title: Twenty barrel in situ pipe gun type solid hydrogen pellet injector for the Large Helical Device.
abstract: A 20 barrel solid hydrogen pellet injector, which is able to inject 20 cylindrical pellets with a diameter and length of between 3.0 and 3.8 mm at the velocity of 1200 m/s, has been developed for the purpose of direct core fueling in LHD (Large Helical Device). The in situ pipe gun concept with the use of compact cryo-coolers enables stable operation as a fundamental facility in plasma experiments. The combination of the two types of pellet injection timing control modes, i.e., pre-programing mode and real-time control mode, allows the build-up and sustainment of high density plasma around the density limit. The pellet injector has demonstrated stable operation characteristics during the past three years of LHD experiments.
authors.affiliation: National Institute for Fusion Science, Toki, Gifu 509-5292, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Sakamoto
authors.forename: Gen
authors.initials: G
authors.lastname: Motojima
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hayashi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Inoue
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ito
authors.forename: Hideki
authors.initials: H
authors.lastname: Ogawa
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Takami
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yokota
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada