Bin Zhu Nathanael Leung Winfried Kockelmann Saurabh Kabra Andrew J. London Michael Gorley Mark J. Whiting Yiqiang Wang Tan Sui
Eurofer97 steel is a primary structural material for the plasma facing-components of future fusion reactors. Laser welding is a promising technique that can overcome the challenges of remote handling and maintenance. However, the interaction of the induced residual stress distribution with the heterogeneous microstructure may degrade the mechanical…
Preprint PurchaseBin Zhu Yiqiang Wang Jiří Dluhoš Andy J. London Michael Gorley Mark J. Whiting Tan Sui
The plasma-facing components of future fusion reactors, where the Eurofer97 is the primary structural material, will be assembled by laser-welding techniques. The heterogeneous residual stress induced by welding can interact with the microstructure, resulting in a degradation of mechanical properties and a reduction in joint lifetime. Here, a Xe
Preprint PublishedH. Zhu R.O. Dendy S.C. Chapman S. Inagaki
It is known that rapid edge cooling of magnetically confined plasmas can trigger heat pulses that propagate rapidly inward. These can result in large excursion, either positive or negative, in the electron temperature at the core. A set of particularly detailed measurements was obtained in Large Helical Device(LHD) plasmas [S. Inagaki et al, Plasma…
Preprint PublishedH. Zhu S. C. Chapman R. O. Dendy K. Itoh
It is shown that rapid substantial changes in heating rate can induce transitions to improved energy confinement regimes in zero-dimensional models for tokamak plasma phenomenology. We examine for the first time the effect of step changes in heating rate in the models of Kim and Diamond [Phys. Rev. Lett. 90, 185006 (2003)] and Malkov and Diamond [P…
PublishedH. Zhu S. C. Chapman R. O. Dendy
Energy transport and confinement in tokamak fusion plasmas is usually determined by the coupled nonlinear interactions of small-scale drift turbulence and larger scale coherent nonlinear structures, such as zonal flows, together with free energy sources such as temperature gradients. Zero-dimensional models, designed to embody plausible physical na…
PublishedM. Okabayashi G. Matsunaga J.S. Degrassie W.W. Heidbrink Y. In Y.Q. Liu H. Reimerdes W.M. Solomon E.J. Strait M. Takechi N. Asakura R.V. Budny G.L. Jackson J.M. Hanson R. J. La Haye M.J. Lanctot J. Manickam K. Shinohara Y.B. Zhu
An energetic-particle (EP)-driven “off-axis-fishbone-like mode (OFM)” often triggers a resistive wall mode (RWM) in JT-60U and DIII-D devices, preventing long-duration high-b N discharges. In these experiments, the EPs are energetic ions (70–85 keV) injected by neutral beams to produce high-pressure plasmas. EP-driven bursting events reduce t…
PublishedM.A. Van Zeeland W.W. Heidbrink R.K. Fisher M. García Muñoz, G.J. Kramer D.C. Pace R.B. White S. Aekaeslompolo M.E. Austin J.E. Boom I.G.J. Classen S. Da Graça B. Geiger M. Gorelenkova N. N. Gorelenkov A. W. Hyatt N. Luhmann M. Maraschek G. R. McKee R. A. Moyer C. M. Muscatello R. Nazikian H. Park S. Sharapov W. Suttrop G. Tardini B. J. Tobias Y. B. Zhu DIII-D and ASDEX Upgrade Teams
Neutral beam injection into reversed magnetic shear DIII-D and ASDEX Upgrade plasmas produces a variety of Alfvénic activity including toroidicity-induced Alfvén eigenmodes and reversed shear Alfvén eigenmodes (RSAEs). These modes are studied during the discharge current ramp phase when incomplete current penetration results in a high central sa…
PublishedH. Reimerdes T. C. Hender S. A. Sabbagh J. M. Bialek M. S. Chu A. M. Garofalo M. P. Gryaznevich D. F. Howell G. L. Jackson R. J. La Haye Y. Q. Liu J. E. Menard G. A. Navratil M. Okabayashi S. D. Pinches A. C. Sontag E. J. Strait W. Zhu M
Dedicated experiments in the DIII-D tokamak J. L. Luxon, Nucl. Fusion, 42 , 614 2002, the Joint European Torus JET P. H. Rebut, R. J. Bickerton, and B. E. Keen, Nucl. Fusion 25 , 1011 1985, and the National Spherical Torus Experiment NSTX M. Ono, S. M. Kaye, Y.-K. M. Peng et al. , Nucl. Fusion 40 , 557 2000 reveal the commonalities of resistive wal…
Published