MODULE STELLARATOR SYSTEM MADE OF L=+ -2 HELICES WITH DIFFERENT PITCHANGLES/

A new design method for the modularization of helical coils of a stell arator type has been proposed. This is an extension of the interchange able module stellarator (IMS) method, and L = +/-2 helices with differ ent pitch angles are utilized. This modular coil system exerts less er ror field effects on magnetic properties, so it may have large magneti c surfaces. The magnetic axis exists nearly at the coil center without any additional fields. It may have larger transform than that designe d from the original IMS method.