P. Helander
It was recently pointed out that the inductive electric field in a tokamak can give rise to toroidal and poloidal plasma rotation comparable to that sometimes observed in experiments. Here it is shown that the flow velocity of heavy impurity ions, which is normally what is measured, is lower than that of the bulk plasma for rotation produced in thi…
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…
PublishedC. N. Lashmore-Davies D. R. Mccarthy A. Thyagaraja
The linear and nonlinear dynamics of zonal flows and their interactions with drift wave turbulence is considered in the simple but illuminating generalized Charney–Hasegawa–Mima model due to Smolyakov et al. [Phys. Plasmas 7 , 1349 (2000)]. Two positive definite, exact, integral invariants associated with the full generalized Charney–Hasegawa…
PublishedChristian 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. Fülöp Peter J. Catto P. Helander
Neutral atoms can significantly influence the physics of tokamak edge plasmas, e.g., by affecting the radial electric field and plasma flow there, which may, in turn, be important for plasma confinement. Earlier work [Fulop et al. , Phys. Plasmas 5 , 3969 (1998)], assuming short mean-free path neutrals and Pfirsch–Schluter ions, has shown that th…
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 …
PublishedF. Andersson P. Helander L.-G. Eriksson
Relativistic electrons emit synchrotron radiation due to their gyro- and guiding-center motions in a curved magnetic field. In this article, the kinetic theory of relativistic electron beams is developed to account for radiation reaction by including the Abraham–Lorentz reaction force in the kinetic equation. As an application of this theory, the…
PublishedC. G. Gimblett R. J. Hastie
A model is developed to analyze the stabilization of the resistive wall mode (RWM) by plasma rotation. Central to the model is a cylindrical plasma that is ideal magnetohydrodynamic unstable in the absence of a wall, and possesses an internal resonance [J. M. Finn, Phys. Plasmas 2 , 198 (1995)]. This system is then a qualitative model for the actua…
PublishedP. Helander
The theory of neoclassical transport near the magnetic axis in a tokamak is discussed. It is shown that the ordinary treatment of transport in the plateau regime holds in most of the region within a trapped orbit width of the magnetic axis, and is not modified by ‘‘potato’’ orbits. It is also demonstrated that transport at low collisionalit…
PublishedR. J. La Haye R. J. Buttery S. Guenter G. T. A. Huysmans M. Maraschek et al.
The islands from tearing modes driven unstable and sustained by the helically perturbed neoclassical bootstrap current often provide the practical limit to long-pulse, high confinement tokamak operation. The destabilization of such ‘‘metastable’’ plasmas depends on a ‘‘seed’’ island exceeding a threshold. A database from similar reg…
Published