Speaker
Vyacheslav Savin
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1041.pdf
Fast ion effects on the magnetic islands in a tokamak
V. Y. Savin1, 2, S. V. Konovalov1
1
National Research Center «Kurchatov institute», Moscow, Russian Federation
2
National Research Nuclear University MEPhI (Moscow Engineering Physics Institute),
Moscow, Russian Federation
It is known that the presence of helical perturbations that violate the axial symmetry
of the magnetic field of a tokamak leads to the formation of magnetic islands with a width
∆𝑚 ~√𝐵̃, as well as to a change in the drift trajectories of charged particles, coupled with
their radial redistribution and/or additional losses. In this case, according to [1], the drift
trajectories of fast ions, characterized by a significant deviation from the magnetic surfaces,
λ, are more stable to helical perturbations of the magnetic field than magnetic surfaces. In
turn, the perturbation of the drift motion of fast ions leads to the appearance of a helical
current perturbation capable of both facilitating and preventing the growth of the magnetic
island. In the present paper, we consider both the case λ>Δm [2], when the helical current
perturbation is due to the compensating electron drift, 𝑉𝐸 ~[𝐸̃ × 𝑩], and the inverse, λ
