Present status of LHD construction and experimental program

A major goal of the Large Helical Device (LHD) Project is to demonstrate a high potential for the Heliotron-type device to produce current-less-steady-state plasmas with a large Lawson parameter but without any hazardous plasma current disruption. The LHD is a superconducting toroidal device with a continuous helical divertor as a powerful edge control tool. Its major radius, and maximum magnetic field strength are 3.9 m and 4 Tesla, respectively. It has l/m=2/10, SC helical coils and three sets of SC poloidal coils, of which coil currents and the stored energy are 7.8, 5.0, −4.5, −4.5, and 1.6 GJ, respectively. SC is the major technological issue of the LHD project. The LHD has now successfully completed the seventh year of an eight year construction schedule. Engineering research and development necessary for the LHD construction have almost reached completion, and we have now accomplished more than 80% of a tough and long construction schedule. The detailed planning of the practical experiments is progressing to accelerate the buildup of the initial experiments in conjunction with many collaborators at universities and other institutions.