Concept of plasma heating and current drive neutral beam system for fusion neutron source "DEMO-FNS"
- Dr. Sergey ANANYEV
- Dr. Sergey ANANYEV (NRC "Kurchatov Institute")
Steady-state operation of a fusion neutron source (FNS) requires plasma heating and current drive by means of additional power delivered by neutral beams. Six neutral beam injectors (NBI) will provide DEMO-FNS machine with additional heating power up to 30 MW, with neutral particle energy 500 keV. NBI systems developed for ITER can serve as the prototype for DEMO-FNS, as both systems have similar ion source current, with accelerated beam power in ITER NBI (1MeV) being twice as large as in DEMO-FNS. The paper describes the NBI system with account of its integration to DEMO-FNS tokamak complex. Significant differences in the design elements of injectors for DEMO-FNS are associated with smaller values of critical parameters such as injected power, the values of peak power densities on the walls along the beam path, smaller gas flows in the injector compared to the injectors being developed for ITER. At this stage, we deliberately do not consider systems that are auxiliary to the injection complex of fast atoms, but we emphasize the complexity of their design and integration into tokamak systems. We proposed the ITER NBI parameters revision to optimize the design of the injector and its components for the DEMO-FNS facility. Optimal beam transmission line configuration has been chosen and the loads on its elements have been calculated.