Chaotic diffusion across a magnetic island due to a single electrostatic drift wave
It is shown that the guiding centre motion around a single chain of magnetic islands in a tokamak can become chaotic in the presence of a single electrostatic drift wave. This process leads to radial diffusion across the islands without magnetic braiding. The chaotic diffusion appears to be selective in velocity space. Using realistic values of the physical parameters, it is deduced that this process can be effective in normal conditions; with the observed islands and electrostatic field values corresponding to measured density fluctuations, this diffusion concerns ions with velocities higher than thermal and almost all of the electron population. The consequences for radial diffusion are discussed.
Bibliographic Reference: Report: EUR-CEA-FC 1397 EN (1990) 57 pp.
Availability: Available from CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Record Number: 199011293 / Last updated on: 1994-12-01
Original language: en
Available languages: en