Review of stellarator/heliotron design issues towards MFE DEMO

The first review is presented for the recent stellarator designs of FFHR, HSR, ARIES-CS, which are based on the experimental device projects of LHD, W-7X, NCSX, respectively. The main advantageous features of those designs are common on (1) current-free plasmas, which leads to steady, high Q and disruption-free reactors and (2) high density operations, which largely reduces the diverter heat load. Design optimization and engineering feasibility are highlighted including maintainability, fabricability and showing future R&D key issues with prospect towards DEMO.