R.C. For tokamak plasmas this turbulence-induced transport is thought to be responsible for the observed anomalous transport, in particular, the electron thermal transport which is up to two orders of magnitude higher than theoretical predictions [, Experimentally, for investigating mechanisms of turbulent transport, the turbulence amplitudes in density, temperature, potential, magnetic fluctuations and associated transport have been measured in many fusion devices and some comparisons were also made among several tokamaks and stellarators [, 4.3. As proposed by Spitzer and Mercier [, The geometrical parameters also differ much for tokamaks and stellarators. The upside to … In a tokamak, the poloidal field is created by the toroidal plasma current, while in a stellarator both poloidal and toroidal fields are supplied by external currents. A further difference lies in the shape of the plasma cross-section. 5. R. Balescu, Transport Processes in Plasmas: Neoclassical Transport, Theory of plasma transport in toroidal confinement systems, Neoclassical transport of impurities in tokamak plasmas, The energy confinement time in stellarators”. Article copyright remains as specified within the article. Peer review under responsibility of Science and Technology Information Center, China Academy of Engineering Physics. Y. Feng, M. Kobayashi, T. Lunt, D. Reiter, Comparison between stellarator and tokamak divertor transport. 46. Y. Shimomura, M. Keilhacker, K. Lackner, H. Murmann. Equilibrium and stability of a toroidal magnetohydrodynamic system in the neighbourhood of a magnetic axis, A comparative study of transport in stellarators and tokamaks. Yoon, F.X. This description is found (together with a good explanation of drifts) in de Blank's article on guiding center motion. DIII-D tokamak. For the first time in history, the institute has offered six postdoc positions with the intention to create synergies between tokamak and stellarator research. Appel, D.V. Watanabe, M. Nunami, S. Nishimura, Quasisymmetric toroidal plasmas with large mean flows. 60. Inertial Confinement Fusion(ICF) relies on the rapid transfer of energy into a fuel target — usually a fuel pellet. Disruptions pose serious problems for tokamak development as they firstly limit the range of operation in current and density, and secondly lead to large mechanical stresses and intense heat loads to the plasma facing components of reactor devices. P.N. The Greifswald branch hosts the stellarator Wendelstein 7-X and the Garching institute operates the tokamak ASDEX Upgrade. Y. Kolesnichenko, A. Könies, V.V. 68. Kasilov, W. Kernbichler, Benchmarking of the mono-energetic transport coefficients-results from the International Collaboration on Neoclassical Transport in Stellarators (ICNTS). In the long mean-free-path regime fast ions in stellarators tend to drift radially and thus leave the confinement region. Altukhov, L.A. Esipov, The isotope effect in turbulent transport control by GAMs. More quantitative assessments rely nevertheless on the modelling using the EMC3-EIRENE code. By comparison, the more popular cousin to the stellarator, called a tokamak, is in wider use. L.C. N. Ohyabu, T. Watanabe, H. Ji, H. Akao, T. Ono, The large helical device (LHD) helical divertor. In principle, differences in the discharge characteristics and ICC efficiency may be expected between tokamak and stellarator. By continuing you agree to the use of cookies. T. Hayashi, T. Sato, P. Merkel, J. Nührenberg, U. Schwenn, Formation and ‘self- healing’ of magnetic islands in finite-β helias equilibria, Stability of bootstrap current-driven magnetic islands in stellarators. ITER won't generate electricity. M. Bessenrodt-Weberpals, F. Wagner, O. Gehre, L. Giannone, J.V. Retarding field analyzers for the ion temperature measurements in the SOL plasmas on the tokamak ISTTOK and the TJ-II stellarator Plasma device R, m a, m B, T Ip, kA x1019 m-3 Te(0), eV ISTTOK 0.45 0.085 0.5 3-5 0.3-0.6 120 TJ-II 1.5 0.22-0.25 1 0.2-1 600 Table 1. 84. Wendelstein 7-X fusion device produces its first hydrogen plasma, February 03, 2016. Kardaun, J.G. (Xu Y. W.A. Here, the required magnetic field is a bit easier to create than for a helix, but it's still far more complicated than for a tokamak. Because the impurities originated from plasma-facing components (PFC) present a lot of problems, Experimentally, discrepancies in divertor transport have also been observed between tokamaks and stellarators. Y. Kolesnichenko, A. Könies, V.V. H. Sugama, T.H. It is expected for ITER to generate 500 MW fusion power from ∼50 MW input for a period lasting a few minutes (∼400 s). maximum value of the magnetic field strength on the surface. 34. 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