Photo‐neutralization of Negative Ion Beam for Future Fusion Reactor

An exploratory study of negative ion beam photo‐neutralization for future fusion reactors is explained. A refolded Fabry‐Perot cavity system is proposed, with which a 60% neutralisation efficiency could be reached with low electric power consumption. The system would make use of sophisticated optical‐cavity locking systems, which have been developed recently for gravitational‐wave optical detection. The ITER Neutral beam Injector is taken as an example.