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Kunieda, Satoshi; Furutachi, Naoya*; Minato, Futoshi; Iwamoto, Nobuyuki; Iwamoto, Osamu
NEA/NSC/R(2020)4 (Internet), p.329 - 331, 2022/10
A new nuclear data library, ImPACT/LLFP-2018, is developed for an innovative study on the transmutation of long-lived fission products. In this work, we estimated cross-sections based on a nuclear model code CCONE, reflecting new knowledge on the nuclear structure theory and cross-section measurement. For instance, we used microscopic nuclear model to improve a phenomenological level density model. The pre-equilibrium model parameters are also optimized based on new experimental data of RIKEN/RIBF. Present library stores neutron and proton-induced cross-sections up to 200 MeV for 160 stable/unstable nuclei covering the long-lived fission products such as Se, Zr, Pd and Cs. Through a comparison with available experimental data on the stable isotopes, it is found that the present data gives predictions of cross-sections better than those from JENDL-4.0/HE, TENDL-2017 and the INCL model.
Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*
NEA/NSC/R(2020)4 (Internet), p.345 - 349, 2022/10
Long-lived fission products (LLFPs) generated in nuclear reactors are strongly desired to be converted to stable or short-lived nuclides. Recently, it has been considered to transmute LLFPs by spallation reactions with high energy particles, and some experimental studies revealed that spallation reaction cross-sections induced by deuteron are larger than proton-induced ones. These results suggest the possibility that nuclear transmutation of LLFPs using deuteron beams is more efficient than one using proton beams. On the other hand, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. DEURACS has been originally developed to contribute to the design of deuteron accelerator neutron sources. In the present study, we apply DEURACS to calculation of deuteron-induced spallation reactions on LLFPs. Through comparison with measured data, the applicability of DEURACS will be discussed.
Iwamoto, Yosuke; Hashimoto, Shintaro; Sato, Tatsuhiko; Matsuda, Norihiro; Kunieda, Satoshi; elik, Y.*; Furutachi, Naoya*; Niita, Koji*
Journal of Nuclear Science and Technology, 59(5), p.665 - 675, 2022/05
Times Cited Count:14 Percentile:87.70(Nuclear Science & Technology)A benchmark study of PHITS3.24 has been conducted using neutron-shielding experiments listed in the Shielding Integral Benchmark Archive and Database. Five neutron sources were selected, which are generated from (1) 43- and 68-MeV proton-induced reaction on a thin lithium target, (2) 52-MeV proton-induced reaction on a thick graphite target, (3) 590-MeV proton-induced reaction on a thick lead target, (4) 500-MeV proton-induced reaction on a thick tungsten target, and (5) 800-MeV proton-induced reaction on a thick tantalum target. For all cases, overall agreements in the results are satisfactory when using the JENDL-4.0/HE to simulate neutron- and proton-induced reactions up to 200 MeV. However, discrepancies using PHITS default settings are observed in the results. For an accurate neutron-shielding design for accelerator facilities, using JENDL-4.0/HE in the particle and heavy-ion transport code system calculation is favorable.
Kunieda, Satoshi; Furutachi, Naoya; Minato, Futoshi; Iwamoto, Nobuyuki; Iwamoto, Osamu; Nakayama, Shinsuke; Ebata, Shuichiro*; Yoshida, Toru*; Nishihara, Kenji; Watanabe, Yukinobu*; et al.
Journal of Nuclear Science and Technology, 56(12), p.1073 - 1091, 2019/12
Times Cited Count:10 Percentile:62.42(Nuclear Science & Technology)A new nuclear data library, JENDL/ImPACT-2018, is developed for an innovative study on the transmutation of long-lived fission products. Nuclear reaction cross- sections are newly evaluated for incident neutrons and protons up to 200 MeV for 163 nuclides including long-lived nuclei such as Se, Zr, Pd and Cs. Our challenge is an evaluation of cross-sections for a number of unstable nuclei over a wide energy range where the experimental data are very scarce. We estimated cross- sections based on a nuclear model code CCONE that incorporates an advanced knowledge on the nuclear structure theory and a model-parameterization based on a 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 predictions of cross-sections better than those in the existing libraries.
Furutachi, Naoya; Minato, Futoshi; Iwamoto, Osamu
Physical Review C, 100(1), p.014610_1 - 014610_7, 2019/07
Times Cited Count:1 Percentile:11.93(Physics, Nuclear)We investigated the probability distribution of thermal neutron capture cross sections () deduced stochastically with the resonance parameters randomly sampled from Wigner and Porter-Thomas distributions. We found that the typical probability distribution has an asymmetric shape. While there is a long tail on the large side due to a resonance happening to be close to the thermal energy, the multiresonance contribution considerably reduces the probability on the small side. We also found that the probability distributions have a similar shape if nuclei have an average resonance spacing sufficiently larger than an average radiation width. We compared the typical probability distribution with the distribution of the experimental values of 193 nuclei and found a good agreement between them.
Furutachi, Naoya*; Minato, Futoshi; Iwamoto, Osamu
Journal of Nuclear Science and Technology, 56(5), p.412 - 424, 2019/05
Times Cited Count:4 Percentile:28.63(Nuclear Science & Technology)A phenomenological level density model that has different level density parameter sets for the state densities of the spherical and the deformed states, and the optimization of the parameters using the experimental data of the average s-wave neutron resonance spacing are presented. The transition to the spherical state from the deformed one is described using the parameters derived from a microscopic nuclear structure calculation. The nuclear reaction calculation has been performed by the statistical model using the present level density. Resulting cross sections for various reactions with the spherical, deformed and transitional target nuclei shows a fair agreement with the experimental data, which indicates the effectiveness of the present model. The role of the rotational collective enhancement in the calculations of those cross sections is also discussed.
Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*
Physical Review C, 98(4), p.044606_1 - 044606_8, 2018/10
Times Cited Count:14 Percentile:73.71(Physics, Nuclear)Use of deuteron-induced spallation reactions at intermediate energies has recently been proposed for transmutation of several long-lived fission products (LLFPs). In the design study of a transmutation system using a deuteron primary beam, accurate cross section data of deuteron-induced reactions on the LLFPs are indispensable. In the present study, production cross sections of residual nuclei in the deuteron-induced reactions on Zr and Pd at MeV/nucleon are analyzed using DEURACS, in which the breakup processes are explicitly taken into account. The calculated values reproduced the experimental data quantitatively well. From a component-by-component analysis, it was found that the components of nucleon absorption make the significant contributions to residual nuclei production. This result strongly indicates that consideration of the breakup processes is essentially important to predict production of residual nuclei in deuteron-induced reactions.
Minato, Futoshi; Iwamoto, Osamu; Minomo, Kosho*; Ogata, Kazuyuki*; Iwamoto, Nobuyuki; Kunieda, Satoshi; Furutachi, Naoya
EPJ Web of Conferences, 146, p.12032_1 - 12032_4, 2017/09
Times Cited Count:1 Percentile:59.51(Nuclear Science & Technology)Phenomenological optical potential is known to be able to describe the elastic scattering process. It is applied widely to the nuclear data evaluation of the cross section. Many kinds of the optical potential have been studied so far. However, the parameters in the phenomenological optical potentials are determined so as to reproduce existing experimental data, so that use of it for unmeasured nuclei such as neutron-rich nuclei is not necessarily reliable. Recently, a new optical potential derived from the microscopic effective reaction theory (MERT) was proposed. Since the formulation of MERT is based on the NN effective interaction, any parameterizations in the optical potential aren't needed. Therefore, it is capable of calculating nuclei whose scattering cross section isn't measured. We incorporate the optical potentials of MERT in code CCONE and start nuclear data evaluation of several nuclei. In this work, we discuss difference of cross sections evaluated by MERT's optical potentials and conventional phenomenological ones.
Furutachi, Naoya; Minato, Futoshi; Iwamoto, Osamu
JAEA-Conf 2016-004, p.93 - 98, 2016/09
To investigate feasibility of the nuclear transmutation of long-lived fission products (LLFPs), nuclear data used in the simulation calculation of transmutation system is essential. To improve the precision of simulation calculation, the nuclear data of various nuclei produced via nuclear transmutation of LLFPs involved in the simulation is also important. Since wide range of nuclei are expected to be produced depends on the method of transmutation, and there are no available experimental data for some of them, a systematic information based on a microscopic calculation is desirable. In this work, we have performed microscopic nuclear structure calculation to derive the structure parameters used in the nuclear data evaluation. We have calculated deformation parameters and ground-state spin and parities for Z = 30-55 medium nuclei including odd-even and odd-odd nuclei, expected to be produced via the transmutation of Se, Zr, Pd and Cs, using Hartree-Fock-Bogoliubov (HFB) theory. The calculation was done by HFBTHO code. The results are compared with the available experimental data, and reliability of the prediction with the present method is discussed.
Iwamoto, Naoya*; Azarov, A.*; Oshima, Takeshi; Moe, A. M. M.*; Svensson, B. G.*
Materials Science Forum, 858, p.357 - 360, 2016/05
Iwamoto, Naoya*; Azarov, A.*; Oshima, Takeshi; Moe, A. M. M.*; Svensson, B. G.*
Journal of Applied Physics, 118(4), p.045705_1 - 045705_8, 2015/07
Times Cited Count:6 Percentile:26.00(Physics, Applied)Lohrmann, A.*; Iwamoto, Naoya*; Bodrog, Z.*; Castelletto, S.*; Oshima, Takeshi; Karle, T. J.*; Gali, A.*; Prawer, S.*; McCallum, J. C.*; Johnson, B. C.*
Nature Communications (Internet), 6, p.7783_1 - 7783_7, 2015/07
Times Cited Count:157 Percentile:97.03(Multidisciplinary Sciences)Pastuovi, *; Capan, I.*; Cohen, D.*; Forneris, J.*; Iwamoto, Naoya*; Oshima, Takeshi; Siegele, R.*; Hoshino, Norihiro*; Tsuchida, Hidekazu*
Nuclear Instruments and Methods in Physics Research B, 348, p.233 - 239, 2015/04
Times Cited Count:7 Percentile:49.28(Instruments & Instrumentation)Kada, Wataru*; Kambayashi, Yuya*; Iwamoto, Naoya*; Onoda, Shinobu; Makino, Takahiro; Koka, Masashi; Kamiya, Tomihiro; Hoshino, Norihiro*; Tsuchida, Hidekazu*; Kojima, Kazutoshi*; et al.
Nuclear Instruments and Methods in Physics Research B, 348, p.240 - 245, 2015/04
Times Cited Count:4 Percentile:31.62(Instruments & Instrumentation)Kada, Wataru*; Iwamoto, Naoya; Sato, Takahiro; Onoda, Shinobu; Grilj, V.*; Skukan, N.*; Koka, Masashi; Oshima, Takeshi; Jaki, M.*; Kamiya, Tomihiro
Nuclear Instruments and Methods in Physics Research B, 331, p.113 - 116, 2014/07
Times Cited Count:24 Percentile:86.20(Instruments & Instrumentation)no abstracts in English
Fujita, Natsuko; Iwamoto, Naoya; Onoda, Shinobu; Makino, Takahiro; Oshima, Takeshi
Materials Science Forum, 778-780, p.1042 - 1045, 2014/02
Times Cited Count:1 Percentile:52.34(Crystallography)A Silicon Carbide (SiC) dosimeter has been exposed to -rays emitted from a Co source in order to test the response of radiation-induced current in the dose rate ranging from 0.4 Gy/h to 4 kGy/h. The SiC dosimeter in this study is a high purity semi-insulating 4H-SiC with nickel and aluminum electrode. The radiation-induced currents in the dosimeter show a linear relationship with the dose rate, and are repeatable and stable.
Iwamoto, Naoya; Onoda, Shinobu; Fujita, Natsuko; Makino, Takahiro; Oshima, Takeshi
Materials Science Forum, 778-780, p.289 - 292, 2014/02
Times Cited Count:0 Percentile:0.00(Crystallography)Makino, Takahiro; Deki, Manato; Iwamoto, Naoya; Onoda, Shinobu; Hoshino, Norihiro*; Tsuchida, Hidekazu*; Hirao, Toshio*; Oshima, Takeshi
IEEE Transactions on Nuclear Science, 60(4), p.2647 - 2650, 2013/08
Times Cited Count:18 Percentile:78.45(Engineering, Electrical & Electronic)Heavy ion induced anomalous charge collection was observed from 4H-SiC Schottky barrier diodes. It is suggested that the incident ion range with suspect to the thickness of the epi-layer of the SBD in key to understanding these observation and the understanding mechanism.
Kada, Wataru; Kamiya, Tomihiro; Iwamoto, Naoya; Onoda, Shinobu; Grilj, V.*; Skukan, N.*; Makino, Takahiro; Koka, Masashi; Sato, Takahiro; Jaki, M.*; et al.
Transactions of the Materials Research Society of Japan, 38(2), p.279 - 282, 2013/07
Diamond is interested by many researchers as an excellent candidate material with advantages in the radiation-hardness. For the time-resolved detection of single-ions with several hundred MeV, transmission E detector using thin film CVD diamond is now under investigation for the futuristic utilization in a microbeam line of the AVF cyclotron at JAEA/Takasaki TIARA facility as replacing materials of the beam extraction window. In this research, a Single Crystalline (SC) 50 m thick CVD diamond film ion detector was fabricated for the investigation of the responses and radiation hardness under the focused ion microbeam irradiation. Transient Ion Beam Induced Current (TIBIC) experiment was executed by single hit irradiation of 15 MeV O scanning area of 50 m and the transient signals with time width of several nano-secounds were consecutively recorded by a high speed (15 GHz) Digital Storage Oscilloscope during the irradiation. The decreases in the individual pulse height was observed by increasing the total amount of the ion dose irradiated in the focused area. These changes were recovered in temporal conversion of applied bias voltages thus trend of decrease were able to be controlled by changing bias settings and irradiation conditions during the experiments.
Iwamoto, Naoya; Onoda, Shinobu; Makino, Takahiro; Oshima, Takeshi; Kojima, Kazutoshi*; Nozaki, Shinji*
Proceedings of SPIE, Vol.8725 (CD-ROM), 8 Pages, 2013/06
Times Cited Count:0 Percentile:0.00(Nanoscience & Nanotechnology)