@techreport{oai:nifs-repository.repo.nii.ac.jp:00009836,
 author = {Kaneko,  O. and Takeiri,  Y. and Tsumori,  K. and Oka,  Y. and Osakabe,  M. and Akiyama,  R. and Kawamoto,  T. and Asano,  E. and Kuroda,  T.},
 month = {Sep},
 note = {A high power neutral injection heating system, which is based on the negative ion beam technology, is under construction for the Large Helical Device (LHD). The injection power of 15MW is expected for 10 seconds with 180keV hydrogen. Such high energy is required to inject the beam tangentially in the LHD that the use of negative ions is inevitable. The system consists of two beam lines with four negative ion sources. A large amount of negative ion beam (160A) is required with the high current density (> 35mA/cm^2). The design of ion source is carried out on the basis of our R & D in these seven years, where we have succeeded in the high efficient negative ion production and the high quality beam formation.  The other components of beam line and the power supplies are designed on the basis of conventional neutral beam technology. Although the NBI system is designed in pulse operation, its duty cycle is rather high (10 seconds in every 5 minutes) because the magnetic field of LHD is generated in steady state. This is a tough condition for the heat removal systems such as the beam dumps.},
 title = {Development of Negative-Ion-Based Neutral Beam Injector for the Large Helical Device},
 year = {1996}
}