'Japan Society of Plasma Science and Nuclear Fusion Research'
Doi
Abstract
The effect of the pitch modulation of the helical coils on the core plasma performance of the LHD-type helical fusion reactor has been examined. The analysis of the MHD stability and neoclassical transport for the pitch modulation α = 0.0 and 0.1 has been conducted based on the finite-beta equilibrium calculated by the HINT code. It was found that the MHD stability is clearly improved without deteriorating the energy transport property by changing the pitch modulation α from 0.1 to 0.0. The reachable operation region expands to the higher density and the expected fusion gain can increase from ∼10 to ∼20. Because the change of the pitch modulation α from 0.1 to 0.0 requires only a slight change in the shape of the helical coils, the engineering design including the maintenance method that has been examined for the reactor with α = 0.1 can be applied without a major modification