Manufacturing development of the NCSX modular coil winding forms and vacuum vessel

The National Compact Stellarator Experiment (NCSX) is the first of a new class of stellarators known as "compact stellarators". Stellarators are characterized by three dimensional magnetic fields and plasma shapes and are the best-developed class of magnetic fusion devices after the tokamak. Stellarators are attractive because they solve critical problems of magnetic fusion energy: steady state operation without current drive and stable operation without feedback control or rotation drive. The differentiating feature of the compact stellarator is the use of a small plasma current in conjunction with external magnetic fields to provide the required plasma shaping and confinement. This permits a more compact stellarator design. Many of the components of NCSX are conventional in design and manufacture; however, two of the most critical components, the vacuum vessel and the modular coil winding forms, are also the most challenging components to manufacture. This paper describes design of these two critical elements of NCSX and the three-phase program that is being used in the manufacturing development of these components.