-
Author(s):
S. Satake, M. Okamoto and H. Sugama
-
Title:
Lagrangian Neoclassical Transport Theory Applied to the Region near the Magnetic Axis
Date of publication:
June 2002
-
Key words:
neoclassical transport, potato orbit, finite-width effect
-
Abstract:
Neoclassical transport theory around the magnetic axis of a tokamak is studied, in which relatively wide "potato" orbits play an important role in transport. Lagrangian for mulation of transport theory, which has been investigated to reflect finiteness of guiding-center orbit widths to transport equations, is developed in order to analyze neoclassical transport near the axis for a low-collisionality plasma. The treatment of self-collision term in Lagrangian formulation is revised to retain momentum conservation property of it. With directly reflecting the orbital properties of all the types of orbits in calculation, the ion thermal conductivity around the axis is found to decrease than from that predicted by conventional neoclassical theory. This result supports recent numerical simulations which show the reduction of thermal conductivity near the magnetic axis.
-
|
