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-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samplesLi, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count：2 Percentile：31.9(Chemistry, Analytical)no abstracts in English
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：43 Percentile：96.93(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Moriya, Katsuhiro; Kawane, Yusuke*; Miura, Akihiko; Futatsukawa, Kenta*; Miyao, Tomoaki*
Journal of Physics; Conference Series, 1067, p.072009_1 - 072009_3, 2018/09
Times Cited Count：0 Percentile：0.11(Physics, Particles & Fields)no abstracts in English
Kamiya, Junichiro; Ogiwara, Norio*; Miura, Akihiko; Kinsho, Michikazu; Hikichi, Yusuke*
Journal of Physics; Conference Series, 1067, p.072006_1 - 072006_6, 2018/09
Times Cited Count：2 Percentile：68.25(Physics, Particles & Fields)A beam profile monitor using interaction between the beam and the gas molecules distributed in sheet shape has been developed. Ions or luminescence generated by passing the beam through the gas sheet has the information of cross-section shape of the beam. The gas sheet beam monitor will become a useful tool to measure the profile of high power beams because it has no breakable element such as wires. Furthermore, 2-D beam profile can be obtaine at a certain position of beam line. We applied the gas-sheet based beam profile monitor to J-PARC LINAC, where the negative hydrogen atoms are accelerated to the energy of 400 MeV. The vacuum system was carefully designed not to make an unacceptable pressure rise in nearby cavities when the gas was injected. The clear image of the beam profile was successfully obtained by detecting the ionized N gas.
Miura, Akihiko; Kawane, Yusuke*; Moriya, Katsuhiro; Futatsukawa, Kenta*; Miyao, Tomoaki*; Fukuoka, Shota*
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.2183 - 2186, 2018/06
In order to mitigate the beam loss during a beam transportation in the high-brilliant accelerator facilities, wire-based profile monitors are used to measure by both transverse and longitudinal beam profiles using wire-scanner monitors and bunch-shape monitors for the tuning of quadrupole magnets and buncher cavities. Signals are generated due to the direct interaction between a metallic wire and beam. We have used the tungsten wire as a high melting-point material by estimation of heat loading during the impact of beam particles. In addition, a spring is applied for the relaxing a flexure under wire's own weight. A tensile fracture test is conducted by supplying an electrical current as a simulated beam loading. As the results, we obtained the relation between the thermal limit to fracture and tension loading of tungsten wire.
Miura, Akihiko; Fukuoka, Shota*; Miyao, Tomoaki*; Kawane, Yusuke*; Futatsukawa, Kenta*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.560 - 562, 2017/12
no abstracts in English
Kondo, Yasuhiro; Asano, Hiroyuki*; Chishiro, Etsuji; Hirano, Koichiro; Ishiyama, Tatsuya; Ito, Takashi; Kawane, Yusuke; Kikuzawa, Nobuhiro; Meigo, Shinichiro; Miura, Akihiko; et al.
Proceedings of 28th International Linear Accelerator Conference (LINAC 2016) (Internet), p.298 - 300, 2017/05
We have constructed a linac for development of various accelerator components at J-PARC. The ion source is same as the J-PARC linac's, and the RFQ is a used one in the J-PARC linac. The beam energy is 3 MeV and nominal beam current is 30 mA. The accelerator has been already commissioned, and the first development program, laser-charge-exchange experiment for the transmutation experimental facility, has been started. In this paper, present status of this 3-MeV linac is presented.
Hirano, Koichiro; Asano, Hiroyuki; Ishiyama, Tatsuya; Ito, Takashi; Okoshi, Kiyonori; Oguri, Hidetomo; Kondo, Yasuhiro; Kawane, Yusuke; Kikuzawa, Nobuhiro; Sato, Yoshikatsu; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.310 - 313, 2016/11
We have used a beam scraper with the incident angle of 65deg to reduce the beam power deposition density in the MEBT between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC linac. The 65 scraper was irradiated by the H
beam up to particle number of 1.47E22. We observed a lot of surface projections with several hundred micrometers high in the beam irradiation damage on the scraper by using the laser microscope. In order to study the limits of scrapers, we constructed a new 3 MeV linac at J-PARC. We will conduct the scraper irradiation test at the end of this year.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Miura, Akihiko; Maruta, Tomofumi*; Liu, Y.*; Miyao, Tomoaki*; Kawane, Yusuke; Ouchi, Nobuo; Oguri, Hidetomo; Ikegami, Masanori*; Hasegawa, Kazuo
JPS Conference Proceedings (Internet), 8, p.011002_1 - 011002_6, 2015/09
In the J-PARC Linac, an energy upgrade project has started since 2009 using Annular-ring Coupled Structure cavities to achieve design beam power of 1 MW at the exit of the downstream rapid cycling synchrotron. Linac beam parameters of the upgraded Linac is drastically improved especially for the beam energy from 181 to 400 MeV in the project. To meet with the significant upgrades of the Linac, beam monitors to be used for the upgraded beam line are newly designed and fabricated as well as the beam monitor layout is designed with the consideration to the beam commissioning strategies. This paper introduces the beam monitor layout in the new beam line and the commissioning results to confirm the beam monitor functioning.
Miyao, Tomoaki*; Miura, Akihiko; Kawane, Yusuke; Tamura, Jun; Nemoto, Yasuo; Ao, Hiroyuki*; Hayashi, Naoki; Oguri, Hidetomo; Ouchi, Nobuo; Mayama, Minoru*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1338 - 1341, 2015/09
no abstracts in English
Futatsukawa, Kenta*; Kawane, Yusuke; Tamura, Jun; Nemoto, Yasuo; Hayashi, Naoki; Fukuoka, Shota*; Mayama, Minoru*; Miura, Akihiko; Miyao, Tomoaki*
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1246 - 1250, 2015/09
no abstracts in English
Hirano, Koichiro; Kondo, Yasuhiro; Kawane, Yusuke; Shinozaki, Shinichi; Miura, Akihiko; Morishita, Takatoshi; Sawabe, Yuki; Sugimura, Takashi*; Naito, Fujio*; Fang, Z.*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.944 - 947, 2015/09
Two RF-deflecting cavities as a chopper and a beam scraper have been used in the MEBT1 between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC Linac. We replaced with a newly fabricated RF chopper to decrease beam loss for the operation with 50 mA. We installed two new scrapers to absorb the higher power of the deflected beam by the RF chopper. This paper describes the RF chopper system and beam irradiation test results of the scraper.
C level structure by 
-ray spectroscopyHosomi, Kenji; Ma, Y.*; Ajimura, Shuhei*; Aoki, Kanae*; Dairaku, Seishi*; Fu, Y.*; Fujioka, Hiroyuki*; Futatsukawa, Kenta*; Imoto, Wataru*; Kakiguchi, Yutaka*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2015(8), p.081D01_1 - 081D01_8, 2015/08
Times Cited Count：14 Percentile：66.59(Physics, Multidisciplinary)Level structure of the C hypernucleus was precisely determined by means of -ray spectroscopy. We identified four -ray transitions via the 
C
reaction using a germanium detector array, Hyperball2. The spacing of the ground-state doublet 
was measured to be 
(stat)
(syst)keV from the direct 
transition. Excitation energies of the 
and 
states were measured to be 
, keV and 
, keV, respectively. The obtained level energies provide definitive references for the reaction spectroscopy of 
hypernuclei.
Miura, Akihiko; Kawane, Yusuke; Ouchi, Nobuo; Miyao, Tomoaki*
Proceedings of 3rd International Beam Instrumentation Conference (IBIC 2014) (Internet), p.430 - 434, 2015/04
Bunch shape monitors (BSMs) have been developed and installed in the summer of 2012 at the beginning of new Annular-ring Coupled Structure Linac (ACS) section. Because a problem of the vacuum degradation was found during the BSM operations, BSMs were once dismounted from the beam line and the off-line baking operations with outgas analysis had been performed to reduce the vacuum pressure of BSM surrounding. The impacts of the bias voltage to the target wire and static lens, and the RF power to the deflector were examined in the vacuum test. Finally, we propose the additional vacuum system arrangement for the installation of BSM to the beam line. This paper describes the vacuum test results of BSMs and the additional vacuum system arrangement for the BSM installation.
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
Miyao, Tomoaki*; Miura, Akihiko; Kawane, Yusuke*; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.718 - 720, 2014/10
The beam energy of the J-PARC Linac is calculated by TOF (Time-of-Flight) method with the flight distance and the beam phases measured at the two phase monitors. Because the accuracy of the beam energy calculation is directly depending on the errors in the phase measurement system, all beam phase monitors are calibrated annually. We have decided to use an IQ modulator circuit to realize the high accurate calibration and to reduce the calibration time. We describe the original and new procedure of the energy calculation in this paper.
Kawane, Yusuke*; Miura, Akihiko; Miyao, Tomoaki*; Hirano, Koichiro; Sugimura, Takashi*; Kato, Yuko; Sawabe, Yuki; Fukuda, Shimpei; Ouchi, Nobuo
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1288 - 1291, 2014/10
In the J-PARC Linac, because an upgrading of a beam current up to 50mA using an RF-driven ion source and a new RFQ Linac cavity is in progress, we have developed a new frontend equipments. In order to protect the scraper against 50 mA, we need to observe the temperature and to avoid the excess heat loading of the scraper surface and to count the irradiated beam particles. We also monitor the beam transmission between the upstream and downstream of the chopper cavity to check the chopping errors using the beam current monitors. We fabricated the interlock system for the temperature, irradiated particle numbers and beam transmission. And we tested them in the test stand with actual beam. This paper describes the interlock system and their test results.
and EuAlNakamura, Ai*; Hiranaka, Yuichi*; Hedo, Masato*; Nakama, Takao*; Miura, Yasunao*; Tsutsumi, Hiroki*; Mori, Akinobu*; Ishida, Kazuhiro*; Mitamura, Katsuya*; Hirose, Yusuke*; et al.
JPS Conference Proceedings (Internet), 3, p.011012_1 - 011012_6, 2014/06
Nakamura, Ai*; Hiranaka, Yuichi*; Hedo, Masato*; Nakama, Takao*; Tatetsu, Yasutomi*; Maehira, Takahiro*; Miura, Yasunao*; Mori, Akinobu*; Tsutsumi, Hiroki*; Hirose, Yusuke*; et al.
Journal of the Physical Society of Japan, 82(12), p.124708_1 - 124708_6, 2013/12
Times Cited Count：21 Percentile：72.6(Physics, Multidisciplinary)
