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Inoue, Takashi; Taniguchi, Masaki; Morishita, Takatoshi; Dairaku, Masayuki; Hanada, Masaya; Imai, Tsuyoshi*; Kashiwagi, Mieko; Sakamoto, Keishi; Seki, Takayoshi*; Watanabe, Kazuhiro
Nuclear Fusion, 45(8), p.790 - 795, 2005/08
The R&D of a 1 MeV accelerator and a large negative ion source have been carried out at JAERI. The paper presents following progress as a step toward ITER NB system. (1) Accelerator R&D: According to success in improvement of voltage holding capability, the acceleration test of H
ions up to 1 MeV class energy is in progress. H ion beams of 1 MeV, 100 mA class have been generated with a substantial beam current density (100 A/m
), and the current density is still increasing by the ion source tuning. (2) Large ion source R&D: One of major causes that limited the NB injection performance was spatial unifomity of negative ion production in existing negative-ion based NB systems. The present study revealed that the negative ions produced in the extraction region of the source were locally destructed by fast electrons leaking through magnetic filter. Some countermeasures and their test results are also described.
Inoue, Takashi; Taniguchi, Masaki; Morishita, Takatoshi; Dairaku, Masayuki; Hanada, Masaya; Imai, Tsuyoshi*; Kashiwagi, Mieko; Sakamoto, Keishi; Seki, Takayoshi*; Watanabe, Kazuhiro
Nuclear Fusion, 45(8), p.790 - 795, 2005/08
Times Cited Count：23 Percentile：58.16(Physics, Fluids & Plasmas)The R&D of a 1 MeV accelerator and a large negative ion source has been carried out at JAERI for the ITER NB system. The R&D is in progress at present toward: (1) 1 MeV acceleration of H ion beams at the ITER relevant current density of 200 A/m, and (2) improvement of uniform negative ion production over wide extraction area in large negative ion sources. Recently, H ion beams of 1 MeV, 140 mA level have been generated with a substantial beam current density (100 A/m). In the uniformity study, it has been clarified that electron temperature in the ion extraction region is locally high (
1 eV), which resulted in destruction of negative ions at a high reaction rate. Interception of fast electrons leaking through a transverse magnetic field called "magnetic filter" has been found effective to lower the local electron temperature, followed by an improvement of negative ion beam profile.
Inoue, Takashi
JAERI-Research 2005-006, 87 Pages, 2005/03
JAERI-Research-2005-006.pdf:10.53MB
Negative ion sources and accelerators have been developed toward the ITER neutral beam injector (NBI). According to an analysis of negative ion surface production, the "KAMABOKO" ion source has been developed maximizing its volume/surface ratio, for fast electron confinement followed by enhancement of atomic density. An "external filter" is equipped in the source, to suppress ion destruction by the fast electrons with efficient diffusion of the atoms to ion extraction region. H ions of 300 A/m was extracted at the pressure of 0.3 Pa. For the accelerator, vacuum insulation technology has been developed since insulation gas such as SF
is not applicable under radiation environment. Considering pressure in the accelerator (0.02
0.2 Pa), insulation guideline has been developed for both vacuum arc and glow discharges. Reduction of electric field stress at triple junction was effective to prevent flashover along insulator surface. H ion beams of 900 keV and 80 A/m (total ion current: 0.11 A) were obtained for several hundred shots.
ion beams in a proof-of-principle accelerator for ITERInoue, Takashi; Taniguchi, Masaki; Dairaku, Masayuki; Hanada, Masaya; Kashiwagi, Mieko; Morishita, Takatoshi; Watanabe, Kazuhiro; Imai, Tsuyoshi
Review of Scientific Instruments, 75(5), p.1819 - 1821, 2004/05
Times Cited Count：11 Percentile：50.59(Instruments & Instrumentation)The paper reports progress of proof-of-principle test of negative ion accelerator for ITER. The accelerator structure is immersed in vacuum, surrounded by a FRP insulator column as the vacuum boundary. So far, the beam energy has been limited due to poor voltage holding capability of the FRP insulator column. By lowering the electric field strength at the triple junction (interface of FRP insulator, metal flange and vacuum) with large stress ring installed inside the insulator column, high voltage of 1 MV was stably sustained for more than 2 hours. In the following beam test, acceleration of 900 keV, 100 mA H ion beam was succeeded. Although the current was lower (70 mA) at 1 MeV, the beam of this level has been stably accelerated for 6 days, 130 shots in total (each pulse length: 1 s).
ion beamlet by aperture displacementInoue, Takashi; Suzuki, Yasuo*; Miyamoto, Kenji; Okumura, Yoshikazu
JAERI-Tech 2000-051, 16 Pages, 2000/09
JAERI-Tech-2000-051.pdf:2.27MB
no abstracts in English
Inoue, Takashi; Miyamoto, Kenji; Nagase, Akihito*; Okumura, Yoshikazu; Watanabe, Kazuhiro
JAERI-Tech 2000-023, p.27 - 0, 2000/03
JAERI-Tech-2000-023.pdf:1.18MB
no abstracts in English
beam accelerator for neutral beam injectorWatanabe, Kazuhiro; Fujiwara, Yukio; Hanada, Masaya; Inoue, Takashi; Miyamoto, Kenji; Miyamoto, Naoki*; Okumura, Yoshikazu; Sato, Kazuyoshi
Fusion Technology 1998, 1, p.493 - 496, 1998/00
no abstracts in English
Watanabe, Kazuhiro; ; Aoyagi, Tetsuo; ; Fujiwara, Yukio; Honda, Atsushi; Inoue, Takashi; Ito, Takao; Kawai, Mikito; Kazawa, Minoru; et al.
Radiation Physics and Chemistry, 49(6), p.631 - 639, 1997/00
Times Cited Count：3 Percentile：30.01(Chemistry, Physical)no abstracts in English
Watanabe, Kazuhiro; ; Fujiwara, Yukio; Honda, Atsushi; Inoue, Takashi; Kazawa, Minoru; Kuriyama, Masaaki; Miyamoto, Kenji; Miyamoto, Naoki*; Mogaki, Kazuhiko; et al.
16th IEEE/NPSS Symp. on Fusion Engineering (SOFE '95), 1, p.642 - 645, 1996/00
no abstracts in English
Inoue, Takashi; Hanada, Masaya; ; Miyamoto, Kenji; Ohara, Yoshihiro; Okumura, Yoshikazu; Watanabe, Kazuhiro
JAERI-Tech 94-007, 89 Pages, 1994/08
no abstracts in English
Inoue, Takashi; Miyamoto, Kenji; Mizuno, Makoto; Okumura, Yoshikazu; Ohara, Yoshihiro; G.D.Ackerman*; C.F.Chan*; W.S.Cooper*; J.W.Kwan*; M.C.Vella*
15th IEEE/NPSS Symp. on Fusion Engineering,Vol. 1, 0, p.474 - 477, 1994/00
no abstracts in English
Inoue, Takashi; Hanada, Masaya; ; Mizuno, Makoto; Ohara, Yoshihiro; Okumura, Yoshikazu; Suzuki, Yasuo*; Tanaka, Masanobu*; Watanabe, Kazuhiro
Plasma Devices and Operations, 3, p.211 - 222, 1994/00
no abstracts in English
beam in an electrostatic acceleratorWatanabe, Kazuhiro; Hanada, Masaya; Inoue, Takashi; ; Miyamoto, Kenji*; Mizuno, Makoto; Ohara, Yoshihiro; Okumura, Yoshikazu
EP-93-48, p.11 - 19, 1993/08
no abstracts in English
Watanabe, Kazuhiro; Hanada, Masaya; Inoue, Takashi; ; Mizuno, Makoto; Ohara, Yoshihiro; Okumura, Yoshikazu; Suzuki, Yasuo*; Tanaka, Hideki*; Tanaka, Masanobu*
Proc. of 14th Int. Conf. on Plasma Physics and Controlled Nuclear Fusion Research, p.371 - 378, 1993/00
no abstracts in English
ion sourceInoue, Takashi; ; Ohara, Yoshihiro; Okumura, Yoshikazu; M.Bacal*; P.Berlemont*
Plasma Sources Sci. Technol., 1, p.75 - 81, 1992/00
Times Cited Count：16 Percentile：54.77(Physics, Fluids & Plasmas)no abstracts in English
ion beamsWatanabe, Kazuhiro; Hanada, Masaya; Inoue, Takashi; Mizuno, Makoto; Ohara, Yoshihiro; Okumura, Yoshikazu; Suzuki, Yasuo*; Tanaka, Hideki*; Tanaka, Masanobu*
Dai-2-Kai Ryushisen No Sentanteki Oyo Gijutsu Ni Kansuru Wakushoppu, p.107 - 110, 1991/00
no abstracts in English
Watanabe, Kazuhiro; Hanada, Masaya; Inoue, Takashi; Mizuno, Makoto; Ohara, Yoshihiro; Okumura, Yoshikazu; Suzuki, Yasuo*; Tanaka, Hideki*; Tanaka, Masanobu*
Dai-4-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.85 - 88, 1991/00
no abstracts in English
