Experimental and CFD analyses of a thermal radiation shield dimple plate for cryogenic pump application

Large customized cryogenic pumps are used in fusion reactors to evacuate the plasma exhaust from the torus. Cryopumps usually consist of an active pumping surface area cooled below 5 K and shielded from direct outer thermal radiation by plates cooled at 80K. In nuclear fusion applications, cryopumps are exposed to excessively high heat fluxes during pumping operation, and follow-up regeneration cycles with rapid warm-up and cool-down phases. Therefore, high cryogenic operational mass flows are required and thus pressure drop and heat transfer characteristics become key issues for the design of the pump cryogenic circuits. Actively cooled dimple plates are a preferred design solution for the thermal radiation shield. A test plate with a rhomb pattern of dimples has been manufactured and tested in terms of pressure drop with a dedicated test facility using water. In the present work, computational fluid dynamics (CFD) models of the test dimple plate have been performed, and computed pressure drops have been compared to experimental results. Despite the complexity of the geometry, a good agreement with the experimental results was found. Then, the validated CFD approach has been further extended to relevant operation conditions, using gaseous helium at cryogenic temperature as working fluid. The resulting pressure drop and heat transfer characteristics are finally presented

Physics and operation oriented activities in preparation of the JT-60SA tokamak exploitation

none76noneGiruzzi, G.; Joffrin, E.; Garcia, J.; Douai, D.; Artaud, J. -F.; Pégourié, B.; Maget, P.; Kamada, Y.; Yoshida, M.; Ide, S.; Hayashi, N.; Matsunaga, G.; Nakano, T.; Shinohara, K.; Sakurai, S.; Suzuki, T.; Urano, H.; Enoeda, M.; Kubo, H.; Kamiya, K.; Takechi, M.; Miyata, Y.; Isayama, A.; Kobayashi, T.; Moriyama, S.; Shimizu, K.; Hoshino, K.; Kawashima, H.; Bierwage, A.; Mcdonald, D.; Sozzi, C.; Figini, L.; Nowak, S.; Moro, A.; Platania, P.; Ricci, D.; Granucci, G.; Bolzonella, T.; Bettini, P.; Innocente, P.; Terranova, D.; Pigatto, L.; Villone, F.; Pironti, A.; Mastrostefano, S.; De Tommasi, G.; Mattei, M.; Mele, A.; Orsitto, F.; Dunai, D.; Szepesi, T.; Barbato, E.; Vitale, V.; Romanelli, M.; Garzotti, L.; Boboc, A.; Saarelma, S.; Wischmeier, M.; Lauber, P.; Lang, P.; Neu, R.; Day, C.; Gleason-Gonzalez, C.; Scannapiego, M.; Zagorski, R.; Galazaka, K.; Stepniewski, W.; Cruz, N.; De La Luna, E.; Farcia-Munoz, M.; Vega, J.; Clement-Lorenzo, S.; Sartori, F.; Coda, S.; Goodman, T.; Soare, S.Giruzzi, Gerardo; Joffrin, E.; Garcia, J.; Douai, D.; Artaud, J. F.; Pégourié, B.; Maget, P.; Kamada, Y.; Yoshida, M.; Ide, S.; Hayashi, N.; Matsunaga, G.; Nakano, T.; Shinohara, K.; Sakurai, S.; Suzuki, T.; Urano, H.; Enoeda, M.; Kubo, Hiroshi; Kamiya, K.; Takechi, M.; Miyata, Y.; Isayama, A.; Kobayashi, T.; Moriyama, S.; Shimizu, K.; Hoshino, K.; Kawashima, H.; Bierwage, A.; Mcdonald, D.; Sozzi, C.; Figini, L.; Nowak, S.; Moro, A.; Platania, P.; Ricci, Daniele; Granucci, G.; Bolzonella, Tommaso; Bettini, P.; Innocente, P.; Terranova, David; Pigatto, Leonardo; Villone, F.; Pironti, Alfredo; Mastrostefano, S.; De Tommasi, G.; Mattei, M.; Mele, Adriano; Orsitto, F.; Dunai, D.; Szepesi, T.; Barbato, E.; Vitale, V.; Romanelli, M.; Garzotti, L.; Boboc, A.; Saarelma, S.; Wischmeier, M.; Lauber, P.; Lang, P.; Neu, R.; Day, C.; Gleason Gonzalez, C.; Scannapiego, M.; Zagorski, R.; Galazaka, K.; Stepniewski, W.; Cruz, N.; De La Luna, E.; Farcia Munoz, M.; Vega, J.; Clement Lorenzo, S.; Sartori, F.; Coda, S.; Goodman, T.; Soare, S

Advances in the physics studies for the JT-60SA tokamak exploitation and research plan

JT-60SA, the largest tokamak that will operate before ITER, has been designed and built jointly by Japan and Europe, and is due to start operation in 2020. Its main missions are to support ITER exploitation and to contribute to the demonstration fusion reactor machine and scenario design. Peculiar properties of JT-60SA are its capability to produce long-pulse, high-), and highly shaped plasmas. The preparation of the JT-60SA Research Plan, plasma scenarios, and exploitation are producing physics results that are not only relevant to future JT-60SA experiments, but often constitute original contributions to plasma physics and fusion research. Results of this kind are presented in this paper, in particular in the areas of fast ion physics, high-beta plasma properties and control, and non-linear edge localised mode stability studies

Physics and operation oriented activities in preparation of the JT-60SA tokamak exploitation

The JT-60SA tokamak, being built under the Broader Approach agreement jointly by Europe and Japan, is due to start operation in 2020 and is expected to give substantial contributions to both ITER and DEMO scenario optimisation. A broad set of preparation activities for an efficient start of the experiments on JT-60SA is being carried out, involving elaboration of the Research Plan, advanced modelling in various domains, feasibility and conception studies of diagnostics and other sub-systems in connection with the priorities of the scientific programme, development and validation of operation tools. The logic and coherence of this approach, as well as the most significant results of the main activities undertaken are presented and summarised

Advances in the physics studies for the JT-60SA tokamak exploitation and research plan

International audienceJT-60SA, the largest tokamak that will operate before ITER, has been designed and built jointlyby Japan and Europe, and is due to start operation in 2020. Its main missions are to support ITERexploitation and to contribute to the demonstration fusion reactor machine and scenario design.Peculiar properties of JT-60SA are its capability to produce long-pulse, high-β,and highlyshaped plasmas. The preparation of the JT-60SA Research Plan, plasma scenarios, andexploitation are producing physics results that are not only relevant to future JT-60SAexperiments, but often constitute original contributions to plasma physics and fusion research.Results of this kind are presented in this paper, in particular in the areas of fast ion physics, high-beta plasma properties and control, and non-linear edge localised mode stability studies

Physics and operation oriented activities in preparation of the JT-60SA tokamak exploitation

The JT-60SA tokamak, being built under the Broader Approach agreement jointly by Europe and Japan, is due to start operation in 2020 and is expected to give substantial contributions to both ITER and DEMO scenario optimisation. A broad set of preparation activities for an efficient start of the experiments on JT-60SA is being carried out, involving elaboration of the Research Plan, advanced modelling in various domains, feasibility and conception studies of diagnostics and other sub-systems in connection with the priorities of the scientific programme, development and validation of operation tools. The logic and coherence of this approach, as well as the most significant results of the main activities undertaken are presented and summarised