X ray spectroscopy on atoms (J-PARC E03, E07 and future)

Yamamoto, Takeshi; Fujita, Manami; Gogami, Toshiyuki*; Harada, Takeshi*; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Ishikawa, Yuji*; Kamata, K.*; Kanauchi, H.*; et al.

EPJ Web of Conferences, 271, p.03001_1 - 03001_5, 2022/11

https://doi.org/10.1051/epjconf/202227103001

Development of {QWR}s for the Future Upgrade of {JAEA} Tandem Superconducting Booster

Kondo, Yasuhiro; Harada, Hiroyuki; Kabumoto, Hiroshi; Kamiya, Junichiro; Matsuda, Makoto; Moriya, Katsuhiro; Tamura, Jun; Kako, Eiji*; Domae, Takeshi*; Sakai, Hiroshi*; et al.

Proceedings of 20th International Conference on RF Superconductivity (SRF 2021) (Internet), p.299 - 302, 2021/10

https://doi.org/10.18429/JACoW-SRF2021-MOPCAV015

The Japan Atomic Energy Agency (JAEA) tandem booster is one of the pioneering superconducting heavy ion linac in the world. It consists of 40 QWRs with an operation frequency of 130 MHz and , and has potential to accelerate various ions up to Au to 10 MeV/u. The user operation was started in 1994, however, it has been suspended since the Great East Japan Earthquake in 2011. Recently, in addition to the efforts to restart the tandem booster, activities to develop new lower-beta cavities to improve the acceleration efficiency of heavier ions such as Uranium has been launched. In this work, the current status of the design study of the QWRS for the JAEA tandem facility is presented. Electro-magnetic design using simulation code was performed and acceleration gradient of 5.7 MV/m and 6.6 MV/m was obtained for 130-MHz and 65-MHz QWRs, respectively.

The Energy-resolved neutron imaging system, RADEN

Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi; Nakatani, Takeshi; Segawa, Mariko; Hiroi, Kosuke; Su, Y. H.; Oi, Motoki; Harada, Masahide; Iikura, Hiroshi; et al.

Review of Scientific Instruments, 91(4), p.043302_1 - 043302_20, 2020/04

https://doi.org/10.1063/1.5136034

Theoretical elucidation of space charge effects on the coupled-bunch instability at the 3 GeV Rapid Cycling Synchrotron at the Japan Proton Accelerator Research Complex

Shobuda, Yoshihiro; Chin, Y. H.*; Saha, P. K.; Hotchi, Hideaki; Harada, Hiroyuki; Irie, Yoshiro*; Tamura, Fumihiko; Tani, Norio; Toyama, Takeshi*; Watanabe, Yasuhiro; et al.

Progress of Theoretical and Experimental Physics (Internet), 2017(1), p.013G01_1 - 013G01_39, 2017/01

AA2016-0375.pdf:3.07MB

https://doi.org/10.1093/ptep/ptw169

The Rapid Cycling Synchrotron (RCS), whose beam energy ranges from 400 MeV to 3 GeV and which is located in the Japan Proton Accelerator Research Complex, is a kicker-impedance dominant machine, which violates the impedance budget from a classical viewpoint. Contrary to conventional understanding, we have succeeded to accelerate a 1-MW equivalent beam. The machine has some interesting features: for instance, the beam tends to be unstable for the smaller transverse beam size, the beam is stabilized by increasing the peak current . Space charge effects play an important role in the beam instability at the RCS. In this study, a new theory has been developed to calculate the beam growth rate with the head-tail and coupled-bunch modes () while taking space charge effects into account. The theory sufficiently explains the distinctive features of the beam instabilities at the RCS.

Correlation between intermolecular hydrogen bonds and melting points of uranyl nitrate complexes with cyclic urea derivatives

Suzuki, Tomoya; Takao, Koichiro*; Kawasaki, Takeshi*; Harada, Masayuki*; Nogami, Masanobu*; Ikeda, Yasuhisa*

Polyhedron, 96, p.102 - 106, 2015/08

https://doi.org/10.1016/j.poly.2015.04.034

We have determined crystal structures of UO(NO)() (: 2-imidazolidone), UO(NO)() (: tetrahydro-2-pyrimidone) and UO(NO)() (: 1-methyl-2-imidazolidone) by using single crystal X-ray analysis, and examined correlations between melting points (mps) and intermolecular hydrogen bonds (HBs) of UO(NO)(CU) (CU: cyclic urea derivatives) and UO(NO)(NRP) (NRP: pyrrolidone derivative).

Beam instrumentation at the 1 MW Proton beam of J-PARC RCS

Yamamoto, Kazami; Hayashi, Naoki; Okabe, Kota; Harada, Hiroyuki; Saha, P. K.; Yoshimoto, Masahiro; Hatakeyama, Shuichiro; Hotchi, Hideaki; Hashimoto, Yoshinori*; Toyama, Takeshi*

Proceedings of 54th ICFA Advanced Beam Dynamics Workshop on High-Intensity, High Brightness and High Power Hadron Beams (HB 2014) (Internet), p.278 - 282, 2015/03

http://epaper.kek.jp/HB2014/papers/weo2ab03.pdf

http://epaper.kek.jp/HB2014/talks/weo2ab03_talk.pdf

Rapid Cycling Synchrotron (RCS) of Japan Proton Accelerator Complex (J-PARC) is providing more than 300 kW of proton beam to Material and Life science Facility (MLF) and Main Ring (MR). Last summer shutdown, a new ion source was installed to increase output power to 1 MW. In order to achieve reliable operation of 1 MW, we need to reduce beam loss as well. Beam quality of such higher output power is also important for users. Therefore we developed new monitors that can measure the halo with higher accuracy. We present beam monitor systems for these purposes.

C-face interface defects in 4H-SiC MOSFETs studied by electrically detected magnetic resonance

Umeda, Takahide*; Okamoto, Mitsuo*; Arai, Ryo*; Sato, Yoshihiro*; Kosugi, Ryoji*; Harada, Shinsuke*; Okumura, Hajime*; Makino, Takahiro; Oshima, Takeshi

Materials Science Forum, 778-780, p.414 - 417, 2014/02

https://doi.org/10.4028/www.scientific.net/MSF.778-780.414

Interface defects of Metal-Oxide-Semiconductors (MOSFETs) fabricated on Carbone (C) face 4H-SiC were investigated by Electrically Detected Magnet Resistance (EDMR). Gate oxide of the MOSFETs was formed by either wet-oxidation and H annealing or dry-oxidation. The values of channel mobility for MOSFETS with wet gate oxide and dry gate oxide are less than 1 and 90 cm/Vs, respectively. By EDMR measurement under low temperature (less than 20 K), EDMR signals related to C were detected. The peak height of the signals increased with increasing -ray doses, and the channel mobility decreased. From this result, it is assumed that hydrogen atoms passivating C dangling bonds are released by -rays and the channel mobility decreases with increasing the C related defects.

Stability of polyvinylpolypyrrolidone against -ray irradiation in HNO media

Nogami, Masanobu*; Sugiyama, Yuichi*; Kawasaki, Takeshi*; Harada, Masayuki*; Kawata, Yoshihisa*; Morita, Yasuji; Kikuchi, Toshiaki*; Ikeda, Yasuhisa*

Journal of Radioanalytical and Nuclear Chemistry, 296(1), p.423 - 427, 2013/04

https://doi.org/10.1007/s10967-012-2121-3

Stability of polyvinylpolypyrrolidone (PVPP), a resin with adsorption selectivity to U(VI) in nitric acid media, against -ray irradiation has been examined using HNO solutions of various concentrations. As the result, no clear decrease in the capacity was observed for any samples. Or rather, it was found that the capacity increased by approximately 50% for the PVPP slurry irradiated in 6 M HNO. The infrared spectroscopic study indicates that PVPP degrades by -ray irradiation in HNO from the cleavage of the pyrrolidone ring by the addition of oxygen atom originating from HNO, followed by the formation of chain monoamides with multiple coordinative atoms by the continuous addition of oxygen, finally leading to the generation of primary-amine type anion exchange resin. It is also indicated that all generated functional groups possess adsorptivity to U(VI) in 3 M HNO.

Development of remote controlled electron probe micro analyzer with crystal orientation analyzer

Honda, Junichi; Matsui, Hiroki; Harada, Akio; Obata, Hiroki; Tomita, Takeshi

JAEA-Technology 2012-022, 35 Pages, 2012/07

JAEA-Technology-2012-022.pdf:3.58MB

The advanced utilization of Light Water Reactor (LWR) fuel is progressed in Japan to save the power generating cost and the volume of nuclear wastes. The electric power companies have been continued the approach to extend the burnup and to rise up the thermal power of the commercial fuel. The government should be accumulating the detailed information of the newest technologies to make the regulations and guidelines for the safety of the advanced nuclear fuels. The remote controlled Electron Prove Micro Analyzer attached with crystal orientation analyzer (EPMA) has been developed in Japan Atomic Energy Agency (JAEA) to evaluate the fuel behavior effected by the cladding microstructure under the accident condition. The device was modified to the airtight and earthquake resistant structure for the examination of high radioactive elements. This paper describes the specification of EPMA and the test results of the cold mock-up to confirm their performances and reliabilities.

Status of injection energy upgrade for J-PARC RCS

Hayashi, Naoki; Harada, Hiroyuki; Hotchi, Hideaki; Kamiya, Junichiro; Saha, P. K.; Shobuda, Yoshihiro; Takayanagi, Tomohiro; Tani, Norio; Yamamoto, Kazami; Yamamoto, Masanobu; et al.

Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.3921 - 3923, 2012/05

http://accelconf.web.cern.ch/accelconf/IPAC2012/papers/thppp081.pdf

The injection energy upgrade from 181 to 400 MeV for J-PARC RCS is planned in 2013. One power supply was replaced and using for a normal operation. An IGBT chopper type power supply which has larger switching noise will be changed to a capacitor bank type. New injection system allows the center injection with 400 MeV and switching painting area. As further steps for the leakage field, it begins to diminish the effect from the beam transport line. A quadrupole corrector system is designed and fabricated to compensate the beta beat due to the injection bump as the first step. Two profile monitors will be modified to correct position systematic errors and third one is going to be installed at dispersion free section. It is important to minimize kicker impedance lower, which may cause the beam instability. A diode, which has high reverse breakdown voltage and works with lower forward voltage, has been developed. Using this new diode, an experiment shows the impedance becomes lower.