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Abreu, L. M.*; Gubler, P.; Khemchandani, K. P.*; Martnez Torres, A.*; Hosaka, Atsushi
Physics Letters B, 860, p.139175_1 - 139175_7, 2025/01
Times Cited Count:0Parisi, A.*; Furutani, K. M.*; Sato, Tatsuhiko; Beltran, C. J.*
Medical Physics, 51(10), p.7589 - 7605, 2024/10
Times Cited Count:0 Percentile:0.00(Radiology, Nuclear Medicine & Medical Imaging)In this study, we have developed an approximate MKM (microdosimetric kinetic model) based on LET (dose-averaged linear energy transfer) to address the challenges of biological relative effectiveness (RBE) models for proton therapy. This is an attempt to apply the mechanism-based approach used in carbon ion therapy to proton beams. This LET-based MKM establishes a correlation between dose-averaged LET and microbiological indices and successfully models survival rates for multiple cell lines. This has resulted in a mathematical description of RBE based on physical quantities that can be readily used in proton therapy planning systems.
Parisi, A.*; Furutani, K. M.*; Sato, Tatsuhiko; Beltran, C. J.*
Quantum Beam Science (Internet), 8(3), p.18_1 - 18_16, 2024/09
Endo, Shunsuke; Abe, Ryota*; Fujioka, Hiroyuki*; Ino, Takashi*; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kawamura, Shiori*; Kimura, Atsushi; Kitaguchi, Masaaki*; Kobayashi, Ryuju*; et al.
European Physical Journal A, 60(8), p.166_1 - 166_10, 2024/08
Times Cited Count:0 Percentile:0.00(Physics, Nuclear)Smallcombe, J.; Garnsworthy, A. B.*; Korten, W.*; Singh, P.*; Muir, D.*; Prchniak, L.*; Ali, F. A.*; Andreoiu, C.*; Ansari, S.*; Ball, G. C.*; et al.
Physical Review C, 110(2), p.024318_1 - 024318_16, 2024/08
Times Cited Count:0 Percentile:0.00(Physics, Nuclear)Ahmed, Z.*; Wu, S.*; Pellegrini, M.*; Okamoto, Koji*; Sharma, A.*; Yamano, Hidemasa
Proceedings of 14th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation, and Safety (NTHOS-14) (Internet), 14 Pages, 2024/08
The analysis show that once eutectic reaction occurs, the boron diffuses into the stainless steel (SS) wall. Melting initiates at the BC and SS interface, with melt flow following SS cladding penetration. Also, we observed that as temperature rises, a proportional increase in the boron concentration within the melt. The updated MPS method indicated a computational capability of the eutectic reaction model used to effectively analyze control rod eutectic reactions, simulating severe accidents, and its subsequent relocation to understand the effect of B
C ingress into the core.
Yamano, Hidemasa; Takai, Toshihide; Emura, Yuki; Fukuyama, Hiroyuki*; Higashi, Hideo*; Nishi, Tsuyoshi*; Morita, Koji*; Nakamura, Kinya*; Ahmed, Z.*; Pellegrini, M.*
Proceedings of 14th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation, and Safety (NTHOS-14) (Internet), 12 Pages, 2024/08
This paper describes the project overview and progress of experimental and analytical studies conducted until 2022. A specific result in this paper is to obtain first experimental data of BC-SS eutectic freezing.
Costantini, J.-M.*; Ogawa, Tatsuhiko
Quantum Beam Science (Internet), 8(3), p.20_1 - 20_16, 2024/08
A novel Coulomb spike concept is applied to the radiation damage induced in LiF and SiO with about the same mass density (
2.65 g cm
) by
Ni and
Kr ions of 1.0-MeV/u energy for about the same electronic energy loss (10 MeV/um). The distribution of ionizations and electrostatic energy gained in the electric field by the ionized atoms is computed with the PHITS code for both targets. Further, the atomic collision cascades induced by these low energy hot ions of about 500 eV are simulated with the SRIM2013 code. It is found that melting is reached in a small volume for SiO
due to the energy deposition in the subthreshold events of nuclear collisions induced by the Si and O ions. For LiF, the phonon contribution to the stopping power of the lighter Li and F ions is not sufficient to induce melting, even though the melting temperature is lower than for SiO
. The formation of amorphous domains in SiO
is likely after fast quenching of the small molten pockets, whereas only point defects may be formed in LiF.
Hong, Z.*; Ahmed, Z.*; Pellegrini, M.*; Yamano, Hidemasa; Erkan, N.*; Sharma, A. K.*; Okamoto, Koji*
Progress in Nuclear Energy, 171, p.105160_1 - 105160_13, 2024/06
Times Cited Count:3 Percentile:95.99(Nuclear Science & Technology)In this study, it is found that the eutectic reaction between BC powder and stainless steel (SS) is considerably more rapid than that between the B
C pellet and SS. The derived reaction rate constant values for powder and pellet cases are consistently based on the reference values. Also, a composition analysis using SEM/EDS was conducted for the detailed microstructures of the powder and pellet samples. In the powder case, only one thick layer is found as the reaction layer consisting of (Fe, Cr)B precipitate, including B
C powder. In the pellet case, two layers are found in the reaction layer.
Ahmed, Z.*; Sharma, A. K.*; Pellegrini, M.*; Yamano, Hidemasa; Kano, Sho*; Okamoto, Koji*
Ceramics International, 50(10), p.17665 - 17680, 2024/05
Times Cited Count:2 Percentile:77.98(Materials Science, Ceramics)In this study, we identified two distinct failure mechanisms: the separation of stainless steel from the BC pellet, resulting in the formation of a later melting drop, and the fracture of the B
C pellet into multiple pieces, possibly due to thermal stress. The visualization technique and thermal interfacial resistance analysis precisely captured the eutectic temperature.
Baccou, J.*; Glantz, T.*; Ghione, A.*; Sargentini, L.*; Fillion, P.*; Damblin, G.*; Sueur, R.*; Iooss, B.*; Fang, J.*; Liu, J.*; et al.
Nuclear Engineering and Design, 421, p.113035_1 - 113035_16, 2024/05
Times Cited Count:4 Percentile:95.99(Nuclear Science & Technology)Honda, Maki; Martschini, M.*; Marchhart, O.*; Steier, P.*; Golser, R.*; Sakaguchi, Aya*
Hoshasen (Internet), 48(4), p.130 - 136, 2024/02
Strontium-90 (Sr, 28.9 years) is a key fission product nuclide in internal dose assessment because it accumulates in bones and teeth in the body, causing health problems. Therefore, it is essential to know the distribution of
Sr in the environment and its temporal variation (
Sr enrichment in biota), which requires efficient analysis of many environmental samples. An analysis of environmental samples with known
Sr concentrations conducted with the 3 MV AMS facility (VERA: Vienna Environmental Research Accelerator) at the University of Vienna, Austria, towards the practical application of
Sr AMS, the results of which are detailed in this paper. In this study, the validity of the AMS method was demonstrated by analyzing environmental samples with known
Sr concentrations (IAEA-447, IAEA-A-12, and IAEA-TEL-2015-03 sample 5: 1 dry-g each). The chemical separation developed in this study takes approximately two days and is a more straightforward procedure than conventional
-ray detection methods. The
Sr measurements were conducted on the AMS system combined with the Ion Laser InterAction Mass Spectrometry (ILIAMS) system. The AMS method achieved a limit of detection
0.1 mBq (
1.3
10
atoms) for
Sr, which is 1/30th of typical
-ray detection. As a result of the lower detection limit, the AMS method allows
Sr quantification with smaller sample volumes. For example, a Japanese freshwater sample with a
Sr concentration of 4 mBq/L requires a sample volume of 5 liter
Watabe, Hiroshi*; Sato, Tatsuhiko; Yu, K. N.*; Zivkovic, M.*; Krstic, D.*; Nikezic, D.*; Kim, K. M.*; Yamaya, Taiga*; Kawachi, Naoki*; Tanaka, Hiroki*; et al.
Radiation Protection Dosimetry, 200(2), p.130 - 142, 2024/02
Times Cited Count:1 Percentile:34.39(Environmental Sciences)Previously, we have developed DynamicMC for modelling relative movement of ORNL phantom in a radiation field for MCNP. Using this software, 3-dimensional dose distributions in a phantom irradiated by a certain mono-energetic source can be deduced through its graphical user interface (GUI). In this study, we extended DynamicMC to be used in combination with the PHITS by providing it with a higher flexibility for dynamic movement for a less sophisticated anthropomorphic phantom. We anticipate that the present work and the developed open-source tools will be in the interest of nuclear radiation physics community for research and teaching purposes.
Koshida, Hiroyuki*; Wilde, M.*; Fukutani, Katsuyuki
Journal of Chemical Physics, 160(3), p.034703_1 - 034703_9, 2024/01
Times Cited Count:0 Percentile:0.00(Chemistry, Physical)Ahmed, Z.*; Sharma, A. K.*; Pellegrini, M.*; Yamano, Hidemasa; Okamoto, Koji*
Proceedings of Saudi International Conference On Nuclear Power Engineering (SCOPE2023) (Internet), 8 Pages, 2023/11
In this study, the eutectic behavior and subsequent melt structure of boron migration are observed by a quantitative and high-resolution visualization method using radiative heating. Experiments were conducted using B4C pellet and powder within SS tubes, replicating the actual control rod design in the temperature range of 1150C to 1372
C to study long-duration melting and relocation behavior. The visualization technique accurately identified the time of eutectic melting onset and the related temperature, pointing out different values for the pellet and the powder cases.
Tamii, Atsushi*; Pellegri, L.*; Sderstr
m, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.
European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09
Times Cited Count:3 Percentile:69.58(Physics, Nuclear)no abstracts in English
Yamano, Hidemasa; Takai, Toshihide; Emura, Yuki; Fukuyama, Hiroyuki*; Nishi, Tsuyoshi*; Morita, Koji*; Nakamura, Kinya*; Pellegrini, M.*
Nihon Kikai Gakkai 2023-Nendo Nenji Taikai Koen Rombunshu (Internet), 5 Pages, 2023/09
A research project has been conducting thermophysical property measurement of a eutectic melt, eutectic melting reaction and relocation experiments, eutectic reaction mechanism investigation, and physical model development on the eutectic melting reaction for reactor application analysis in order to simulate the eutectic melting reaction and relocation behavior of boron carbide as a control rod material and stainless steel during a core disruptive accident in an advanced sodium-cooled fast reactor designed in Japan. This paper describes the project overview and progress until JFY2022.
Maruyama, Yu; Sugiyama, Tomoyuki*; Shimada, Asako; Lind, T.*; Bentaib, A.*; Sogalla, M.*; Pellegrini, M.*; Albright, L.*; Clayton, D.*
Proceedings of 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20) (Internet), p.4782 - 4795, 2023/08
Li, C.-Y.; Wang, K.*; Uchibori, Akihiro; Okano, Yasushi; Pellegrini, M.*; Erkan, N.*; Takata, Takashi*; Okamoto, Koji*
Applied Sciences (Internet), 13(13), p.7705_1 - 7705_29, 2023/07
Times Cited Count:2 Percentile:27.59(Chemistry, Multidisciplinary)Yamashita, Takuya; Honda, Takeshi*; Mizokami, Masato*; Nozaki, Kenichiro*; Suzuki, Hiroyuki*; Pellegrini, M.*; Sakai, Takeshi*; Sato, Ikken; Mizokami, Shinya*
Nuclear Technology, 209(6), p.902 - 927, 2023/06
Times Cited Count:5 Percentile:87.90(Nuclear Science & Technology)