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Tomita, Ryohei; Tomita, Jumpei; Suzuki, Daisuke; Miyamoto, Yutaka; Yasuda, Kenichiro
Journal of Nuclear Science and Technology, 10 Pages, 2025/05
A new automated particle measurement (APM) combined with micromanipulation using large geometry secondary ion mass spectrometry instrument was proposed and demonstrated to remove the particle mixing effect, which indicated that the aggregation of uranium particles was detected as a single uranium particle, from APM results. The results showed that the new APM method was more effective than the traditional APM method in removing the particle mixing effect from the APM results and determining the existence of minor uranium isotopes in the samples.
U/
U isotopic analysis of trace uranium in safeguards environmental samples using multicollector inductively coupled plasma mass spectrometryTomita, Jumpei; Tomita, Ryohei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka
Journal of the American Society for Mass Spectrometry, 35(6), p.1178 - 1183, 2024/05
Times Cited Count：0 Percentile：0.00(Biochemical Research Methods)A sensitive analytical technique was investigated in order to determine 10
order of U/U ratio in the sub-ng of uranium using a multi-collector ICP-MS. First, the solution volume was concentrated to one tenth to obtain higher intensities. Next, data acquisition was started from the beginning of the solution uptake and continued until all solution was exhausted. Taking advantage of multi-collector measurement, all data were used with excepting the portion affected by air mixing at the beginning and end of sample introduction. The isotope ratios were calculated from the total counts of each isotope. This technique was applied to U isotope standard (IRMM-184) to measure the 10 order of U/U ratio in the sub-ng of uranium. Measured values were in good agreement with the certified value within the uncertainity (
=2). The uncertainties obtained with this new technique (32% on average) were revised to be 10 times smaller than those obtained with the conventionalmethod.
Funakoshi, Tomomasa; Watanabe, So; Arai, Yoichi; Iwamoto, Toshihiro; Watanabe, Masayuki; Nishimoto, Yoshihiro*; Yasuda, Makoto*
Mechanical Engineering Journal (Internet), 11(2), p.23-00445_1 - 23-00445_7, 2024/04
Linh, B. D.*; Corsi, A.*; Gillibert, A.*; Obertelli, A.*; Doornenbal, P.*; Barbieri, C.*; Duguet, T.*; G
mez-Ramos, M.*; Holt, J. D.*; Hu, B. S.*; et al.
Physical Review C, 109(3), p.034312_1 - 034312_15, 2024/03
Times Cited Count：2 Percentile：74.11(Physics, Nuclear)no abstracts in English
Yasuda, Hiroshi*; Saito, Tatsuo; Fumoto, Hiromichi*; Sugawara, Shinetsu*; Tsuchida, Shoji*; Kasai, Atsushi*; Furuta, Sadaaki*
Hoken Butsuri (Internet), 58(3), p.120 - 134, 2023/11
This paper is a summary of the activity report of the specialized study group of the Japan Health Physics Society on handling of naturally occurring radioactive wastes from humanities and social sciences perspective. To ensure the reliability of the long-term assessment, this special committee first reviews options for disposal of uranium waste depending on its concentration, especially those adopted or considered in Japan and overseas (U.S.A., U.K.) for uranium concentrations exceeding a sufficiently small amount of uranium (an average of 1 Bq/g of the sum of 
U, 
U, and U).
Be ground-state molecular structure using Be(
)
He triple differential reaction cross-section measurementsLi, P. J.*; Beaumel, D.*; Lee, J.*; Assi
, M.*; Chen, S.*; Franchoo, S.*; Gibelin, J.*; Hammache, F.*; Harada, T.*; Kanada-En'yo, Yoshiko*; et al.
Physical Review Letters, 131(21), p.212501_1 - 212501_7, 2023/11
Times Cited Count：21 Percentile：94.59(Physics, Multidisciplinary)The cluster structure of the neutron-rich isotope Be has been probed via the () reaction. The triple differential cross-section was extracted and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using the Tohsaki-Horiuchi-Schuck-R
pke wave function and the wave function deduced from Antisymmetrized Molecular Dynamics calculations. The remarkable agreement between calculated and measured cross-sections in both shape and magnitude validates the description of the Be ground-state as a rather compact nuclear molecule.
Yasuda, Yosuke*; Matsumoto, Yoshihiro*; Shinohara, Takenao; Nabeshima, Fumika*; Horiuchi, Keisuke*; Nagai, Hiroki*
International Journal of Heat and Mass Transfer, 213, p.124291_1 - 124291_2, 2023/10
Times Cited Count：1 Percentile：91.18(Thermodynamics)Hirano, Tatsumi*; Maeda, Takehiro*; Murata, Tetsuyuki*; Yamamoto, Takahiro*; Matsubara, Eiichiro*; Shobu, Takahisa; Shiro, Ayumi*; Yasuda, Ryo*; Takamatsu, Daiko*
SPring-8/SACLA Riyo Kenkyu Seikashu (Internet), 11(5), p.345 - 353, 2023/10
no abstracts in English
Tomita, Ryohei; Tomita, Jumpei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka
Hosha Kagaku, (48), p.1 - 15, 2023/09
Secondary Ion Mass Spectrometry (SIMS) is the method to detect secondary ions produced by the sputtering of primary ions. SIMS is one of effective method to measure isotopic composition of particles containing nuclear material in environmental sample for safeguards. We are a group member of the International Atomic Energy Agency (IAEA)'s network of analytical laboratories and have developed analytical techniques using SIMS and other mass spectrometers for nuclear safeguards. We will introduce the principle of SIMS and analytical techniques developed by our group to measure isotopic composition of uranium particles which having a particle diameter of micron order in environmental sample for safeguards.
OKondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
Times Cited Count：29 Percentile：95.28(Multidisciplinary Sciences)no abstracts in English
Ca cast doubt on a doubly magic 
CaChen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Chazono, Yoshiki*; Hagen, G.*; Holt, J. D.*; et al.
Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08
Times Cited Count：9 Percentile：89.00(Astronomy & Astrophysics)Gamma decays were observed in 
Ca and 
Ca following quasi-free one-proton knockout reactions from 
Sc. For Ca, a 
ray transition was measured to be 1456(12) keV, while for Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 
decays. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 
level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 
and 
orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic Ca and potentially drives the dripline of Ca isotopes to 
Ca or even beyond.
Ne at the transition into the island of inversion; Detailed structure study of NeWang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
Times Cited Count：4 Percentile：67.28(Astronomy & Astrophysics)Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.
Miyamoto, Yutaka; Suzuki, Daisuke; Tomita, Ryohei; Tomita, Jumpei; Yasuda, Kenichiro
Isotope News, (786), p.22 - 25, 2023/04
no abstracts in English
Hirano, Tatsumi*; Maeda, Takehiro*; Murata, Tetsuyuki*; Yamaki, Takahiro*; Matsubara, Eiichiro*; Shobu, Takahisa; Shiro, Ayumi*; Yasuda, Ryo*; Takamatsu, Daiko*
SPring-8/SACLA Riyo Kenkyu Seikashu (Internet), 11(1), p.49 - 57, 2023/02
island of inversion; First study of low-lying bound excited states in 
V and 
VElekes, Z.*; Juh
sz, M. M.*; Sohler, D.*; Sieja, K.*; Yoshida, Kazuki; Ogata, Kazuyuki*; Doornenbal, P.*; Obertelli, A.*; Achouri, N. L.*; Baba, Hidetada*; et al.
Physical Review C, 106(6), p.064321_1 - 064321_10, 2022/12
Times Cited Count：3 Percentile：43.00(Physics, Nuclear)The low-lying level structure of V and V was investigated for the first time. The neutron knockout reaction and inelastic proton scattering were applied for V while the neutron knock-out reaction provided the data for V. Four and five new transitions were determined for V and V, respectively. Based on the comparison to our shell-model calculations using the Lenzi-Nowacki-Poves-Sieja (LNPS) interaction, three of the observed rays for each isotope could be placed in the level scheme and assigned to the decay of the first 11/2
and 9/2 levels. The (
,
) excitation cross sections for V were analyzed by the coupled-channels formalism assuming quadrupole plus hexadecapole deformations. Due to the role of the hexadecapole deformation, V could not be unambiguously placed on the island of inversion.
neutron orbital and the 
shell closure in 
CaEnciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; Ogata, Kazuyuki*; Poves, A.*; Yoshida, Kazuki; Achouri, N. L.*; Baba, Hidetada*; et al.
Physical Review Letters, 129(26), p.262501_1 - 262501_7, 2022/12
Times Cited Count：18 Percentile：86.28(Physics, Multidisciplinary)The one-neutron knockout from Ca was performed at 
230 MeV/nucleon combined with prompt spectroscopy. The momentum distributions corresponding to the removal of 
and 
neutrons were measured. The cross sections are consistent with a shell closure at the neutron number , found as strong as at 
and 
in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron 
and orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.
Tomita, Ryohei; Tomita, Jumpei; Yomogida, Takumi; Suzuki, Daisuke; Yasuda, Kenichiro; Esaka, Fumitaka; Miyamoto, Yutaka
KEK Proceedings 2022-2, p.108 - 113, 2022/11
Automated Particle Measurement (APM) is the first measurement of environmental sample for safeguard purpose. APM tells us the number of particles in sample, their enrichment and their location. Precision and accuracy of APM is easily affected by particle condition. We have investigated how influential baking temperature in sample preparation are for uranium secondary ion quantity, uranium hydride generation and particle crystallinity. Our experimental results showed that baking temperature of 800
C reduced uranium secondary ion quantity to 33% compared with baking at 350C. Uranium hydride generation ratio of the sample baked at 850C was also 4 times higher than the sample baked at 350C. Baking at 850C raised only crystallinity of uranium particles. Baking sample at too high temperature caused less uranium secondary ion generation and much more uranium hydride generation. It made precision and accuracy of APM worse. In our experiment, baking at 350C is suitable for uranium particles in the safeguards sample.
Tomita, Jumpei; Tomita, Ryohei; Suzuki, Daisuke; Yasuda, Kenichiro; Miyamoto, Yutaka
KEK Proceedings 2022-2, p.154 - 158, 2022/11
Precise determination of minor U isotopes (
U and U) of particles from the safeguard environmental samples is powerful method for detecting the undeclared nuclear activities. In this study, preparation method of U particle was examined to utilize for the minor U isotope determination. The porous silica particles were used as the particle matrix and lutetium was mixed to the impregnation solution as U impregnation indicator for the particle picking. The result of the Scanning Electron Microscope indicated that the contacting the solution with Si particles overnight gently could produce the impregnated particles effectively rather than the mixing them with PFA stick.
Takeuchi, Yusuke*; Tojo, Junji*; Yamanaka, T.*; Nakazawa, Yuga*; Iinuma, Hiromi*; Kondo, Yasuhiro; Kitamura, Ryo; Morishita, Takatoshi; Cicek, E.*; Ego, Hiroyasu*; et al.
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.562 - 564, 2022/10
A muon linac is under development for future muon g-2/EDM experiments at J-PARC. The linac provides a 212 MeV muon beam to an MRI-type compact storage ring. After the initial acceleration using the electrostatic field created by mesh and cylindrical electrodes, the muons are accelerated using four types of radio-frequency accelerators. To validate the linac design as a whole, end-to-end simulations were performed using General Particle Tracer. In addition, error studies were performed to investigate the effects on beam and spin dynamics of various errors in the accelerator components and input beam distribution. This paper describes the results of the end-to-end simulations and error studies.
Nakazawa, Yuga*; Iinuma, Hiromi*; Iwata, Yoshiyuki*; Cicek, E.*; Ego, Hiroyasu*; Futatsukawa, Kenta*; Kawamura, Naritoshi*; Mibe, Tsutomu*; Mizobata, Satoshi*; Otani, Masashi*; et al.
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.275 - 278, 2022/09
We conducted a high-power test of a prototype cavity of a 324-MHz inter-digital H-mode drift tube linac (IH-DTL) for the muon g-2/EDM experiment at J-PARC. This prototype cavity (short-IH) was developed to verify the fabrication methodology for the full-length IH cavity with a monolithic DT structure. After 40 h of conditioning, the short-IH has been stably operated with an RF power of 88 kW, which corresponds to 10% higher accelerating field than the design field (E0) of 3.0 MV/m. In addition, the thermal characteristics and frequency response were measured, verifying that the experimental data was consistent with the three-dimensional model. In this paper, the high-power tests of this IH-DTL for muon acceleration are described.
