoppe M., Horacek J., Huang Z., Iantchenko A., Innocente P., Insulander Bjork K., Ionita-Schrittweiser C., Isliker H., Jardin A., Jaspers R. J. E., Karimov R., Karpushov A. N., Kazakov Y., Komm M., Kong M., Kovacic J., Krutkin O., Kudlacek O., Kumar U., Kwiatkowski R., Labit B., Laguardia L., Lammers J. T., Laribi E., Laszynska E., Lazaros A., Linder O., Linehan B., Lipschultz B., Llobet X., Loizu J., Lunt T., Macusova E., Marandet Y., Maraschek M., Marceca G., Marchetto C., Marchioni S., Marmar E. S., Martin Y., Martinelli L., Matos F., Maurizio R., Mayoral M. -L., Mazon D., Menkovski V., Merle A., Merlo G., Meyer H., Mikszuta-Michalik K., Molina Cabrera P. A., Morales J., Moret J. -M., Moro A., Moulton D., Muhammed H., Myatra O., Mykytchuk D., Napoli F., Nem R. D., Nielsen A. H., Nocente M., Nowak S., Offeddu N., Olsen J., Orsitto F. P., Pan O., Papp G., Pau A., Perek A., Pesamosca F., Peysson Y., Pigatto L., Piron C., Poradzinski M., Porte L., Putterich T., Rabinski M., Raj H., Rasmussen J. J., Ratta G. A., Ravensbergen T., Ricci D., Ricci P., Rispoli N., Riva F., Rivero-Rodriguez J. F., Salewski M., Sauter O., Schmidt B. S., Schrittweiser R., Sharapov S., Sheikh U. A., Sieglin B., Silva M., Smolders A., Snicker A., Sozzi C., Spolaore M., Stagni A., Stipani L., Sun G., Tala T., Tamain P., Tanaka K., Tema Biwole A., Terranova D., Terry J. L., Testa D., Theiler C., Thornton A., Thrysoe A., Torreblanca H., Tsui C. K., Vaccaro D., Vallar M., Van Berkel M., Van Eester D., Van Kampen R. J. R., Van Mulders S., Verhaegh K., Verhaeghe T., Vianello N., Villone F., Viezzer E., Vincent B., Voitsekhovitch I., Vu N. M. T., Walkden N., Wauters T., Weisen H., Wendler N., Wensing M., Widmer F., Wiesen S., Wischmeier M., Wijkamp T. A., Wunderlich D., Wuthrich C., Yanovskiy V., and Zebrowski J.

Abstract

The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include Te/Ti ∼1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with 'small' (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019-20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.

Published
2022

48. 4D and 5D phase-space tomography using slowing-down physics regularization

Author

Schmidt, Bo Simmendefeldt, primary, Salewski, Mirko, additional, Moseev, Dmitry, additional, Baquero-Ruiz, Marcelo, additional, Hansen, Per Christian, additional, Eriksson, Jacob, additional, Ford, Oliver P, additional, Gorini, Giuseppe, additional, Järleblad, Henrik, additional, Kazakov, Yevgen, additional, Kulla, David, additional, Lazerson, Samuel A, additional, Mencke, Jacob, additional, Mykytchuk, Dmytry, additional, Nocente, Massimo, additional, Poloskei, Peter Zsolt, additional, Larsen, Mads Rud, additional, Snicker, Antti, additional, Stagner, Luke, additional, and Äkäslompolo, Simppa Johannes, additional

Published
2023
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49. Predictive simulations for plasma scenarios in the SMART tokamak

Author

Universidad de Sevilla. Departamento de Ingeniería Energética, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla. Departamento de Física Aplicada III, Universidad de Sevilla. FQM402: Ciencias y Tecnologías del Plasma y el Espacio, Fondo Europeo de Desarollo Regional (FEDER) by the European Commission under grant agreement number IE17-5670, Fondo Europeo de Desarollo Regional (FEDER) by the European Commission under grant agreement number US-15570, European Union’s Horizon 2020 research and innovation programme grant agreement No. 805162, Mancini, Alessio, Velarde Gallardo, Lina, Viezzer, Eleonora, Cruz Zabala, Diego José, Rivero Rodríguez, Juan Francisco, García Muñoz, Manuel, Sanchís Sánchez, Lucía, Snicker, Antti, García Domínguez, J., Segado Fernández, Jorge, Hidalgo Salaverri, Javier, Cano Megías, Pilar, Toscano Jiménez, Manuel, Universidad de Sevilla. Departamento de Ingeniería Energética, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla. Departamento de Física Aplicada III, Universidad de Sevilla. FQM402: Ciencias y Tecnologías del Plasma y el Espacio, Fondo Europeo de Desarollo Regional (FEDER) by the European Commission under grant agreement number IE17-5670, Fondo Europeo de Desarollo Regional (FEDER) by the European Commission under grant agreement number US-15570, European Union’s Horizon 2020 research and innovation programme grant agreement No. 805162, Mancini, Alessio, Velarde Gallardo, Lina, Viezzer, Eleonora, Cruz Zabala, Diego José, Rivero Rodríguez, Juan Francisco, García Muñoz, Manuel, Sanchís Sánchez, Lucía, Snicker, Antti, García Domínguez, J., Segado Fernández, Jorge, Hidalgo Salaverri, Javier, Cano Megías, Pilar, and Toscano Jiménez, Manuel

Published
2023

50. 4D and 5D phase-space tomography using slowing-down physics regularization

Author

Schmidt, B. S., Salewski, M., Moseev, D., Baquero-Ruiz, M., Hansen, P. C., Eriksson, Jacob, Ford, O., Gorini, G., Järleblad, H. O., Kazakov, Ye, Kulla, D., Lazerson, S., Mencke, J. E., Mykytchuk, D., Nocente, M., Poloskei, P., Rud, M., Snicker, A., Stagner, L., Äkäslompolo, S., Schmidt, B. S., Salewski, M., Moseev, D., Baquero-Ruiz, M., Hansen, P. C., Eriksson, Jacob, Ford, O., Gorini, G., Järleblad, H. O., Kazakov, Ye, Kulla, D., Lazerson, S., Mencke, J. E., Mykytchuk, D., Nocente, M., Poloskei, P., Rud, M., Snicker, A., Stagner, L., and Äkäslompolo, S.

Abstract

We compute reconstructions of 4D and 5D fast-ion phase-space distribution functions in fusion plasmas from synthetic projections of these functions. The fast-ion phase-space distribution functions originating from neutral beam injection (NBI) at TCV and Wendelstein 7-X (W7-X) at full, half, and one-third injection energies can be distinguished and particle densities of each component inferred based on 20 synthetic spectra of projected velocities at TCV and 680 at W7-X. Further, we demonstrate that an expansion into a basis of slowing-down distribution functions is equivalent to regularization using slowing-down physics as prior information. Using this technique in a Tikhonov formulation, we infer the particle density fractions for each NBI energy for each NBI beam from synthetic measurements, resulting in six unknowns at TCV and 24 unknowns at W7-X. Additionally, we show that installing 40 LOS in each of 17 ports at W7-X, providing full beam coverage and almost full angle coverage, produces the highest quality reconstructions.

Published
2023
Full Text
View/download PDF

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