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Journal Articles

Fetal and maternal atomic bomb survivor dosimetry using the J45 pregnant female phantom series; Considerations of the kneeling and lying posture with comparisons to the DS02 system

Domal, S. J.*; Correa-Alfonso, C. M.*; Paulbeck, C. J.*; Griffin, K. T.*; Sato, Tatsuhiko; Funamoto, Sachiyo*; Cullings, H. M.*; Egbert, S. D.*; Endo, Akira; Hertel, N. E.*; et al.

Health Physics, 125(4), p.245 - 259, 2023/10

The RERF Working Group on Organ Dose (WGOD) has established the J45 (Japan 1945) series of high-resolution voxel phantoms, which were derived from the UF/NCI series of hybrid phantoms and scaled to match mid-1940s Japanese body morphometries. In this present study, we present the J45 pregnant female phantoms in both a kneeling and lying posture, and assess the dosimetric impact of these more anatomically realistic survivor models in comparisons to current organ doses given by the DS02 system. For the kneeling phantoms facing the bomb hypocenter, organ doses from bomb source photon spectra were shown to be overestimated by the DS02 system by up to a factor of 1.45 for certain fetal organs and up to a factor of 1.17 for maternal organs. For lying phantoms with their feet in the direction of the hypocenter, fetal organ doses from bomb source photon spectra were underestimated by the DS02 system by factors as low as 0.77 while maternal organ doses were overestimated by up to a factor of 1.38. Results from this study highlight the degree to which the existing DS02 system can differ from organ dosimetry based upon 3D radiation transport simulations using more anatomically realistic models of those survivors exposed during pregnancy while in a kneeling or lying position.

Journal Articles

First observation of $$^{28}$$O

Kondo, 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

no abstracts in English

Journal Articles

Intruder configurations in $$^{29}$$Ne at the transition into the island of inversion; Detailed structure study of $$^{28}$$Ne

Wang, 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

Detailed $$gamma$$-ray spectroscopy of the exotic neon isotope $$^{28}$$Ne has been performed using the one-neutron removal reaction from $$^{29}$$Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for $$^{28}$$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.

Journal Articles

Fetal atomic bomb survivor dosimetry using the J45 series of pregnant female phantoms with realistic survivor exposure scenarios; Comparisons to dose estimates in the DS02 system

Paulbeck, C. J.*; Sato, Tatsuhiko; Funamoto, Sachiyo*; Lee, C.*; Griffin, K. T.*; Cullings, H. M.*; Egbert, S. D.*; Endo, Akira; Hertel, N. E.*; Bolch, W. E.*

Radiation and Environmental Biophysics, 62(3), p.317 - 329, 2023/08

 Times Cited Count:0 Percentile:0.01(Biology)

In our prior study [Radiat Res 192, 538-561 (2019)], we presented a new J45 (Japanese 1945) series of high-resolution phantoms of the adult pregnant female at 8-week, 15-week, 25-week, and 38-week post-conception. In this present study, we extend this work using realistic angular fluences from the DS02 system for up to nine different radiation categories and five shielding conditions. General findings are that the current DS02 fetal dose surrogate overestimates values of fetal organ dose seen in the J45 phantoms towards the cranial end of the fetus, especially in the later stages of pregnancy. This work supports our previous findings that the J45 pregnant female phantom series offers significate opportunities for gestational age-dependent assessment of fetal organ dose without the need to invoke the uterine wall as a fetal organ surrogate.

Journal Articles

Multiple mechanisms in proton-induced nucleon removal at $$sim$$100 MeV/nucleon

Pohl, T.*; Sun, Y. L.*; Obertelli, A.*; Lee, J.*; G$'o$mez-Ramos, M.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Cai, B. S.*; Yuan, C. X.*; Brown, B. A.*; et al.

Physical Review Letters, 130(17), p.172501_1 - 172501_8, 2023/04

 Times Cited Count:2 Percentile:90.46(Physics, Multidisciplinary)

We report on the first proton-induced single proton- and neutron-removal reactions from the neutron deficient $$^{14}$$O nucleus with large Fermi-surface asymmetry at $$sim$$100 MeV/nucleon. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively.

Journal Articles

Modelling oxygen effects on the in- and out-of-field radiosensitivity of cells exposed to intensity-modulated radiation fields

Matsuya, Yusuke; McMahon, S. J.*; Butterworth, K. T.*; Yachi, Yoshie*; Saga, Ryo*; Sato, Tatsuhiko; Prise, K. M.*

Physics in Medicine & Biology, 68(9), p.095008_1 - 095008_12, 2023/04

 Times Cited Count:0 Percentile:68.8(Engineering, Biomedical)

Hypoxia induces radioresistance in tumors, leading to malignant progression in intensity-modulated radiation therapy. To date, it has been shown that intercellular signalling between cells positioned inside and outside radiation field impacts on cellular radiosensitivity under hypoxia and normoxia. However, the mechanistic role of intercellular communication in hypoxia remains to be fully understood. In this study, we modelled the cell-killing effects of intercellular signalling in hypoxia to better understand the underlying mechanisms of response. We used the oxygen enhancement ratio (OER) given from early DSB yields and modelled the in- and out-of-field radiosensitivity. As a result, the model analysis provides an mechanistical interpretation that the probability of hits for releasing cell-killing signals is dependent on oxygen. Our data also suggested that the field-type independent OER value, which can be given by uniform-field exposure, can be applied when predicting both in- and out-of-field radiosensitivity. These results would contribute to more precise understanding of intercellular signalling under heterogeneous exposure to intensity-modulated radiation fields.

Journal Articles

The Experimental and simulation results of LIVE-J2 test; Investigation on heat transfer in a solid-liquid mixture pool

Madokoro, Hiroshi; Yamashita, Takuya; Gaus-Liu, X.*; Cron, T.*; Fluhrer, B.*; Sato, Ikken; Mizokami, Shinya*

Nuclear Technology, 209(2), p.144 - 168, 2023/02

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

Journal Articles

New $$K$$ isomers in $$^{248}$$Cf

Orlandi, R.; Makii, Hiroyuki; Nishio, Katsuhisa; Hirose, Kentaro; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Ito, Yuta; Suzaki, Fumi; Nagame, Yuichiro*; et al.

Physical Review C, 106(6), p.064301_1 - 064301_11, 2022/12

 Times Cited Count:0 Percentile:0.02(Physics, Nuclear)

Journal Articles

Modeling the transport and deposition of $$^{10}$$Be produced by the strongest solar proton event during the holocene

Spiegl, T. C.*; Yoden, Shigeo*; Langematz, U.*; Sato, Tatsuhiko; Chhin, R.*; Noda, Satoshi*; Miyake, Fusa*; Kusano, Kanya*; Schaar, K.*; Kunze, M.*

Journal of Geophysical Research; Atmospheres, 127(13), p.e2021JD035658_1 - e2021JD035658_21, 2022/07

 Times Cited Count:0 Percentile:18.28(Meteorology & Atmospheric Sciences)

The abundance of cosmogenic isotopes in natural archives carries important information about the complex pathways from their source in the upper atmosphere to their deposition via atmospheric transport processes. Here, we use a new modelling framework to (a) estimate the $$^{10}$$Be production yield for the 774 CE/775 event, (b) evaluate the performance of our model framework by comparing the model results to four ice core records and (c) investigate the atmospheric pathways with a state-of-the-art climate model in detail. The results give new constraints regarding the seasonal timing of the event, underpin the role of the background conditions in the stratosphere, and highlight regional variations in the cosmogenic surface flux.

Journal Articles

Transport model comparison studies of intermediate-energy heavy-ion collisions

Walter, H.*; Colonna, M.*; Cozma, D.*; Danielewicz, P.*; Ko, C. M.*; Kumar, R.*; Ono, Akira*; Tsang, M. Y. B*; Xu, J.*; Zhang, Y.-X.*; et al.

Progress in Particle and Nuclear Physics, 125, p.103962_1 - 103962_90, 2022/07

 Times Cited Count:32 Percentile:96.94(Physics, Nuclear)

Transport models are the main method to obtain physics information on the nuclear equation of state and in-medium properties of particles from low to relativistic-energy heavy-ion collisions. The Transport Model Evaluation Project (TMEP) has been pursued to test the robustness of transport model predictions to reach consistent conclusions from the same type of physical model. To this end, calculations under controlled conditions of physical input and set-up were performed by the various participating codes. These included both calculations of nuclear matter in a periodic box, which test individual ingredients of a transport code, and calculations of complete collisions of heavy ions. Over the years, five studies were performed within this project. They show, on one hand, that in box calculations the differences between the codes can be well understood and a convergence of the results can be reached. These studies also highlight the systematic differences between the two families of transport codes, known under the names of Boltzmann-Uehling-Uhlenbeck (BUU) and Quantum Molecular Dynamics (QMD) type codes. On the other hand, there still exist substantial differences when these codes are applied to real heavy-ion collisions. The results of transport simulations of heavy-ion collisions will have more significance if codes demonstrate that they can verify benchmark calculations such as the ones studied in these evaluations.

Journal Articles

$$^{rm 206,207,208,nat}$$Pb(p,x)$$^{194}$$Hg and $$^{209}$$Bi(p,x)$$^{194}$$Hg excitation functions in the energy range 0.04 - 2.6 GeV

Titarenko, Yu. E.*; Batyaev, V. F.*; Pavlov, K. V.*; Titarenko, A. Yu.*; Malinovskiy, S. V.*; Rogov, V. I.*; Zhivun, V. M.*; Kulevoy, T. V.*; Chauzova, M. V.*; Khalikov, R. S.*; et al.

Nuclear Instruments and Methods in Physics Research A, 1026, p.166151_1 - 166151_9, 2022/03

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

The paper presents the $$^{194}$$Hg production cross-sections measured by the direct gamma-spectrometry technique in the samples of lead enriched with isotopes 206, 207 and 208, as well as in the samples of natural lead and bismuth, irradiated by protons of 11 energies in the range from 0.04 to 2.6 GeV. The obtained experimental results are compared with the previous measurements, with the TENDL-2019 data-library evaluations and the simulated data by means of the high-energy transport codes MCNP6.1 (CEM03.03), PHITS (INCL4.6/GEM), Geant4 (INCL++/ABLA) and the nuclear reaction code TALYS.

Journal Articles

Environmental effects on layer-dependent dynamics of Dirac fermions in quasicrystalline bilayer graphene

Zhao, Y.*; Suzuki, T.*; Iimori, T.*; Kim, H.-W.*; Ahn, J. R.*; Horio, Masafumi*; Sato, Yusuke*; Fukaya, Yuki; Kanai, T.*; Okazaki, K.*; et al.

Physical Review B, 105(11), p.115304_1 - 115304_8, 2022/03

 Times Cited Count:1 Percentile:18.86(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

LIVE-J1 experiment on debris melting behavior toward understanding late in-vessel accident progression of the Fukushima Daiichi Nuclear Power Station

Madokoro, Hiroshi; Yamashita, Takuya; Sato, Ikken; Gaus-Liu, X.*; Cron, T.*; Fluhrer, B.*; St$"a$ngle, R.*; Wenz, T.*; Vervoortz, M.*; Mizokami, Shinya

Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 16 Pages, 2022/03

Journal Articles

Japanese pediatric and adult atomic bomb survivor dosimetry; Potential improvements using the J45 phantom series and modern Monte Carlo transport

Griffin, K. T.*; Sato, Tatsuhiko; Funamoto, Sachiyo*; Chizhov, K.*; Domal, S.*; Paulbeck, C.*; Bolch, W.*; Cullings, H. M.*; Egbert, S. D.*; Endo, Akira; et al.

Radiation and Environmental Biophysics, 61(1), p.73 - 86, 2022/03

 Times Cited Count:3 Percentile:56.71(Biology)

To evaluate the potential dosimetry improvements that would arise from their use in a Dosimetry System (DS) at RERF, we have evaluated organ doses in the J45 series using the environmental fluence data for twenty generalized survivor scenarios pulled directly from the current DS. The energy- and angle-dependent gamma and neutron fluences were converted to a phase space source term for use in MCNP6, a modern radiation transport code. Overall, the updated phantom series would be expected to provide dose improvements to several important organs, including the active marrow, colon, and stomach wall (up to 20%, 20%, and 15% impact on total dose, respectively). The impacts on dosimetry were especially significant for neutron dose estimates (up to a two-fold difference) and within organs which were unavailable in the previous phantom series, such as the skin, esophagus, and prostate.

Journal Articles

Track-structure modes in Particle and Heavy Ion Transport code System (PHITS); Application to radiobiological research

Matsuya, Yusuke; Kai, Takeshi; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Hirata, Yuho; Yoshii, Yuji*; Parisi, A.*; Liamsuwan, T.*

International Journal of Radiation Biology, 98(2), p.148 - 157, 2022/02

 Times Cited Count:10 Percentile:81.47(Biology)

When investigating radiation-induced biological effects, it is essential to perform detailed track-structure simulations explicitly by considering each atomic interaction in liquid water (which is equivalent to human tissues) at sub-cellular and DNA scales. The Particle and Heavy Ion Transport code System (PHITS) is a Monte Carlo code which can be used for track structure calculations by employing an original electron track-structure mode (etsmode) and the world-famous KURBUC algorithms (PHITS-KURBUC mode) for protons and carbon ions. In this study, the physical features (i.e., range, radial dose and microdosimetry) of these modes have been verified by comparing to the available experimental data and Monte Carlo simulation results reported in literature. In addition, applying the etsmode to radiobiological study, we estimated the yields of single-strand breaks (SSBs), double-strand breaks (DSBs) and complex DSBs, and evaluated the dependencies of DNA damage yields on incident electron energy. As a result, the simulations suggested that DNA damage types are intrinsically related with the spatial patterns of ionization and electronic excitations and that approximately 500 eV electron can cause much complex DSBs. In this paper, we show the development status of the PHITS track-structure modes and its application to radiobiological research, which would be expected to identify the underlying mechanisms of radiation effects based on physics.

Journal Articles

MIRS: an imaging spectrometer for the MMX mission

Barucci, M. A.*; Reess, J.-M.*; Bernardi, P.*; Doressoundiram, A.*; Fornasier, S.*; Le Du, M.*; Iwata, Takahiro*; Nakagawa, Hiromu*; Nakamura, Tomoki*; Andr$'e$, Y.*; et al.

Earth, Planets and Space (Internet), 73(1), p.211_1 - 211_28, 2021/12

 Times Cited Count:8 Percentile:81.82(Geosciences, Multidisciplinary)

The MMX InfraRed Spectrometer (MIRS) is an imaging spectrometer on board of MMX JAXA mission. MIRS is built at LESIA-Paris Observatory in collaboration with four other French laboratories, collaboration and financial support of CNES and close collaboration with JAXA and MELCO. The instrument is designed to fully accomplish MMX's scientific and measurement objectives. MIRS will remotely provide near-infrared spectral maps of Phobos and Deimos containing compositional diagnostic spectral features that will be used to analyze the surface composition and to support the sampling site selection. MIRS will also study Mars atmosphere, in particular to spatial and temporal changes such as clouds, dust and water vapor.

Journal Articles

The High temperature gas-cooled reactor

F$"u$tterer, M. A.*; Strydom, G.*; Sato, Hiroyuki; Li, F.*; Abonneau, E.*; Abram, T.*; Davies, M. W.*; Kim, M. H.*; Edwards, L.*; Muransky, O.*; et al.

Encyclopedia of Nuclear Energy, Vol.1, p.512 - 522, 2021/06

The HTR is a relatively simple Small Modular Reactor design featuring demonstrated robust passive and inherent safety. It responds to the needs of a very large and growing process heat market in most industrialized countries many of which pursue a stringent policy of reducing fossil fuel burn. The manuscript starts from historical developments. This article also highlights the most significant recent achievements of this technology internationally and explains its potential value in a modern energy economy beyond pure electricity generation. The article concludes with an outlook on work towards building demonstration plants, which are required to de-risk private investments and to incentivize deployment.

Journal Articles

Oxygen enhancement ratios of cancer cells after exposure to intensity modulated X-ray fields; DNA damage and cell survival

Matsuya, Yusuke; McMahon, S. J.*; Butterworth, K. T.*; Naijo, Shingo*; Nara, Isshi*; Yachi, Yoshie*; Saga, Ryo*; Ishikawa, Masayori*; Sato, Tatsuhiko; Date, Hiroyuki*; et al.

Physics in Medicine & Biology, 66(7), p.075014_1 - 075014_11, 2021/04

 Times Cited Count:4 Percentile:48.97(Engineering, Biomedical)

Hypoxic cancer cells within solid tumours show radio-resistance, leading to malignant progression in fractionated radiotherapy. When prescribing dose to tumours under heterogeneous oxygen pressure with intensity-modulated radiation fields, intercellular signalling could have an impact on radiosensitivity between in-field and out-of-field cells. However, the impact of hypoxia on radio-sensitivity under modulated radiation intensity remains uncertain. In this study, we investigate the impact of hypoxia on in-field and out-of-field radio-sensitivities using two types of cancer cells. These in vitro measurements indicate that hypoxia apparently impacts out-of-field cells, although the OER values in out-of-field cells were smaller compared to those for in-field and uniformly irradiated cells. These decreased radio-sensitivities of out-of-field cells were shown as a consistent tendency for both DSB and cell death endpoints, suggesting that radiation-induced intercellular communication is of importance in treatment planning with intensity-modulated radiotherapy.

Journal Articles

Verification of KURBUC-based ion track structure mode for proton and carbon ions in the PHITS code

Matsuya, Yusuke; Kai, Takeshi; Sato, Tatsuhiko; Liamsuwan, T.*; Sasaki, Kohei*; Nikjoo, H.*

Physics in Medicine & Biology, 66(6), p.06NT02_1 - 06NT02_11, 2021/03

 Times Cited Count:14 Percentile:91.15(Engineering, Biomedical)

A general-purpose Monte Carlo radiation transport simulation code, Particle and Heavy Ion Transport code System (PHITS), has the ability to handle diverse particle types over a wide range of energy. In PHITS version 3.20, ion track structure mode has been developed based on the algorithms in the KURBUC code, which enables to simulate the atomic interactions by primary ion and secondary particles (named as PHITS-KURBUC mode). In this study, we compared the range, radial dose distributions, and microdosimetric distributions calculated using the PHITS-KURBUC mode to the corresponding data obtained from the original KURBUC and from other studies. These comparative studies confirm the successful inclusion of the KURBUC code in the PHITS code. As results of the synergistic effect between the macroscopic and microscopic radiation transport codes, this implementation enabled the detailed calculation of the microdosimetric and nanodosimetric quantities under complex radiation fields, such as proton beam therapy with the spread-out Bragg peak. This PHITS-KURBUC mode is expected to pave the way for next-generation radiation researches, such as radiation physics, radiological protection, medical physics, and radiation biology.

Journal Articles

Quasifree neutron knockout reaction reveals a small $$s$$-Orbital component in the Borromean nucleus $$^{17}$$B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

AA2020-0819.pdf:1.29MB

 Times Cited Count:31 Percentile:96.65(Physics, Multidisciplinary)

A quasifree ($$p$$,$$pn$$) experiment was performed to study the structure of the Borromean nucleus $$^{17}$$B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for $$1s_{1/2}$$ and $$0d_{5/2}$$ orbitals, and a surprisingly small percentage of 9(2)% was determined for $$1s_{1/2}$$. Our finding of such a small $$1s_{1/2}$$ component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in $$^{17}$$B. The present work gives the smallest $$s$$- or $$p$$-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of $$s$$ or $$p$$ orbitals is not a prerequisite for the occurrence of a neutron halo.

148 (Records 1-20 displayed on this page)