A new helical-axis heliotron device, Heliotron J, is now being constructedat the Institute of Advanced Energy of Kyoto University with the goal ofdemonstrating its improved helical confinement property in the helical-axisheliotron line. The design feature of Heliotron J is, as compared with that ofHeliotron E, the reduced neoclassical transport (near the tokamak levelaccording to the DKES code) and the enhanced average beta limit (4% for theMercier criterion) with small bootstrap current, which carries the potentialfor developing the currentless `quasi-isodynamic' optimization. The deviceparameters are as follows: the major plasma radius of 1.2 m, the averageplasma minor radius of 0.1-0.2 m, the magnetic field strength on the magneticaxis of 1.5 T, the vacuum rotational transform of 0.2-0.8 with a low magneticshear, and the magnetic well depth of 1.5% at the plasma edge, with heatingsystems such as ECH(0.5 MW), NBI(1.5 MW), and ICRF(2.5 MW). The feasibility ofthe helical-axis heliotron concept and its ability to explore high-qualityconfinement surfaces with a divertor will be fully tested in Heliotron J. Thefirst plasma was planned to be produced in the autumn of 1999.