A. De Backer D.R. Mason C. Domain D. Nguyen-Manh M.-C. Marinica L. Ventelon C.S. Becquart S.L. Dudarev
In a fusion tokamak, the plasma of hydrogen isotopes is in contact with tungsten at the surface of a divertor. In the bulk of the material, the hydrogen concentration profile tends towards dynamic equilibrium between the flux of incident ions and their trapping and release from defects, either native or produced by ion and neutron irradiation. The …
Preprint PublishedColin Windsor Geoff Cottrell Richard Kemp
Recent papers have demonstrated that the yield stress and the Charpy ductile to brittle transition temperature shift at the high irradiation levels of a fusion power plant may be predicted from measurements at lower irradiation levels using neural networks. It was demonstrated that the extrapolation inherent in such predictions could be validated p…
PublishedG A Cottrell R Kemp
In a rotating plasma, with co-neutral beam injection (NBI), the Doppler shift of the NBI particles, as viewed in the frame of the plasma, can result in a significant reduction in the beam-driven (Ohkawa) current when the rotation is strong. The correction applies to the toroidal fast-ion current calculated for a non-rotating plasma and is independe…
PublishedColin Windsor Geoff Cottrell Richard Kemp
Recent predictions have been made of metallurgical properties of low-activation ferritic/martensitic steels alloys at the high irradiation levels (displacements per atom or dpa) needed for a fusion power plant as based on measurements at low irradiation levels where more data is available. These have been published for the yield stress and for the …
PublishedColin Windsor Geoff Cottrell Richard Kemp
A prediction has been made of the Charpy ductile-brittle transition temperature at high irradiation levels from a dataset of 459 low-activation ferritic/martensitic steels. It follows a similar study of the yield stress of some 1811 similar alloys (Windsor et al , Modelling Simul. Mater. Sci. Eng. 16 (2008) 025005) Neural networks have previously b…
PublishedG. A. Cottrell R. Pampin N. P. Taylor
We present calculations of the transmutation of initially pure tungsten first-wall and divertor plasma-facing armor intoW-Re-Os alloys in the European Union Power Plant Conceptual Study (PPCS) fusion plant models A, B, and AB. The fusion neutron spectrum was modeled using the MCNP Monte Carlo code including resonance self-shielding effects, and we …
PublishedK. G. McClements C. Hunt R. O. Dendy G. A. Cottrell
Ion cyclotron emission (ICE) excited by collective instability of fusion a particles has been observed during deuterium-tritium experiments with radio-frequency heating and neutral beam injection (NBI) in the Joint European Torus. A model based on classical a-particle confinement is broadly consistent with this data. ICE spectra from discharges wit…
PublishedK. G. McClements R. O. Dendy C. N. Lashmoredavies G. A. Cottrell S. Cauffman et al.
Ion cyclotron emission ~ ICE ! has been observed during neutral beam-heated supershots in the Tokamak Fusion Test Reactor ~ TFTR ! @ Phys. Rev. Lett. 72 , 3526 ~ 1994 !# deuterium–tritium campaign at fusion product cyclotron harmonics. The emission originates from the outer midplane edge plasma, where fusion products initially have an anisotropic…
PublishedR. O. Dendy C. N. Lashmoredavies K. F. Kam
Intense superthermal ion cyclotron emission (ICE) has been observed from tokamak plasmas. The power spectrum displays narrow peaks at multiple harmonics of the background ion cyclotron frequency [Cottrell and Dendy, Phys. Rev. Lett. 60, 33 (1988)] in Ohmic deuterium plasmas, and the radiation appears to be driven by the fusion ion population in the…
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