PPPL-3393 is available in pdf or postscript formats.

Timescales for Non-inductive Current Buildup In Low-aspect-ratio Toroidal Geometry

Author: S.C. Jardin

Date of PPPL Report: November 1999

Published in: Nucl. Fusion 40 (June 2000) 1101-1112.

The fundamental differences between inductive and non-inductive current buildup are clarified and the associated time-scales and other implications are discussed. A simulation is presented whereby the plasma current in a low-aspect-ratio torus is increased primarily by the self-generated bootstrap current with only 10% coming from external current drive. The maximum obtainable plasma current by this process is shown to scale with the toroidal field strength. The basic physics setting the time-scales can be obtained from a 1D analysis. Comparisons are made between the timescales found here and those reported in the experimental literature.