Christian Girard Jean-Philippe Gaillard Gabriel Marbach Gilio Cambi Ian Cook Lise-Lotte Johansson Rainer Meyder Julian Mustoe Tonio Pinna
The Safety and Environmental Assessment of Fusion Power (SEAFP) was performed in the framework of the European fusion program, whose results have already been published. The European Commission decided to continue this program for some identified issues that required development. One of these issues was the analysis and specification of the contain…
PublishedT. Johnson T. Hellsten M. Mantsinen V. Kiptily S. Sharapov et al.
The RF-induced pinch of 3 He minority ions has been observed in JET affecting the diamagnetic energy, the fast ion energy content, the sawtooth period, the Alfvén eigenmode excitation and the y-emission. Further, the y-emission is consistent with RF-detrapping into co-current passing orbits. The results from the SELFO code are consistent with the …
PublishedN. J. Peacock R. Barnsley M. G. O’Mullane M. R. Tarbutt D. Crosby et al.
The equilibrium state in tokamak core plasmas has been studied using the relative intensities of resonance x-ray lines. A full spatial analysis involves comparison of the line intensities with ion diffusion calculations, including relevant atomic rates. A zero-dimensional model using a global ion loss rate approximation has also been demonstrated b…
PublishedBrian Lloyd
Neoclassical tearing modes (NTMs) may limit performance in Next Step tokamaks, degrading confinement and possibly leading to disruption. In recent years, excellent experimental and theoretical progress has been made in understanding NTMs and their control. The properties of NTMs and various stabilization schemes are described. Recent experimental r…
PublishedC. N. Lashmore-Davies
A cylindrical model with an equilibrium surface current and a uniform equilibrium plasma flow velocity parallel to the axis of the cylinder is used to investigate resistive wall instability. This system can be unstable to the ideal, external kink mode, which can be stabilized by the presence of a perfectly conducting wall. This is the classic condi…
PublishedS. C. Chapman R.O. Dendy B. Hnat
Confinement phenomenology characteristic of magnetically confined plasmas emerges naturally from a simple sandpile algorithm when the parameter controlling redistribution scale length is varied. Close analogs are found for enhanced confinement, edge pedestals, and edge localized modes (ELMs), and for the qualitative correlations between them. These…
PublishedT. Edlington R. Martin T. Pinfold
The mega-ampere spherical tokamak (MAST) experiment is a new, large, low aspect ratio device operating its first experimental physics campaign. Designed to study a wide variety of plasma shapes with up to 2 MA of plasma current with an aspect ratio down to 1.3, the poloidal field (PF) coils used for plasma formation, equilibrium and shaping are ins…
PublishedR. A. Cairns C. N. Lashmore-Davies
An approximation to the relativistic broadening of an electron cyclotron resonance is obtained by including only the effect of the momentum parallel to the magnetic field. This approximation is then applied to the calculation of the absorption of the electromagnetic X-mode and compared to the full relativistic analysis with which it agrees very wel…
PublishedS. C. Chapman R. O. Dendy B. Hnat
An avalanche or ‘‘sandpile’’ model is discussed that generalizes the original self-organized criticality avalanche model of Bak, Tang, and Wiesenfeld [Phys. Rev. Lett. 59 , 381 (1987)] to include spatially extended local redistribution. A single control parameter specifies the spatial extent of local redistribution when the critical gradien…
PublishedN. C. Hawkes B. C. Stratton T. Tala C. D. Challis G. Conway R. Deangelis C. Giroud J. Hobirk E. Joffrin P. Lomas P. Lotte J. Mailloux D. Mazon E. Rachlew S. Reyes-Cortes E. Solano K-D. Zastrow
Simultaneous current ramping and application of lower hybrid heating and current drive (LHCD) have produced a region with zero current density within measurement errors in the core of JET tokamak optimized shear discharges. The reduction of core current density is consistent with a simple physical explanation and numerical simulations of radial cur…
Published