@techreport{oai:nifs-repository.repo.nii.ac.jp:00009975,
 author = {Motojima,  O. and Akaishi,  K. and Chikaraishi,  H. and Funaba,  H. and Hamaguchi,  S. and Imagawa,  S. and Inagaki,  S. and Inoue,  N. and Iwamoto,  A. and Kitagawa,  S. and Komori,  A. and Kubota,  Y. and Maekawa,  R. and Masuzaki,  S. and Mito,  T. and Miyazawa,  J. and Morisaki,  T. and Muroga,  T. and Nagasaka,  T. and Nakmura,  Y. and Nishimura,  A. and Nishimura,  K. and Noda,  N. and Ohyabu,  N. and Sagara,  S. and Sakakibara,  S. and Sakamoto,  R. and Satoh,  S. and Satow,  T. and Shoji,  M. and Suzuki,  H. and Takahata,  K. and Tamura,  H. and Watanabe,  K. and Yamada,  H. and Yamada,  S. and Yamaguchi,  S. and Yamazaki,  K. and Yanagi,  N. and Baba,  T. and Hayashi,  H. and Iima,  M. and Inoue,  T. and Kato,  S. and Kato,  T. and Kondo,  T. and Moriuchi,  S. and Ogawa,  H. and Ohtake,  I. and Ooba,  K. and Sekiguchi,  H. and Suzuki,  N. and Takami,  S. and Taniguchi,  Y. and Tsuzuki,  T. and Yamamoto,  N. and Yasui,  K. and Yonezu,  H. and Fujiwara,  M. and Iiyoshi,  A.},
 month = {Oct},
 note = {In March 1998, the large helical device (LHD) project finally completed its 8 years construction schedule. LHD is a superconducting (SC) heliotron type device with R=3.9 m, a_p=0.6 m, and B=3 T, which has simplex and continuous large helical coils. The major mission of LHD is to demonstrate the high potential of currentless helical-toroidal plasmas, which are free from current disruption and have an intrinsic potential for steady state operation. After the intensive physics design studies in the 1980's, the necessary programs of SC engineering R&D were made and carried out, and as a result, LHD fabrication technologies were successfully developed. In this process, a significant database on fusion engineering has been established. These achievements have been made in various areas, such as the technologies of SC conductor development. SC coil fabrication, liquid helium (LHe) and supercritical helium (SHe) cryogenics, development of low temperature structural materials and welding, operation and control, and power supply systems and related SC coil protection schemes. They are integrated, and nowadays comprise a major part of the LHD relevant fusion technology area. These Issues correspond to a necessary technological duta base for the next step of future reactor designs. In addition, we could increase this with successful commissioning tests just after the completion of LHD machine assembly phase, which consisted of vacuum leak test, LHe cooldown test, and coil current excitation test. We recapitulate and highlight these LHD relevant engineering developments in this paper. To summarize our construction of LHD as an SC device, the critical design with NbTi SC material has been successfully accomplished by our R&D activities, which enables us to move into a new regime of fusion experiments.},
 title = {Progress Summary of LHD Engineering Design and Construction},
 year = {1998}
}