| Minato Futoshi | Last modified date：2024.06.03 |
Associate Professor /
Physics /
Department of Physics /
Faculty of Sciences
Papers
| 1. | Futoshi Minato, Tomoya Naito, Osamu Iwamoto, Nuclear Many-Body Effects on Particle Emission Following Muon Capture on 28Si and 40Ca, Physical Review C, 10.1103/PhysRevC.107.054314, 107, 5, 054314_1-054314_11, 2023.05, [URL], Background: Muon captures on nuclei have provided us with plenty of knowledge of nuclear properties. Recently, this reaction attracts attention in electronics, because charged particle emissions following muon capture on silicon become to trigger non-negligible soft errors in memory devices. Purpose: To date, there is no theoretical framework based on the nuclear structure that describes a muon capture reaction followed by particle emissions comprehensively. The purpose of this work is to develop a new method that considers the nuclear many-body correlation for the accurate understanding of the soft errors in memory devices. Method: We combined the second Tamm-Dancoff approximation that is used to estimate muon capture rates with the two-component exciton model, the model describing particle emission from the pre-equilibrium state. For particle evaporation from the compound state, the Hauser-Feshbach statistical models were applied. We chose 28Si and 40Ca to check the performance of the framework. Result: We paid attention to the muon capture rates, the particle emission spectra, and the multiplicities that have a close interrelation with each other. We found that the nuclear many-body correlations including two-particle two-hole excitations is a key to explaining them simultaneously. Conclusion: The present study showed that the combination of the microscopic approach of muon capture and the two-component exciton model of particle emission is an effective tool to describe particle emission following the muon captures, giving the nuclear structure information additionally. For a finer understanding of particle emission following muon capture and a validation of the present framework, further experimental studies on particle emission spectra are highly expected.. |
| 2. | Osamu Iwamoto, Nobuyuki Iwamoto, Satoshi Kunieda, Futoshi Minato, Shinsuke Nakayama, Yutaka Abe, Kohsuke Tsubakihara, Shin Okumura, Chikako Ishizuka, Tadashi Yoshida, Satoshi Chiba, Naohiko Otuka, Jean-Christophe Sublet, Hiroki Iwamoto, Kazuyoshi Yamamoto, Yasunobu Nagaya, Kenichi Tada, Chikara Konno, Norihiro Matsuda, Kenji Yokoyama, Hiroshi Taninaka, Akito Oizumi, Masahiro Fukushima, Shoichiro Okita, Go Chiba, Satoshi Sato, Masayuki Ohta, Saerom Kwon, Japanese Evaluated Nuclear Data Library version 5: JENDL-5, Journal of Nuclear Science and Technology, 10.1080/00223131.2022.2141903, 2023.02. |
| 3. | 湊 太志, Niu Z.*, Liang H.*, Calculation of $eta$-decay half-lives within a Skyrme-Hartree-Fock-Bogoliubov energy density functional with the proton-neutron quasiparticle random-phase approximation and isoscalar pairing strengths optimized by a Bayesian method, Physical Review C, 10.1103/PhysRevC.106.024306, 106, 2, 024306_1-024306_13, 2022.08. |
| 4. | Yasuki Nagai, Masako Kawabata, Shintaro Hashimoto, Kazuaki Tsukada, Kazuyuki Hashimoto, Shoji Motoishi, Hideya Saeki, Arata Motomura, Futoshi Minato, Masatoshi Itoh, Estimated Isotopic Compositions of Yb in Enriched Yb-176 for Producing Lu-177 with High Radionuclide Purity by Yb-176(d,x) Lu-177, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.91.044201, 91, 4, 2022.04, Recently, great interest has arisen concerning Lu-177 as one of the most important therapeutic radionuclides for treating neuroendocrine tumors. This has driven demand for Lu-177 with high radionuclide purity produced in accelerators, by using highly enriched Yb-176 samples to develop a variety of mix-labelled radiopharmaceuticals. In this paper, a method is presented to estimate isotopic compositions of enriched Yb-176 samples required for achieving large-scale production of Lu-177 having high radionuclide purity by the Yb-176(d,x)Lu-177 reaction. These isotopic compositions were estimated using the latest measured excitation functions of the Yb-nat(d,x)Lu reaction that were confirmed in this study by measuring the integral yields of the reaction, and a particle transport simulation code. The estimated radionuclide purity of Lu-177 for commercially available enriched Yb-176 sample is over 99% at a deuteron energy of 20MeV. The method plays an important role in determining isotopic compositions of enriched samples for producing high purity medical radionuclides in accelerators.. |
| 5. | 岩本 修, 岩本 信之, 柴田 恵一, 市原 晃, 国枝 賢, 湊 太志, 中山 梓介, JENDLの現状, EPJ Web of Conferences, 10.1051/epjconf/202023909002, 239, 09002_1-09002_6, 2020.09. |
| 6. | Maureen Ciccarelli, Futoshi Minato, Tomoya Naito, Theoretical study of Nb isotope productions by muon capture reaction on Mo100, Physical Review C, 10.1103/physrevc.102.034306, 102, 3, 2020.09, Background: The isotope Mo-99, the generator of Tc-99m used for diagnostic imaging, is supplied by extraction from fission fragments of highly enriched uranium in reactors. However, a reactor-free production method of Mo-99 is sought worldwide due to concerns about nuclear proliferation.Purpose: Production methods using accelerators have attracted attention. Recently, Mo-99 production through a muon capture reaction was proposed and it was found that about 50% of Mo-100 turned into Mo-99 through the Mo-100 (mu-, n) reaction [I. Hashim et al., Nucl. Instrum. Methods Phys. Res., Sect. A 963, 163749 (2020)]. However, the detailed physical process of the muon capture reaction is not completely understood. We therefore study the muon capture reaction on Mo-100 by a theoretical approach.Methods: We use the proton-neutron quasiparticle random phase approximation to calculate the muon capture rate. The muon wave function is calculated with consideration of the electronic distribution of the atom and the nuclear charge distribution. The particle evaporation process from the daughter nucleus, Nb-100, is calculated by the Hauser-Feshbach statistical model.Results: From the model calculation, about 38% of Mo-100 is converted to Mo-99 through the muon capture reaction, which is in reasonable agreement with the experimental data. It is revealed that negative parity states, especially the 1(-) state, play an important role in Mo-100 (mu(-), n)Nb-99. Charged particle emission is hindered due to its large separation energy and the Coulomb barrier.Conclusions: Isotope production by the muon capture reaction strongly depends on the nuclear structure. To understand the mechanism, excitation energy functions have to be known microscopically.. |
| 7. | Kazuaki Tsukada, Yasuki Nagai, Shintaro Hashimoto, Futoshi Minato, Masako Kawabata, Yuichi Hatsukawa, Kazuyuki Hashimoto, Satoshi Watanabe, Hideya Saeki, Shoji Motoishi, Anomalous Radioisotope Production for (ZnO)-Zn-68 Using Polyethylene by Accelerator Neutrons, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.89.034201, 89, 3, 2020.03, We measured the yields of radionuclides after neutron irradiation on an enriched (ZnO)-Zn-68 sample covered with polyethylene blocks. The neutrons were generated from the Be-9(d,n) reaction by 40 and 50 MeV deuterons. For 50 MeV deuterons we observed anomalously enhanced yields of Ga-67, Ga-66, Zn-69(m), and Cu-64, more than 20-times larger than the yields for a (ZnO)-Zn-68 sample without the polyethylene blocks. At the same time, the yields of the same radioisotopes produced from an enriched metallic Zn-68 sample were almost insensitive to the presence of polyethylene. On the other hand, for 40 MeV deuterons the enhanced production was not observed. This finding would provide a unique capability of accelerator neutrons to simultaneously produce large amounts of several radioisotopes via neutron-induced reactions on a single sample. The experimental data are compared with the yields calculated by the simulation code Particle and Heavy Ion Transport code System (PHITS). The calculated yields of these radioisotopes produced from the (ZnO)-Zn-68 sample covered with the polyethylene blocks considerably disagree with the measured ones, while for the (ZnO)-Zn-68 sample without the blocks they agree with each other.. |
| 8. | Futoshi Minato, Shin Okumura, Arjan Koning, Toshihiko Kawano, Implementation of the Hauser-Feshbach theory for Fission Product Yield Evaluation and Fission Modelling, DOCUMENTATION SERIES OF THE IAEA NUCLEAR DATA SECTION, IAEA-NDS-230, 2020.02. |
| 9. | Satoshi Kunieda, Naoya Furutachi, Futoshi Minato, Nobuyuki Iwamoto, Osamu Iwamoto, Shinsuke Nakayama, Shuichiro Ebata, Toru Yoshida, Kenji Nishihara, Yukinobu Watanabe, Koji Niita, JENDL/ImPACT-2018: a new nuclear data library for innovative studies on transmutation of long-lived fission products, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, 10.1080/00223131.2019.1647889, 56, 12, 1073-1091, 2019.12, A new nuclear data library, JENDL/ImPACT-2018, was developed for an innovative study on the transmutation of long-lived fission products. Nuclear reaction cross-sections were newly evaluated for incident neutrons and protons up to 200 MeV for 163 nuclides focusing on long-lived nuclei such as Se-79, Zr-93, Pd-107 and Cs-135, adopting some parts of JENDL-4.0. Our challenge was an evaluation of cross-sections for a number of unstable nuclei over a wide energy range where the experimental data were very scarce. We estimated cross-sections based on a nuclear model code CCONE by incorporating an advanced knowledge on the nuclear structure theory and a model-parameterization based on new experimental cross-sections measured by the inverse kinematics. Through comparisons with available experimental data on the stable isotopes, it is found that the present data give better agreements with them than those in the existing libraries. In a neutronics simulation by the PHITS code, we also found that the largest impact of the present library was seen on the estimated amount of isotope productions.. |
| 10. | 古立 直也, 湊 太志, 岩本 修, ランダム生成された共鳴パラメータによる熱中性子捕獲断面積の統計的な性質, Physical Review C, 10.1103/PhysRevC.100.014610, 100, 1, 014610_1-014610_7, 2019.07, 共鳴パラメータの統計的性質を使って求められた熱中性子捕獲断面積$sigma_{ m th}$の統計的不定性について調べた。本研究では、乱数を用いて生成された共鳴パラメータから、$sigma_{ m th}$の確率密度分布を数値的に導出した。この結果、熱中性子エネルギーに最も近い最初の共鳴の統計的ゆらぎによって、熱中性子捕獲断面積が広い範囲に分布することが分かった。また、平均共鳴幅が平均崩壊幅と比較して十分に大きな値を持つ原子核においては、それぞれの$sigma_{ m th}$の確率密度分布が似た形状をしていることも分かった。計算された確率密度分布は、193核種の熱中性子捕獲断面積の実験データと比較され、両者が良い一致を示していることが分かった。. |
| 11. | 古立 直也*, 湊 太志, 岩本 修, 変形および球形状態密度による現象論的準位密度モデル, Journal of Nuclear Science and Technology, 10.1080/00223131.2019.1588801, 56, 5, 412-424, 2019.05, 本研究では、球形状態と変形状態において異なる準位密度パラメータで与えられる現象論的準位密度の計算手法と、$s$波中性子共鳴幅の実験データを用いた準位密度パラメータの最適化法について議論を行う。球形状態から変形状態への遷移の記述は、微視的核構造計算から導出された計算結果をもとに、パラメータ化を実行し、準位密度を導出した。また、得られた準位密度を用いて、統計モデルによる核子・核反応計算も行った。球形,変形およびそれらの中間の状態を持つ原子核を標的核として計算を実行し、得られた結果が実験データとほぼ良い一致を示すことが分かり、本モデルの妥当性が示された。本研究では、計算された断面積に対する回転集団運動による状態密度の増大の効果についても議論を行う。. |
| 12. | Kazuaki Tsukada, Yasuki Nagai, Kazuyuki Hashimoto, Masako Kawabata, Futoshi Minato, Hideya Saeki, Shoji Motoishi, Masatoshi Itoh, Mo-99 Yield Using Large Sample Mass of MoO3 for Sustainable Production of Mo-99, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.87.043201, 87, 4, 2018.04, A neutron source from the C(d,n) reaction has the unique capability of producing medical radioisotopes such as Mo-99 with a minimum level of radioactive waste. Precise data on the neutron flux are crucial to determine the best conditions for obtaining the maximum yield of Mo-99. The measured yield of Mo-99 produced by the 100Mo(n,2n)Mo-99 reaction from a large sample mass of MoO3 agrees well with the numerical result estimated with the latest neutron data, which are a factor of two larger than the other existing data. This result establishes an important finding for the domestic production of Mo-99: approximately 50% of the demand for Mo-99 in Japan could be met using a 100 g (MoO3)-Mo-100 sample mass with a single accelerator of 40 MeV, 2mA deuteron beams.. |
| 13. | Futoshi Minato, Neutron Energy Dependence of Delayed Neutron Yields and its Assessments, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, 10.1080/00223131.2018.1470947, 55, 9, 1054-1064, 2018.03, Incident neutron energy dependence of delayed neutron yields of uranium and plutonium isotopes is investigated. A summation calculation of decay and fission yield data is employed, and the energy dependence of the latter part is considered in a phenomenological way. Our calculation systematically reproduces the energy dependence of delayed neutron yields by introducing an energy dependence of the most probable charge and the odd-even effect. The calculated fission yields are assessed by comparison with JENDL/FPY-2011, delayed neutron activities, and decay heats. Although the fission yields in this work are optimized to delayed neutron yields, the calculated decay heats are in good agreement with the experimental data. Comparison of the fission yields calculated in this work and JENDL/FPY-2011 gave an important insight for the evaluation of the next JENDL nuclear data.. |
| 14. | Futoshi Minato, Yusuke Tanimura, Spin-Isospin Properties of $N=Z$ Odd-Odd Nuclei from a Core+$pn$ Three-Body Model including Core Excitations, EUROPEAN PHYSICAL JOURNAL A, 10.1140/epja/s10050-020-00035-w, 56, 2, 2018.02, For $N=Z$ odd-odd nuclei, a three-body model assuming two valence particles and an inert core can provide an understanding of pairing correlations in the ground state and spin-isospin excitations. However, since residual core-nucleon interactions can have a significant impact on these quantities, the inclusion of core excitations in the model is essential for useful calculation to be performed. The effect of core excitations must be included in order to gain a detailed understanding of both the ground state and spin-isospin properties of these systems. To this end, we include the vibrational excitation of the core nucleus in our model. We solve the three-body core-nucleon-nucleon problem including core vibrational states to obtain the nuclear ground state as well as spin-isospin excitations. The spin-isospin excitations are examined from the point of view of SU(4) multiplets. By including the effect of core excitation, several experimental quantities of $N=Z$ odd-odd nuclei are better described, and the root mean square distances between proton and neutron and that between the center of mass of proton and neutron and core nucleus increase. Large $B$($M1$) and $B$(GT) observed for $^{18}$F and $^{40}$Ca were explained in terms of the SU(4) symmetry. The core nucleus is meaningfully broken by the residual core-nucleon interactions, and various quantities concerning spin-isospin excitations as well as the ground state become consistent with experimental data. Including the core excitation in the three-body model is thus important for a more detailed understanding of nuclear structure.. |
| 15. | Futoshi Minato, Kazuaki Tsukada, Nozomi Sato, Satoshi Watanabe, Hideya Saeki, Masako Kawabata, Shintaro Hashimoto, Yasuki Nagai, Measurement and Estimation of the Mo-99 Production Yield by Mo-100(n,2n)Mo-99, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.86.114803, 86, 11, 2017.11, We, for the first time, measured the yield of Mo-99, the mother nuclide of Tc-99m used in nuclear medicine diagnostic procedures, produced by the Mo-100(n,2n)Mo-99 reaction with accelerator neutrons. The neutrons with a continuous energy spectrum from the thermal energy up to about 40 MeV were provided by the C(d,n) reaction with 40 MeV deuteron beams. It was proved that the Mo-99 yield agrees with that estimated by using the latest data on neutrons from the C(d,n) reaction and the evaluated cross section of the Mo-100(n,2n)Mo-99 reaction given in the Japanese Evaluated Nuclear Data Library. On the basis of the agreement, a systematic calculation was carried out to search for an optimum condition that enables us to produce as much Mo-99 as possible with a good Mo-99/Mo-100 value from an economical point of view. The calculated Mo-99 yield from a 150 g (MoO3)-Mo-100 sample indicated that about 30% of the demand for Mo-99 in Japan can be met with a single accelerator capable of 40 MeV, 2 mA deuteron beams. Here, by referring to an existing F-18-fluorodeoxyglucose (FDG) distribution system we assumed that Tc-99m radiopharmaceuticals formed after separating Tc-99m from Mo-99 can be delivered to hospitals from a radiopharmaceutical company within 6 h. The elution of Tc-99m from Mo-99 twice a day would meet about 50% of the demand for Mo-99.. |
| 16. | T. Shizuma, T. Hayakawa, I. Daito, H. Ohgaki, S. Miyamoto, F. Minato, Low-lying dipole strength in Cr-52, PHYSICAL REVIEW C, 10.1103/PhysRevC.96.044316, 96, 4, 2017.10, The low-lying dipole strength in Cr-52 was measured in nuclear resonance fluorescence experiments using a quasimonochromatic, linearly polarized photon beam. The parities of the excited dipole states were determined by the intensity asymmetry of resonantly scattered gamma rays with respect to the polarization plane of the incident photon beam. We observed 62 resonances at excitation energies between 7.5 and 12.1 MeV. The observed M1 and E1 strengths were compared via random-phase-approximation calculations using the Skyrme interaction. The effects of two-particle-two-hole configuration mixing and tensor force on dipole strength distributions were investigated.. |
| 17. | Osamu Iwamoto, Keiichi Shibata, Nobuygbri Iwamoto, Satoshi Kunieda, Futoshi Minato, Akira Ichihara, Shinsgbre Nakayama, Status of the JENDL project, EPJ Web of Conferences, 10.1051/epjconf/201714602005, 146, 2017.09, Status of the JENDL project after releasing the latest general purpose file JENDL-4.0 is described. By correcting errors and adding covariance data of JENDL-4.0, 38 files have been released as JENDL-4.0u. Development of next general purpose file JENDL-5 is also in progress. New evaluations have been performed for light nuclei, structural materials and fission products. Two special purpose files, JENDL-4.0/HE and JENDL/DDF-2015 were released in 2015. The former includes neutron induced reaction data for 130 nuclides in the energy region up to 200 MeV as well as proton induced reaction data for 133 nuclides. The latter is the decay data file of 3,237 nuclides from Z = 1 to 104 and neutron. Other two special purpose files of activation cross section and photonuclear data are under preparation and will be released soon.. |
| 18. | Tokuro Fukui, Futoshi Minato, Theoretical investigation of two-particle two-hole effect on spin-isospin excitations through charge-exchange reactions, PHYSICAL REVIEW C, 10.1103/PhysRevC.96.054608, 96, 5, 2017.08, Coherent one-particle one-hole (1p1h) excitations have given us effective insights into general nuclear excitations. However, the two-particle two-hole (2p2h) excitation beyond 1p1h is now recognized as critical for the proper description of experimental data of various nuclear responses. The spin-flip charge-exchange reactions $^{48}{ m Ca}(p,n)^{48}{ m Sc}$ are investigated to clarify the role of the 2p2h effect on their cross sections. The Fermi transition of $^{48}{ m Ca}$ via the $(p,n)$ reaction is also investigated in order to demonstrate our framework. The transition density is calculated microscopically with the second Tamm-Dancoff approximation, and the distorted-wave Born approximation is employed to describe the reaction process. A phenomenological one-range Gaussian interaction is used to prepare the form factor. For the Fermi transition, our approach describes the experimental behavior of the cross section better than the Lane model, which is the conventional method. For spin-flip excitations including the GT transition, the 2p2h effect decreases the magnitude of the cross section and does not change the shape of the angular distribution. The $Delta l=2$ transition of the present reaction is found to play a negligible role. The 2p2h effect will not change the angular-distributed cross section of spin-flip responses. This is because the transition density of the Gamow-Teller response, the leading contribution to the cross section, is not significantly varied by the 2p2h effect.. |
| 19. | Futoshi Minato, Tokuro Fukui, Interference Effect Between Neutron Direct and Resonance Capture Reactions For Neutron-Rich Nuclei, FUSION17, 10.1051/epjconf/201716300037, 163, 2017.05, Interference effect of neutron capture cross section between the compound and direct processes is investigated. The compound process is calculated by resonance parameters and the direct process by the potential mode. The interference effect is tested for neutron-rich $^{82}$Ge and $^{134}$Sn nuclei relevant to $r$-process and light nucleus $^{13}$C which is neutron poison in the $s$-process and produces long-lived radioactive nucleus $^{14}$C ($T_{1/2}=5700$ y). The interference effects in those nuclei are significant around resonances, and low energy region if $s$-wave neutron direct capture is possible. Maxwellian averaged cross sections at $kT=30$ and $300$ keV are also calculated, and the interference effect changes the Maxwellian averaged capture cross section largely depending on resonance position.. |
| 20. | Futoshi Minato, Proton-neutron random phase approximation studied by the Lipkin-Meshkov-Glick model in the SU(2) $ imes$ SU(2), XXIII NUCLEAR PHYSICS WORKSHOP MARIE AND PIERRE CURIE: ESSENTIAL PROBLEMS IN NUCLEAR PHYSICS, 2016, 10.5506/APhysPolBSupp.10.131, 10, 1, 131-138, 2016.12, We study the proton-neutron RPA with an extended Lipikin-Meshkov-Glick model. We pay attention to the effect of correlated ground state and the case in which neutron and proton numbers are different. The effect of the correlated ground state are tested on the basis of quasi-boson approximation. We obtain the result that RPA excitation energies and transition strengths are in a good agreement with the exact solution up to a certain strength of the particle-particle interaction. However, the transition strength becomes worse if we consider the case in which neutron and proton numbers are different even at a weak particle-particle interaction.. |
| 21. | Kunieda, Satoshi, Iwamoto, Osamu, Iwamoto, Nobuyuki, Minato, Futoshi, Okamoto, Tsutomu, Sato, Tatsuhiko, Nakashima, Hiroshi, Iwamoto, Yosuke, Iwamoto, Hiroki, Kitatani, Fumito, Fukahori, Tokio, Watanabe, Yukinobu, Shigyo, Nobuhiro, Chiba, Satoshi, Yamano, Naoki, Hagiwara, Masayuki, Niita, Koji, Kosako, Kazuaki, Hirayama, Shusuke, Murata, Toru, Overview of JENDL-4.0/HE and benchmark calculations, JAEA-Conf 2016-004, 10.11484/jaea-conf-2016-004, 41-46, 2016.09. |
| 22. | F. Minato, C. L. Bai, Impact of Tensor Force on beta Decay of Magic and Semimagic Nuclei (vol 110, 122501, 2013), PHYSICAL REVIEW LETTERS, 10.1103/PhysRevLett.116.089902, 116, 8, 2016.02. |
| 23. | M. Martini, S. Goriely, S. Hilaire, S. Péru, F. Minato, Large-scale deformed QRPA calculations of the gamma-ray strength function based on a Gogny force, Journal of Physics: Conference Series, 10.1088/1742-6596/665/1/012058, 665, 1, 2016.01, The dipole excitations of nuclei play an important role in nuclear astrophysics processes in connection with the photoabsorption and the radiative neutron capture that take place in stellar environment. We present here the results of a large-scale axially-symmetric deformed QRPA calculation of the γ-ray strength function based on the finite-range Gogny force. The newly determined γ-ray strength is compared with experimental photoabsorption data for spherical as well as deformed nuclei. Predictions of γ-ray strength functions and Maxwellian-averaged neutron capture rates for Sn isotopes are also discussed.. |
| 24. | O. Iwamoto, N. Iwamoto, S. Kunieda, F. Minato, K. Shibata, The CCONE Code System and its Application to Nuclear Data Evaluation for Fission and Other Reactions, Nuclear Data Sheets, 10.1016/j.nds.2015.12.004, 131, 259-288, 2016.01, A computer code system, CCONE, was developed for nuclear data evaluation within the JENDL project. The CCONE code system integrates various nuclear reaction models needed to describe nucleon, light charged nuclei up to alpha-particle and photon induced reactions. The code is written in the C++ programming language using an object-oriented technology.At first, it was applied to neutron-induced reaction data on actinides, which were compiled into JENDL Actinide File 2008 and JENDL-4.0. It has been extensively used in various nuclear data evaluations for both actinide and non-actinide nuclei. The CCONE code has been upgraded to nuclear data evaluation at higher incident energies for neutron-, proton-, and photon-induced reactions. It was also used for estimating β-delayed neutron emission.This paper describes the CCONE code system indicating the concept and design of coding and inputs. Details of the formulation for modelings of the direct, pre-equilibrium and compound reactions are presented. Applications to the nuclear data evaluations such as neutron-induced reactions on actinides and medium-heavy nuclei, high-energy nucleon-induced reactions, photonuclear reaction and β-delayed neutron emission are mentioned.. |
| 25. | Futoshi Minato, Estimation of 2p2h effect on Gamow-Teller transition with Second Tamm-Dancoff-Approximation, PHYSICAL REVIEW C, 10.1103/PhysRevC.93.044319, 93, 4, 2015.09, Two-particle two-hole (2p2h) effect on the Gamow-Teller (GT) transition for neutron-rich nuclei is studied by the second Tamm-Dancoff approximation (STDA) with the Skyrme interaction. Unstable $^{24}$O and $^{34}$Si, and stable $^{48}$Ca nuclei are chosen to study the quenching and fragmentation of the GT strengths. Correlation of the 2p2h configurations causes $20$% quenching and downward shift of GT giant resonances (GTGRs). The residual interaction changing relative angular momentum, appeared in the tensor force part, gives a meaningful effect to the GT strength distributions. In this work, $17$ to $26$ % of the total GT strengths are brought to high energy region above GTGRs. In particular, the tensor force brings strengths to high energy more than $50$ MeV. STDA calculation within a small model space for 2p2h configuration is also performed and experimental data of $^{48}$Ca is reproduced reasonably.. |
| 26. | 湊 太志, 岩本 修, 自己無撞着QRPA法による中性子過剰核(偶偶核)の$eta$遅延中性子放出の研究, Progress in Nuclear Energy, 10.1016/j.pnucene.2014.07.021, 82, 112-117, 2015.06, 自己無撞着QRPA法を用いて、球形を仮定した中性子過剰核の$eta$崩壊率と$eta$遅延中性子放出率を調べた。娘核(先行核)の高い励起状態からの粒子蒸発の計算には、Hauser-Feshbach統計モデルを用いた。この研究では特に、核構造に関連した2つの効果について議論をする。一つはテンソル力である。これは従来のQRPA法では考慮されていなかった力であり、閉殻構造を持った原子核の$eta$崩壊半減期を再現するために重要なファクターである。もう一つは、アイソスピン$T=0$の有限レンジ力の対相関である。テンソル力も$T=0$の対相関も、先行核の励起状態のエネルギーを下げるという重要な効果を持っている。さらに、それらの効果は、中性子しきい値以上の励起状態へ崩壊する分岐比を減らし、結果として、$eta$遅延中性子数の予測値は、テンソル力と有限レンジ力の対相関を考慮しなかった場合に比べて、小さくなるということがわかった。今回の研究内容は、将来的に核分裂生成物の$eta$遅延中性子量評価データへ応用する。. |
| 27. | Nozomi Sato, Kazuaki Tsukada, Satoshi Watanabe, Noriko S. Ishioka, Masako Kawabata, Hideya Saeki, Yasuki Nagai, Tadahiro Kin, Futoshi Minato, Nobuyuki Iwamoto, Osamu Iwamoto, First Measurement of the Radionuclide Purity of the Therapeutic Isotope Cu-67 Produced by Zn-68(n, x) Reaction Using C-nat(d, n) Neutrons, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.83.073201, 83, 7, 2014.07, We have for the first time studied the radionuclide purity of the therapeutic isotope Cu-67 produced by the Zn-68(n, x)(67)Cu reaction. The neutrons were obtained by the C-nat(d, n) reaction using 40 MeV deuterons. We measured the gamma-ray spectra of the reaction products produced by bombarding an enriched (ZnO)-Zn-68 sample with the neutrons with a high-purity Ge detector. We found that the relative production yields of the impurity radionuclides Cu-64, Zn-65, and Zn-69m to Cu-67 are extremely low. The result indicates that the Zn-68(n, x)Cu-67 reaction is the most promising among those proposed routes until now for producing high-quality Cu-67, and could solve a longstanding problem of establishing an appropriate production method for Cu-67.. |
| 28. | Toshiyuki Shizuma, Takehito Hayakawa, Christopher T. Angell, Ryoichi Hajima, Futoshi Minato, Kenya Suyama, Michio Seya, Micah S. Johnson, Dennis P. McNabb, Statistical uncertainties of nondestructive assay for spent nuclear fuel by using nuclear resonance fluorescence, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 10.1016/j.nima.2013.11.069, 737, 170-175, 2014.02, We estimated statistical uncertainties of a nondestructive assay system using nuclear resonance fluorescence (NRF) for spent nuclear fuel including low concentrations of actinide nuclei with an intense, mono energetic photon beam. Background counts from radioactive materials inside the spent fuel were calculated with the ORIGEN2.2-UPJ burn-up computer code. Coherent scattering contribution associated with Rayleigh, nuclear Thomson, and Delbruck scattering was also considered. The energy of he coherent scattering overlaps with that L of NRF transitions to the ground state. Here, we propose to measure NRF transitions to the first excited state to avoid the coherent scattering contribution. Assuming that L the total NRF cross-sections are in the range of 3-100 eV b at excitation energies of 225, 3.5, and 5 MeV, statistical uncertainties of the NRF measurement were estimated. We concluded that it is possible to assay 1% actinide content in the spent fuel with 2.2-32% statistical precision during 40005 measurement time for the total integrated cross-section of 30 eV b at excitation energies of 3.5-5 MeV by using a photon beam with an intensity of 106 photons/s/eV. We also examined both the experimental and theoretical NRF cross-sections for actinide nuclei. The calculation based On the quasi-particle random phase approximation suggests the existence of strong magnetic dipole resonances at excitation energies ranging from 2 to 6 MeV with the scattering cross-sections of tens eV b around 5 MeV in U-238. (C) 2013 Published by Elsevier B.V.. |
| 29. | F. Minato, K. Hagino, Sum rule approach to a soft dipole mode in Lambda hypernuclei, PHYSICAL REVIEW C, 10.1103/PhysRevC.88.064303, 88, 6, 2013.12, Applying the sum rule approach, we investigate the energy of a soft dipole motion in Lambda hypernuclei, which results from a dipole oscillation of a Lambda hyperon against the core nucleus. To this end, we systematically study single-Lambda hypernuclei, from O-16 Lambda to Pb-208(Lambda), for which the ground-state wave function is obtained in the framework of Hartree-Fock method with several Skyrme-type Lambda N interactions. Our results indicate that the excitation energy of the soft dipole Lambda mode, E-sd Lambda, decreases as the mass number increases. We find that the excitation energy is well parametrized as E-sd Lambda = 26.6A(-1/3) + 11.2A(-2/3) MeV for the SkM* NN interaction and E-sd Lambda = 21.3A(-1/3) + 22.6A(-2/3) MeV for the SIII NN interaction as a function of mass number A.. |
| 30. | K. Hagino, J. M. Yao, F. Minato, Z. P. Li, M. Thi Win, Collective excitations of Λ hypernuclei, Nuclear Physics A, 10.1016/j.nuclphysa.2012.12.077, 914, 151-159, 2013.09, We discuss low-lying collective excitations of Λ hypernuclei using the self-consistent mean-field approaches. We first discuss the deformation properties of Λ hypernuclei in the sd-shell region. Based on the relativistic mean-field (RMF) approach, we show that the oblate deformation for 28Si may disappear when a Λ particle is added to this nucleus. We then discuss the rotational excitations of MgΛ25 using the three-dimensional potential energy surface in the deformation plane obtained with the Skyrme-Hartree-Fock method. The deformation of MgΛ25 is predicted to be slightly reduced due to an addition of a Λ particle. We demonstrate that this leads to a reduction of electromagnetic transition probability, B(E2), in the ground state rotational band. We also present an application of random phase approximation (RPA) to hypernuclei, and show that a new dipole mode, which we call a soft dipole Λ mode, appears in hypernuclei, which can be interpreted as an oscillation of the Λ particle against the core nucleus. © 2012 Elsevier B.V.. |
| 31. | Futoshi Minato, Evaluation of neutron nuclear data of praseodymium-141 and-143, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, 10.1080/00223131.2013.810125, 50, 9, 873-882, 2013.09, For the next version of JENDL general purpose file, neutron nuclear data on Pr-141,Pr-143 are evaluated considering cross sections and spectra provided from experiments in the fast neutron energy region up to 20 MeV. Total and elastic cross sections are derived from optical model. Pre-equilibrium and direct-reaction processes are taken into account in addition to the compound process. The statistical model is applied to calculate the cross sections above the resolved resonance region. For unstable Pr-143 nuclide having less experimental data, we use the same parameters as Pr-141 for mass-dependent and -independent terms in the optical potential. The resolved resonance parameter remains unchanged from JENDL-4.0. The present evaluations give consistent results with experimental data, reflecting newly measured one. The evaluated data are compiled in ENDF-6 format for the next version of JENDL.. |
| 32. | Yasuki Nagai, Kazuyuki Hashimoto, Yuichi Hatsukawa, Hideya Saeki, Shoji Motoishi, Nozomi Sato, Masako Kawabata, Hideo Harada, Tadahiro Kin, Kazuaki Tsukada, Tetsuya K. Sato, Futoshi Minato, Osamu Iwamoto, Nobuyuki Iwamoto, Yohji Seki, Kenji Yokoyama, Takehiko Shiina, Akio Ohta, Nobuhiro Takeuchi, Yukimasa Kawauchi, Norihito Sato, Hisamichi Yamabayashi, Yoshitsugu Adachi, Yuji Kikuchi, Toshinori Mitsumoto, Takashi Igarashi, Generation of Radioisotopes with Accelerator Neutrons by Deuterons, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.82.064201, 82, 6, 2013.06, A new system proposed for the generation of radioisotopes with accelerator neutrons by deuterons (GRAND) is described by mainly discussing the production of Mo-99 used for nuclear medicine diagnosis. A prototype facility of this system consists of a cyclotron to produce intense accelerator neutrons from the natC(d,n) reaction with 40MeV 2mA deuteron beams, and a sublimation system to separate Tc-99m from an irradiated (MoO3)-Mo-100 sample. About 8.1 TBq/week of Mo-99 is produced by repeating irradiation on an enriched Mo-100 sample (251 g) with accelerator neutrons for two days three times. It meets about 10% of the Mo-99 demand in Japan. The characteristic feature of the system lies in its capability to reliably produce a wide variety of high-quality, carrier-free, carrier-added radioisotopes with a minimum level of radioactive waste without using uranium. The system is compact in size, and easy to operate; therefore it could be used worldwide to produce radioisotopes for medical, research, and industrial applications.. |
| 33. | F. Minato, C. L. Bai, Impact of tensor force on β decay of magic and semimagic nuclei, Physical Review Letters, 10.1103/PhysRevLett.110.122501, 110, 12, 122501-1-122501-5, 2013.03, The effect of the tensor force on β decay is studied in the framework of the proton-neutron random phase approximation with the Skyrme force. The investigation is performed for even-even semimagic and magic nuclei, Si34, Ni68,78, and Sn132. The tensor correlation induces strong impact on the low-lying Gamow-Teller state. In particular, it improves the β-decay half-lives. Q and ft values are also investigated and compared with experimental data. © 2013 American Physical Society.. |
| 34. | Tadahiro Kin, Yasuki Nagai, Nobuyuki Iwamoto, Futoshi Minato, Osamu Iwamoto, Yuichi Hatsukawa, Mariko Segawa, Hideo Harada, Chikara Konno, Kentaro Ochiai, Kosuke Takakura, New Production Routes for Medical Isotopes Cu-64 and Cu-67 Using Accelerator Neutrons, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.7566/JPSJ.82.034201, 82, 3, 2013.03, We have measured the activation cross sections producing Cu-64 and Cu-67, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14MeV neutrons. We estimated the production yields of Cu-64 and Cu-67 by fast neutrons from C-nat(d,n) with 40 MeV 5 mA deuterons. We used the present result together with the evaluated cross section of Zn isotopes. The calculated Cu-64 yield is 1.8 TBq (175 g Zn-64) for 12 h of irradiation; the yields of Cu-67 by Zn-67(n,p) Cu-67 and Zn-68(n,x)Cu-67 were 249 GBq (184 g Zn-67) and 287 GBq (186 g Zn-68) at the end of 2 days of irradiation, respectively. From the results, we proposed a new route to produce 67Cu with very little radionuclide impurity via the Zn-68(n,x) Cu-67 reaction, and showed the Zn-64(n,p)Cu-64 reaction to be a promising route to produce Cu-64. Both Cu-67 and Cu-64 are noted to be produced using fast neutrons.. |
| 35. | Masumi Oshima, Tadahiro Kin, Shoji Nakamura, Michio Honma, Futoshi Minato, Takehito Hayakawa, Kaoru Y. Hara, Atsushi Kimura, Mitsuo Koizumi, Hideo Harada, Jun Goto, Yukihiro Murakami, Spectroscopic Study of Ni-63 via Cold Neutron Capture Reaction: I. Nuclear Structure of Ni-63, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.1143/JPSJ.81.084201, 81, 8, 2012.08, The gamma-radiation has been investigated for Ni-63 produced by cold neutron capture in an enriched Ni-62 sample. The 315 gamma-rays produced were placed in a Ni-63 level scheme, in which 272 placements are new. We determined the excitation energies with 0.2-0.8 keV error and the branching ratios of 62 bound levels in Ni-63, including 30 new levels. The Q-value of the Ni-62(n, gamma)Ni-63 reaction amounts to 6837.75 +/- 0.18 keV. A large-scale shell-model calculation was performed that included the four single-particle orbits of 0f(7/2), 1p(3/2), 0f(5/2), and 1p(1/2), assuming an inert Ca-40 core for negative-parity states, and those of 1p(3/2), 0f(5/2), 1p(1/2), and 0g(9/2), assuming a Ni-56 core for positive-parity states. The energies of the low-lying Ni-63 states were successfully reproduced. A mean-field statistical-model calculation was also performed by using a self-consistent interaction between the Hartree-Fock + Bardeen-Cooper-Schrieffer method and the statistical calculation. The calculation result is consistent with the experimental level density of Ni-63.. |
| 36. | F. Minato, K. Hagino, Application of random-phase approximation to vibrational excitations of double-Lambda hypernuclei, PHYSICAL REVIEW C, 10.1103/PhysRevC.85.024316, 85, 2, 2012.02, Using the Hartree-Fock plus random phase approximation (HF + RPA), we study the impurity effect of Lambda hyperon on the collective vibrational excitations of double-Lambda hypernuclei. To this end, we employ Skyrme-type Lambda N and Lambda Lambda interactions for the HF calculations, and the residual interactions for the RPA are derived with the same interactions. We find that the inclusion of two Lambda hyperons in O-16 shifts the collective states toward higher energies. In particular, the energy of the giant monopole resonance of 18 O-18(Lambda Lambda), as well as that of Pb-210(Lambda Lambda), becomes higher. This implies that the effective incompressibility modulus increases owing to the impurity effect of Lambda particles, if the beta-stability condition is not imposed.. |
| 37. | Futoshi Minato, Nuclear Level Densities with Microscopic Statistical Method Using a Consistent Residual Interaction, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, 10.3327/jnst.48.984, 48, 7, 984-992, 2011.07, Nuclear level density (NLD) evaluated under the framework of the microscopic statistical method is examined. We calculate single-particle levels by the Skyrme-Hartree-Fock (SHF) + Bardeen-Cooper-Schrieffer (BCS) method, and the grand partition function is calculated with the same two-body interaction as used in the SHF+BCS method. The results are compared with preceding theoretical calculations using different residual interactions. Cumulative numbers and s-wave neutron resonance spacings are reproduced fairly well. The effect of a renormalization term neglected in conventional microscopic statistical methods is also investigated. In order to test a practical application, we calculate neutron capture cross section and compare it with experimental results.. |
| 38. | F. Minato, S. Chiba, Fission barrier of actinide nuclei with double-Lambda particles within the Skyrme-Hartree-Fock method, NUCLEAR PHYSICS A, 10.1016/j.nuclphysa.2011.02.127, 856, 1, 55-67, 2011.04, Fission barrier of actinide nuclei including two Lambda hyperons is studied in the framework of the Skyrme-Hartree-Fock approach at zero temperature. We adopt the zero-range Skyrme-type interaction between Lambda-N and Lambda-Lambda. Fission barrier is investigated using several parameter sets for Lambda Lambda interactions. We obtain the result that the barrier height becomes higher as the number of Lambda particle increases and the barrier width has a dependence on the Lambda Lambda interaction. A relation between Lambda binding energy and density distribution of Lambda particle inside a core nucleus is also discussed. We found that the both Lambda particles are attracted into heavier fission fragment. (C) 2011 Elsevier B.V. All rights reserved.. |
| 39. | Futoshi Minato, Yasuki Nagai, Estimation of Production Yield of Mo-99 for Medical Use using Neutrons from C-nat(d, n) at E-d=40 MeV, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 10.1143/JPSJ.79.093201, 79, 9, 2010.09, We estimated the production yield of Mo-99 from Mo-100(n, 2n)Mo-99 using neutrons produced by bombarding a natural carbon target, C-nat, with 40 MeV 5 mA deuterons. We used the latest data for the angular and energy distributions of neutrons from C-nat(d, n) and the evaluated cross section of Mo-100(n, 2n)Mo-99 given in the Japanese Evaluated Nuclear Data Library to estimate the Mo-99 yield. The Mo-99 yields were obtained for different distances d between the carbon target and the Mo-100 sample, and for different Mo-100 sample radii and thicknesses. We typically obtained a 7.1 TBq activity of Mo-99 at the end of neutron irradiation for two days for a Mo-100 sample (251 g) placed at d 2 cm. The obtained Mo-99 activities show that a substantial fraction of the current Mo-99 demand in Japan could be met by adopting the proposed production method.. |
| 40. | Futoshi Minato, Chunlin Bai, beta-DECAY HALF-LIVES AROUND Ni-78 AND Sn-132 IN A SELF-CONSISTENT APPROACH, MODERN PHYSICS LETTERS A, 10.1142/S0217732310000903, 25, 21-23, 2012-2013, 2010.07, beta-decay half-lives around Ni-78 and Sn-132 are studied with proton-neutron Quasiparticle Random Phase Approximation on the basis of Skyrme-Hartree-Fock (SHF) method. We take into account tensor force correlation in calculating the ground and excited states and find it improves the half-life of Sn-132. However, the Q value is still underestimated. We also discuss that half-lives do not strongly depend on type of particle-particle interaction in isospin T = 0 channel.. |
| 41. | F. Minato, S. Chiba, K. Hagino, Fission of heavy Lambda hypernuclei with the Skyrme-Hartree-Fock approach, NUCLEAR PHYSICS A, 10.1016/j.nuclphysa.2009.09.063, 831, 3-4, 150-162, 2009.12, Fission-related phenomena of heavy Lambda hypernuclei are discussed with the constraint Skyrme-Hartree-Fock + BCS (SHF + BCS) method, in which a similar Skyrme-type interaction is employed also for the interaction between a Lambda particle and a nucleon. Assuming that the Lambda particle adiabatically follows the fission motion, we discuss the fission barrier height of (239)(Lambda)U. We find that the fission barrier height increases slightly when the Lambda particle occupies the lowest level. In this case, the Lambda particle is always attached to the heavier fission fragment. This indicates that one may produce heavy neutron-rich Lambda hypernuclei through fission, whose weak decay is helpful for the nuclear transmutation of long-lived fission products. We also discuss cases where the Lambda particle occupies a higher single-particle level. (C) 2009 Elsevier B.V. All rights reserved.. |
| 42. | F. Minato, K. Hagino, beta-decay half-lives at finite temperatures for N=82 isotones, PHYSICAL REVIEW C, 10.1103/PhysRevC.80.065808, 80, 6, 2009.12, Using the finite-temperature quasiparticle random phase approximation (FTQRPA) on the basis of the finite-temperature Skyrme-Hartree-Fock + Bardeen-Cooper-Schrieffer (BCS) method, we study beta(-)-decay half-lives for even-even neutron magic nuclei with N=82 in a finite-temperature environment. We find that the beta(-)-decay half-life first decreases as the temperature increases for all the nuclei we study, although the thermal effect is found to be small at temperatures relevant to r-process nucleosynthesis. Our calculations indicate that the half-life begins to increase at high temperatures for open-shell nuclei. We discuss this behavior in connection to the pairing phase transition.. |
| 43. | F. Minato, K. Hagino, Fission barriers in the neutron-proton isospin plane for heavy neutron-rich nuclei, PHYSICAL REVIEW C, 10.1103/PhysRevC.77.044308, 77, 4, 2008.04, We discuss the sensitivity of fission barrier for heavy neutron-rich nuclei to fission paths in the two-dimensional neutron-proton quadrupole plane. To this end, we use the constrained Skyrme-Hartree-Fock + BCS method, and examine the difference of fission barriers obtained with three constraining operators, that is, the neutron, proton, and mass quadrupole operators. We investigate (220)U, (236)U, and (266)U, that is relevant to r-process nucleosynthesis. We find that the fission barrier heights are almost the same among the three constraining operators even for neutron-rich nuclei, indicating that the usual way to calculate fission barriers with the mass quadrupole operator is well justified. We also discuss the difference between proton and neutron deformation parameters along the fission paths.. |
| 44. | F. Minato, K. Hagino, N. Takigawa, A. B. Balantekin, Ph. Chomaz, Effect of electronic environment on neutrino-nucleus reactions at r-process sites, PHYSICAL REVIEW C, 10.1103/PhysRevC.75.045802, 75, 4, 2007.04, We discuss effects of the electron plasma on the charged-current neutrino-nucleus reaction (nu(e),e(-)) in a core-collapse supernova environment. We first discuss the electron screening effect on the final state interaction between the outgoing electron and the daughter nucleus. To this end, we employ a schematic surface peaked transition density and solve the Dirac equation for the outgoing electron with the screened Coulomb potential obtained with the Thomas-Fermi approximation. In addition to the screening effect, we also discuss the Pauli blocking effect due to the environmental electrons on the spectrum of the outgoing electron. We find that both effects hinder the cross section of the charged-current reaction, especially at low incident energies.. |
Unauthorized reprint of the contents of this database is prohibited.