D. Hancock T. Barrett J. Foster M. Fursdon G. Keech S. McIntosh W. Timmis M. Rieth J. Reiser
The design of a divertor target for DEMO remains one of the most challenging engineering tasks to be overcome on the path to fusion power. Under the European DEMO programme, a promising concept known as Thermal Break has been developed at CCFE. This concept is a variation of the ITER tungsten divertor in which the pure Copper interlayer between Cop…
Preprint PublishedT. Eade S. Lilley Z. Ghani E. Delmas
The requirement for maintenance in areas with relatively high shutdown dose rate fields is a key issue to address in the design and engineering of ITER, next generation devices and future commercial fusion reactors. In order to estimate the shutdown dose rate during maintenance and intervention scenarios CCFEs Mesh Coupled implementation of the R…
Preprint PublishedV. Parail G. Corrigan P. Da Silva Aresta Belo E. De La Luna D. Harting F. Koechl T. Koskela A. Meigs E. Militello-Asp M. Romanelli M. Tsalas JET-EFDA contributors
The influence of the ITER-like Wall (ILW) with divertor target plate made of tungsten (W), on plasma performance in JET H-mode is being investigated since 2011 (see [1] and references therein). One of the key issues in discharges with low level of D fuelling is observed accumulation of W in the plasma core, which leads to a reduction in plasma perf…
Preprint PublishedA. Xu C. Beck D. E. J. Armstrong K. Rajan G. D.W. Smith P. A. J. Bagot S. G. Roberts
This study examines clustering and hardening in W–2 at.% Re and W–1 at.% Re–1 at.% Os alloys induced by 2 MeV W + ion irradiation at 573 and 773 K. Such clusters are known precursors to the formation of embrittling precipitates, a potentially life-limiting phenomenon in the oper- ation of fusion reactor components. Increases in hardness were …
PublishedH. Tanabe T. Yamada T. Watanabe K. Gi K. Kadowaki M. Inomoto R. Imazawa M. Gryaznevich C. Michael B. Crowley N. J. Conway R. Scannell J. Harrison I. Fitzgerald A. Meakins N. Hawkes K. G. McClements T. OGorman C. Z. Cheng Y. Ono The MAST Team
Electron and ion heating characteristics during merging reconnection startup on the MAST spherical tokamak have been revealed in detail using 130 channel YAG- and 300 channel Ruby-Thomson scattering system and a new 32 chord ion Doppler tomography diagnostic. Detailed 2D profile measurements of electron and ion temperature together with electron de…
Preprint PublishedE. Lerche D. Van Eester Y. Kazakov P. Jacquet I. Monakhov M. Goniche L. Colas F. Rimini K. Crombé R. Dumont V. Kiptily M. Santala JET Contributors
Heating single ion species plasmas with ICRF is a challenging task: Fundamental ion cyclotron heating (w = w ci ) suffers from the adverse polarization of the RF electric fields near the majority cyclotron resonance while second harmonic heating (w = 2w ci ) typically requires pre-heating of the plasma ions to become efficient. Recently, w = 2w ci …
Preprint PublishedD. L. Keeling T. R. Barrett M. Cecconello C. D. Challis N. Hawkes O. M. Jones I. Klimek K. G. McClements A. Meakins J. Milnes M. Turnyanskiy The MAST team
The phenomenon of redistribution of neutral beam fast-ions due to MHD activity in plasma has been observed on many tokamaks and more recently has been a focus of research on MAST ( Turnyanskiy M. et al, 2013 Nucl. Fusion 53 053016 ). n=1 fishbone modes are observed to cause a large decrease in the neutron emission rate indicating to exist a signifi…
Preprint PublishedG. Xia Y. Liu Y. Liu G. Z. Hao L. Li
The synergetic effects of drift kinetic resonances, the resistive layer dissipation, the magnetic feedback, and the toroidal plasma flow on the stability of the resistive wall mode are numerically investigated using a full toroidal resistive magnetohydrodynamic-kinetic hybrid stability code MARS-K (Liu Y Q et al 2008 Phys. Plasmas 15 112503). It is…
Preprint PublishedZ.S. Qu M.J. Hole M. Fitzgerald
An unstable branch of energetic geodesic acoustic mode (EGAM) is found using the fluid theory with fast ions characterised by their narrow width in energy distribution and collective transit along field lines. This mode, with a frequency much lower than the thermal GAM frequency !GAM, is now confirmed as a new type of unstable EGAM : a reactive in…
Preprint PublishedJ. S. Wróbel D. Nguyen-Manh M. Y. Lavrentiev M. Muzyk S. L. Dudarev
The phase stability of fcc and bcc magnetic binary Fe-Cr, Fe-Ni, and Cr-Ni alloys, and ternary Fe-Cr-Ni alloys is investigated using a combination of density functional theory (DFT), cluster expansion (CE), and magnetic cluster expansion (MCE) approaches. Energies, magnetic moments, and volumes of more than 500 alloy structures have been evaluated …
Preprint Published