The Conducting Shell Stellarator: A Simple Means for Producing Complicated Fields
Author: G.V. Sheffield
One of the main characteristics of stellarators, both helical 1 and modular 2, is that their coil sets must take difficult shapes in order to produce the complicated stellarator magnetic fields. The complex coil shapes make fabrication difficult and costly compared to say the toroidal field (TF) coil set of a tokamak. The conducting shell stellarator (CSS) configuration described in this report shows that complicated stellarator fields can be produced by inducing eddy currents in a conducting shell from a simple TF coil set (a field that varies like 1/R). This technique is applicable not only to a pulsed system at room or cryogenic temperatures, but can be implemented for a superconducting TF with a superconducting shell in a stellarator reactor. The CSS has the added benefit that within this device the metalic shell which can be made up of discrete plates can be changed out and replaced with new plates to create a different stellarator configuration within the same TF coil set. The work of creating the complicated magnetics is done by the passive conductor reshaping the simple TF field.
Note:Please contact the author, George V. Sheffield, Princeton Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543, or send e-mail to caphilli@pppl.gov for figures.