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Journal Articles

Kicker power supply for J-PARC 3-GeV RCS with SiC-MOSFET

Takayanagi, Tomohiro; Ono, Ayato; Ueno, Tomoaki*; Horino, Koki*; Togashi, Tomohito; Yamamoto, Kazami; Kinsho, Michikazu; Koizumi, Isao*; Kawamata, Shunsuke*

JPS Conference Proceedings (Internet), 33, p.011020_1 - 011020_6, 2021/03

We are developing a new kicker power supply for J-PARC 3-GeV RCS (Rapid-Cycling Synchrotron) using the next generation power semiconductor SiC-MOSFET with high withstand voltage, low loss, and superior high frequency characteristics. The three major circuits adopted for the RCS kicker power supply, the thyratron switch, the PFN circuit of coaxial cable type, and the end clipper for reflection wave absorption, has been realized with a single modular circuit board based on the LTD circuit. The new kicker power supply realizes stable operation, miniaturization and energy saving by using power semiconductors. The required high voltage can be output by stacking the 800V/2kA modular circuit board in series. The details of circuit design and the results of achieving an output of half 20kV/2kA against the target specification of 40kV/2kA are presented here.

JAEA Reports

Decommissioning activities and R&D of nuclear facilities in the second midterm plan

Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.

JAEA-Review 2016-008, 98 Pages, 2016/07

JAEA-Review-2016-008.pdf:11.73MB

Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.

Journal Articles

Operation status of the J-PARC ion source

Oguri, Hidetomo; Okoshi, Kiyonori; Ikegami, Kiyoshi*; Yamazaki, Saishun; Takagi, Akira*; Koizumi, Isao; Ueno, Akira

JPS Conference Proceedings (Internet), 8, p.011009_1 - 011009_6, 2015/09

Journal Articles

Beam test of a new radio frequency quadrupole linac for the Japan Proton Accelerator Research Complex

Kondo, Yasuhiro; Morishita, Takatoshi; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Chishiro, Etsuji; Fukuda, Shimpei; Hasegawa, Kazuo; Hirano, Koichiro; Kikuzawa, Nobuhiro; et al.

Physical Review Special Topics; Accelerators and Beams, 17(12), p.120101_1 - 120101_8, 2014/12

 Times Cited Count:6 Percentile:43.07(Physics, Nuclear)

We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.

Journal Articles

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

no abstracts in English

Journal Articles

Operation status of the J-PARC ion source

Okoshi, Kiyonori; Ikegami, Kiyoshi*; Koizumi, Isao; Ueno, Akira; Takagi, Akira*; Yamazaki, Saishun; Oguri, Hidetomo

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.946 - 949, 2014/06

A J-PARC ion source driven with a LaB6 filament is being operated without any serious trouble since the restoration from the earthquake. The H$$^{-}$$ ion current from the source is routinely restricted 19 mA for the filament lifetime. In order to increase the beam power at the linac beam operation, the beam current from the ion source was increased to 22 mA. At this operation, the filament lifetime was estimated by the reduction in the filament current. According to the steep reduction in the filament current, the break of the filament was predicted. Although the filament has broken after 10 h from the steep current reduction, the beam operation was restarted 8 h later by the preparation for the exchange of new filament. At the study time for the 3 GeV synchrotron, the ion source was operated at 30 mA for 8 days.

Journal Articles

Development of a Cs-ceeded Rf-driven H$$^{-}$$ ion source for the J-PARC

Koizumi, Isao; Ueno, Akira; Okoshi, Kiyonori; Ikegami, Kiyoshi*; Takagi, Akira*; Yamazaki, Saishun; Oguri, Hidetomo

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.920 - 923, 2014/06

In order to satisfy the J-PARC (Japan Proton Accelerator Research Complex) 2nd stage requirements the J-PARC rf-driven H$$^{-}$$ ion source is under development. The source plasma is produced by an about 50 W CW 30 MHz-rf and an about 40 kW pulsed 2 MHz-rf. The Cs is installed into the plasma chamber by opening the Cs-valve between the plasma chamber and the Cs oven, which is heated to 200$$sim$$240 $$^{circ}$$C. The H$$^{-}$$ ion beam current is maximized by optimizing the Cs quantity depending upon the Cs-valve opening time, the PE temperature depending upon the flow rate of the air through the PE cooling plate, the AMFC by the AMFC coil current, and so on. The experimental results using the plasma chamber made of copper, which satisfied the above requirements, were reported last year. The experimental results using the plasma chamber made of stainless steel are presented in this paper. The observed several interesting differences between the two plasma chambers are also presented.

Journal Articles

Dependence of beam emittance on plasma electrode temperature and rf-power, and filter-field tuning with center-gapped rod-filter magnets in J-PARC rf-driven H$$^{-}$$ ion source

Ueno, Akira; Koizumi, Isao; Okoshi, Kiyonori; Ikegami, Kiyoshi*; Takagi, Akira*; Yamazaki, Saishun; Oguri, Hidetomo

Review of Scientific Instruments, 85(2), p.02B133_1 - 02B133_5, 2014/02

 Times Cited Count:6 Percentile:29.38(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Operation status of the J-PARC ion source

Oguri, Hidetomo; Ikegami, Kiyoshi*; Okoshi, Kiyonori; Koizumi, Isao; Takagi, Akira*; Namekawa, Yuya*; Yamazaki, Saishun; Ueno, Akira

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1081 - 1083, 2013/08

no abstracts in English

Journal Articles

Development of a Cs-seeded RF-driven H$$^{-}$$ ion source for the J-PARC

Yamazaki, Saishun; Ueno, Akira; Namekawa, Yuya*; Okoshi, Kiyonori; Ikegami, Kiyoshi*; Takagi, Akira*; Koizumi, Isao; Oguri, Hidetomo

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.260 - 264, 2013/08

A cesium (Cs) seeded RF-driven H$$^{-}$$ ion source using an internal-antenna developed at the SNS (Spallation Neutron Source) is under development for the J-PARC (Japan Proton Accelerator Research Complex). The axial magnetic field optimization by using an axial magnetic field compensation (AMFC) coil significantly enhances the H$$^{-}$$ ion beam by typically 10%. An H$$^{-}$$ ion beam with a flat top duty factor of 2.5% (1 ms $$times$$ 25 Hz) of 77 mA, whose about 90% (corresponding to about 70 mA) of emittance of each direction is within 1.5 $$pi$$mm$$cdot$$mrad, is successfully extracted. During a demonstration operation over 100-hours, an H$$^{-}$$ ion beam over 66 mA was successfully produced with a relatively low RF power of about 40 kW by seeding Cs for 4-minutes a day.

JAEA Reports

Repairs crack in concrete floor at 3GeV synchrotron accelerator building

Koizumi, Isao*; Suganuma, Kazuaki

JAEA-Testing 2011-002, 223 Pages, 2011/06

JAEA-Testing-2011-002.pdf:8.22MB

3GeV synchrotron accelerator building was constructed by reinforced concrete, which is the acceleration facility at J-PARC (Japan Proton Accelerator Research Complex). 3GeV synchrotron accelerator building was built in 2005 and beam operation had been performed successfully run since 2008. I had been inspecting of each instruments since beam operation had run. In 2011, inspection list had created and carried out as inspected because of the floor crack is outstanding. This report arranges the inspection of floor crack, inspection records and repair procedures of the 3GeV synchrotron accelerator building.

JAEA Reports

None

Koizumi, Masumichi; *; Kaneko, Hiromitsu; Kishimoto, Yoichiro; Kanamori, Masashi; Ojima, Hisao; ; *

PNC TN842 83-05, 49 Pages, 1983/10

PNC-TN842-83-05.pdf:1.72MB

None

Oral presentation

Nitrogen-vacancy fluorescent centers created by ion implantations in single crystal diamond

Yamamoto, Takashi; Onoda, Shinobu; Oshima, Takeshi; Naydenov, B.*; Dolde, F.*; Fedder, H.*; Honert, J.*; Jelezko, F.*; Wrachtrup, J.*; Teraji, Tokuyuki*; et al.

no journal, , 

no abstracts in English

Oral presentation

Fabrication engineering of NV centers of controlling the dipole-dipole interactions

Onoda, Shinobu; Yamamoto, Takashi; Abe, Hiroshi; Hanaya, Hiroaki; Oshima, Takeshi; Taniguchi, Takashi*; Teraji, Tokuyuki*; Watanabe, Kenji*; Koizumi, Satoshi*; Kanda, Hisao*; et al.

no journal, , 

no abstracts in English

14 (Records 1-14 displayed on this page)
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