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Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Grisham, L. R.*; Hatayama, Akiyoshi*; Shibata, Takanori*; Yamamoto, Takashi*; Akino, Noboru; Endo, Yasuei; et al.
Fusion Engineering and Design, 96-97, p.616 - 619, 2015/10
Times Cited Count：11 Percentile：67.3(Nuclear Science & Technology)In JT-60 Super Advanced for the fusion experiment, 22A, 100s negative ions are designed to be extracted from the world largest ion extraction area of 450 mm 
1100 mm. One of the key issues for producing such as high current beams is to improve non-uniform production of the negative ions. In order to improve the uniformity of the negative ions, a tent-shaped magnetic filter has newly been developed and tested for JT-60SA negative ion source. The original tent-shaped filter significantly improved the logitudunal uniformity of the extracted H
ion beams. The logitudinal uniform areas within a 
10 deviation of the beam intensity were improved from 45% to 70% of the ion extraction area. However, this improvement degrades a horizontal uniformity. For this, the uniform areas was no more than 55% of the total ion extraction area. In order to improve the horizontal uniformity, the filter strength has been reduced from 660 Gasus
cm to 400 Gasuscm. This reduction improved the horizontal uniform area from 75% to 90% without degrading the logitudinal uniformity. This resulted in the improvement of the uniform area from 45% of the total ion extraction areas. This improvement of the uniform area leads to the production of a 22A H ion beam from 450 mm 1100 mm with a small amount increase of electron current of 10%. The obtained beam current fulfills the requirement for JT-60SA.
Yamanaka, Haruhiko; Maejima, Tetsuya; Terunuma, Yuto; Watanabe, Kazuhiro; Kashiwagi, Mieko; Hanada, Masaya
JAEA-Technology 2014-037, 12 Pages, 2014/12
JAEA-Technology-2014-037.pdf:4.27MB
Resistivity of a high temperature pure water has been measured up to 180
C which is the maximum water temperature in the ITER Neutral Beam Injector. The resistivity of the pure water is decreased by increasing the water temperature. It was found that even different resistivity water of 9 M
cm and 5 Mcm showed almost the same resistivity at the higher temperature region of 100C. The resistivity of 0.36 Mcm was measured at the temperature of 180C. This resistivity agreed well to the calculated value for the theoretical pure water.
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Grisham, L. R.*; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; et al.
Review of Scientific Instruments, 85(2), p.02B314_1 - 02B314_4, 2014/02
Times Cited Count：14 Percentile：50.88(Instruments & Instrumentation)Non-uniformity of the negative ion beams in the JT-60 negative ion source was improved by modifying an external magnetic field to a tent-shaped magnetic field for reduction of the local heat loads in the source. Distributions of the source plasmas (H
ions and H
atoms) of the parents of H ions converted on the cesium covered plasma grids were measured by Langmuir probes and emission spectroscopy. Beam intensities of the H ions extracted from the plasma grids were measured by IR camera from the back of the beam target plate. The tent-shaped magnetic field prevented the source plasmas to be localized by B grad B drift of the primary electrons emitted from the filaments in the arc chamber. As a result, standard derivation of the H ions beams was reduced from 14% (the external magnetic field) to 10% (the tent-shaped magnetic field) without reduction of an activity of the H ion production.
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Inoue, Takashi; Kashiwagi, Mieko; Grisham, L. R.*; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; et al.
Plasma and Fusion Research (Internet), 8(Sp.1), p.2405146_1 - 2405146_4, 2013/11
Distributions of H and H in the source plasmas produced at the end-plugs of JT-60 negative ions source were measured by Langmuir probes and emission spectroscopy in order to experimentally investigate the cause of lower density of the negative ions extracted from end-plugs in the source. Densities of H and H in end-plugs of the plasma grid in the source were compared with those in the center regions. As a result, lower density of the negative ion at the edge was caused by lower beam optics due to lower and higher density of the H and H.
Sasaki, Shunichi; Endo, Yasuei; Terunuma, Yuto; Hanada, Masaya; Kojima, Atsushi
no journal, ,
no abstracts in English
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; Ozeki, Masahiro; et al.
no journal, ,
Non-uniformity of the negative ion beams in the JT-60 negative ion source with the world-largest ion extraction area was improved by modifying the magnetic filter in the source from the PG filter to a tent-shaped filter. The magnetic design via electron trajectory calculation showed that the tent-shaped filter was expected to suppress the localization of the primary electrons emitted from the filaments and created uniform plasma with positive ions and atoms of the parent particles for the negative ions. By modifying the magnetic filter to the tent-shaped filter, the uniformity defined as the deviation from the averaged beam intensity was reduced from 14% of the PG filter to 
10% without a reduction of the negative ion production.
Tobari, Hiroyuki; Hanada, Masaya; Watanabe, Kazuhiro; Kashiwagi, Mieko; Dairaku, Masayuki; Yamanaka, Haruhiko; Maejima, Tetsuya; Umeda, Naotaka; Abe, Hiroyuki; Terunuma, Yuto; et al.
no journal, ,
JAEA has started procurement activities for ITER NB test facility (NBTF). NBTF being under construction in Padova, Italy has an objective to establish beam technology for 1 MeV, 40 A D- beam prior to ITER operation. JAEA procures high voltage components of 1 MV power supply such as insulating transformer and HV bushing as insulating feedthrough. Requirements to realize those components exceeds existing technology level, hence JAEA has pushed R&D. As for 1 MV insulating transformer, insulating method with double-walled insulator was newly developed. As for the HV bushing, a new forming method of the world largest ceramic ring and brazing technique were developed, and then a technology that meets ITER requirement has been confirmed. Procurement activities have been started from 2012 and now is undergoing as scheduled. Manufacturing of components will be completed by 2015 and those will be transported and installed in Padova in 2016. Commissioning will start in 2017.
Yamanaka, Haruhiko; Watanabe, Kazuhiro; Kashiwagi, Mieko; Tobari, Hiroyuki; Maejima, Tetsuya; Hanada, Masaya; Terunuma, Yuto
no journal, ,
A high-energy and high power neutral beam injectors (NBI) of 1 MeV, 16.5 MW neutral power/injector are required for plasma heating and current drive in ITER. A Neutral Beam Test Facility (NBTF), which has the same capacity as the ITER NBI, is constructed at the RFX site in Padua of Italy to demonstrate the specifications and to establish its operation techniques. Capacity of the power supply is DC -1 MV and 60 MW for the beam source with pulse duration up to 3600 s. JAEA as Japan Domestic Agency (JADA) provides ultra-high voltage components of a DC -1 MV power supply for NBTF. To fabricate such UHV NBI power supply components, detailed design has been conducted.
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; Ozeki, Masahiro; et al.
no journal, ,
no abstracts in English
Maejima, Tetsuya; Watanabe, Kazuhiro; Kashiwagi, Mieko; Yamanaka, Haruhiko; Terunuma, Yuto; Umeda, Naotaka; Dairaku, Masayuki; Tobari, Hiroyuki; Yamashita, Yasuo*; Shibata, Naoki; et al.
no journal, ,
no abstracts in English
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; Ozeki, Masahiro; et al.
no journal, ,
In JT-60SA for the fusion experiment, 22A, 100s D ions are designed to be extracted from the world largest ion extraction area of 450 mm 1100 mm. One of the key issues for producing such as high current beams is to improve non-uniform production of the negative ions. In order to improve the uniformity of the negative ions, a tent-shaped magnetic filter has newly been developed and tested for JT-60SA negative ion source. The non-uniformity of the negative ions is experimentally found to be caused by a localization of H ions and H atoms, which are produced by primary electrons emitted from filaments and are converted to H ions on the surface of plasma grids covered with cesium. By modifying from the conventional magnetic filter to the tent-shaped one, the uniform areas were expanded from 45% of the full extraction areas in the conventional magnetic filter to 60%. Finally, 22A production of the negative ion beams was successfully achieved in the uniform areas.
Yamanaka, Haruhiko; Watanabe, Kazuhiro; Kashiwagi, Mieko; Maejima, Tetsuya; Terunuma, Yuto; Umeda, Naotaka; Dairaku, Masayuki; Tobari, Hiroyuki; Hanada, Masaya
no journal, ,
no abstracts in English
Tobari, Hiroyuki; Hanada, Masaya; Watanabe, Kazuhiro; Kashiwagi, Mieko; Kojima, Atsushi; Dairaku, Masayuki; Seki, Norikatsu; Abe, Hiroyuki; Umeda, Naotaka; Yamanaka, Haruhiko; et al.
no journal, ,
Progress on technical development on ITER and JT-60SA neutral beam injector (NBI) were reported. In development of a 1 MV insulating transformer for ITER NB power supply, a bushing extracting 1 MV required a huge insulator that was impossible to manufacture. To solve this issue, a composite bushing with FRP tube and a small condenser bushing with insulation gas was newly developed. In development the HV bushing as an insulating feed through, voltage holding in large cylindrical electrodes inside the HV bushing was investigated. The scaling for vacuum insulation design of large cylindrical electrodes was obtained. Toward long pulse production and acceleration of negative ion beam, active control system of plasma grid temperature and a new extractor consisting of the extraction grid with high water cooling capability and aperture offset were developed. As a result, 15 negative ion beam has been achieved for 100 s. Also beam energy density has been increased two orders of magnitude.
Kashiwagi, Mieko; Watanabe, Kazuhiro; Yamanaka, Haruhiko; Maejima, Tetsuya; Terunuma, Yuto*; Oda, Yuki; Tobari, Hiroyuki; Dairaku, Masayuki; Hanada, Masaya
no journal, ,
Toward the neutral beam (NB) system of ITER, the prototype of the ITER NB is under construction in the NB test facility (NBTF), Padova, Italy. For the NBTF, Japan Atomic Energy Agency manufactures, transports and constructs the 1MV high voltage power supply components to generate 1 MV, 60 A for 3600 s, which consist of fourteen components such as five DC generators and transmission lines with 100 m in a length. The manufacturing of the power supply components is in progress as scheduled. Three of five DCGs and 80% of the transmission lines have been completed. In the factory, the voltage holding test including the margin of 20% were successfully demonstrated. Then, these are under transportation to the NBTF. The construction work is started from Dec/2015 as scheduled. As the one of R&Ds results, the development of the water choke made of fiber reinforced plastic (FRP) is reported, which is the alternative of the conventional ceramic.
Yamanaka, Haruhiko; Watanabe, Kazuhiro; Kashiwagi, Mieko; Maejima, Tetsuya; Terunuma, Yuto; Umeda, Naotaka; Dairaku, Masayuki; Tobari, Hiroyuki; Hanada, Masaya
no journal, ,
no abstracts in English
