Study of magnetic field lines after perturbation of a toroidal field with magnetic surfaces
This article studies the magnetic field lines of the field B = B(0) + m B(1) where B(0) is a toroidal magnetic field with magnetic surfaces centred around a common axis, B(1) is a perturbatory magnetic field and m is small. It is shown that in general this perturbation creates magnetic islands around the surfaces where m = 0 under a rational rotation transformation. For the general field B(1) is calculated from the value of q on the axis of the islands created, giving the size of the islands measured by the value of the magnetic flux across the island to the separatrix. The method can be generalised to calculations for less important islands on the other magnetic surfaces under rational rotation transformations. Having obtained the expressions for q, Chirikov's criterion can be applied in order to define the limit of turbulence when two neighbouring islands come into contact.
Bibliographic Reference: Report: EUR-CEA-FC-1349 FR (1988)
Availability: Available from CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Record Number: 198910334 / Last updated on: 1994-12-01
Original language: fr
Available languages: fr