Abstract
Large size hydrogen neutral beam injectors (NBI) used a negative ion source (NNBI) as well as a proton source (PNBI) were developed for the large helical device (LHD). The injected power from NNBI and PNBI have reached 16 MW and 6.8 MW, respectively. These injected powers have outstripped the nominal beam powers. A diagnostic system of beam-emitted hydrogen visible spectrum has been installed along the beam injection axis to estimate the energy fraction on PNBI. The full energy beam component is about half which is equivalent to 70% of injected beam power. The attenuation of high energy neutral beam is also observed on NNBI. The peak density distribution is effective to increase beam deposition power.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
