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Journal Articles

Impulsing paradigm change through disruptive technologies program, ImPACT; Reduction and resource recycling of high-level radioactive waste through nuclear transmutation

Iwamoto, Osamu; Fujita, Reiko*; Niita, Koji*; Watanabe, Yukinobu*

Kaku Deta Nyusu (Internet), (122), p.33 - 43, 2019/02

A program related to the transmutation of long-lived fission products (LLFPs) entitled "Reduction and Resource Recycling of High-level Radioactive Wastes through Nuclear Transmutation" has been conducted under the Impulsing Paradigm Change through Disruptive Technologies Program (ImPACT) organized by the Cabinet Office since 2014 and it will be finished in FY 2018. Various activities from acquisition of basic data to examination of transmutation scenario are being carried out as the five separated projects. R&Ds related to nuclear data are also conducted and many outcomes are being produced. This article describes results of the two projects related nuclear data with a short introduction of the whole project.

Journal Articles

Cluster formation in relativistic nucleus-nucleus collisions

Ogawa, Tatsuhiko; Sato, Tatsuhiko; Hashimoto, Shintaro; Niita, Koji*

Physical Review C, 98(2), p.024611_1 - 024611_15, 2018/08

 Percentile:100(Physics, Nuclear)

Particle production by nucleus-nucleus reactions in the energy range from GeV to TeV is substantially important for safety evaluation in heavy ion accelerators and evaluation of space radiation dose. A lot of models and theories have been studied. In the models developed in the past, interaction between nucleons were dependent on the reference frame; therefore the moving incident nucleus and the target nucleus at rest transferred to the common frame were disintegrated. Previously, intentional bias was introduced to the calculation algorithms to supplement stability but residual nucleus mass and secondary particle production was underestimated. In this study, a reaction model JAMQMD was developed, in which intra-nucleon interaction was described in a frame-independent way. This model can reproduce the stability of nuclei regardless of the reference frame and the yield of residual nuclei as well as secondary particles including deuterons. JQMD Ver.2 developed 3 years ago can simulate nucleus-nucleus reactions up to 3 GeV/nucleon; therefore the development of JAMQMD is the doorway to simulate nucleus-nucleus reactions regardless of the incident energy. JAMQMD is an useful model for not only radiation protection studies but also analysis of fundamental physics studies.

Journal Articles

Comparison of cosmic-ray environments on earth, moon, mars and in spacecraft using PHITS

Sato, Tatsuhiko; Nagamatsu, Aiko*; Ueno, Haruka*; Kataoka, Ryuho*; Miyake, Shoko*; Takeda, Kazuo*; Niita, Koji*

Radiation Protection Dosimetry, 180(1-4), p.146 - 149, 2018/08

 Times Cited Count:1 Percentile:38.14(Environmental Sciences)

Cosmic-ray dose rates spatially and temporally change very much. In this study, we compared the calculated cosmic-ray environments on the Earth, Moon, and Mars as well as inside spacecraft on low-earth orbit (LEO) and at interplanetary space. In the calculation, a galactic cosmic-ray model developed in DLR and trapped proton/electron models AP9/AE9 were used for determining the incident cosmic-ray fluxes, and the Particle and Heavy Ion Transport code System, PHITS, was employed for the cosmic-ray transport simulation in the Earth, Lunar, and Martian systems as well as spacecraft. The virtual International Space Station (ISS) model developed by JAXA was adopted as the representative of spacecraft in the PHITS simulation. This paper focuses on the comprehensive discussions on the difference of cosmic-ray environments and the effective methods of their shielding in various exposure situations.

Journal Articles

Radiation damage calculation in PHITS and benchmarking experiment for cryogenic-sample high-energy proton irradiation

Iwamoto, Yosuke; Matsuda, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Nakamoto, Tatsushi*; Yoshida, Makoto*; Ishi, Yoshihiro*; Kuriyama, Yasutoshi*; Uesugi, Tomonori*; Yashima, Hiroshi*; et al.

Proceedings of 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2018) (Internet), p.116 - 121, 2018/07

The radiation damage model in the radiation transport code PHITS has been developed to calculate the basic data of the radiation damage including the energy of the target Primary Knock on Atom (PKA). For the high-energy proton incident reactions, a target PKA created by the secondary particles was more dominant than a target PKA created by the projectile. To validate the radiation damage model in metals irradiated by $$>$$100 MeV protons, we developed a proton irradiation device with a Gifford-McMahon cryocooler to cryogenically cool wire samples. By using this device, the defect-induced electrical resistivity changes related to the DPA cross section of copper and aluminum were measured under irradiation with 125 and 200 MeV protons at cryogenic temperature. A comparison of the experimental data with the calculated results indicates that the DPA cross section with defect production efficiencies provide better quantitative descriptions.

Journal Articles

Features of particle and heavy ion transport code system (PHITS) version 3.02

Sato, Tatsuhiko; Iwamoto, Yosuke; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Tsai, P.-E.; Matsuda, Norihiro; Iwase, Hiroshi*; et al.

Journal of Nuclear Science and Technology, 55(6), p.684 - 690, 2018/06

 Times Cited Count:40 Percentile:0.03(Nuclear Science & Technology)

We have upgraded many features of the Particle and Heavy Ion Transport code System (PHITS) and released the new version as PHITS3.02. The accuracy and the applicable energy ranges of the code were greatly improved and extended, respectively, owing to the revisions to the nuclear reaction models and the incorporation of new atomic interaction models. In addition, several user-supportive functions were developed, such as new tallies to efficiently obtain statistically better results, radioisotope source-generation function, and software tools useful for applying PHITS to medical physics. In this paper, we summarize the basic features of PHITS3.02, especially those of the physics models and the functions implemented after the release of PHITS2.52 in 2013.

Journal Articles

2018 Annual Meeting of Japan Atomic Energy Society, Joint Session of Nuclear Data Subcommittee and Sigma Special Advisory Committee; Present status and future of nuclear data evaluation code in Japan, 4; Role and improvement of nuclear reaction models in the PHITS code

Hashimoto, Shintaro; Sato, Tatsuhiko; Iwamoto, Yosuke; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Niita, Koji*

Kaku Deta Nyusu (Internet), (120), p.26 - 34, 2018/06

Particle and heavy-ion transport code system PHITS has been used for calculations of radiation shielding in accelerator facilities. PHITS describes physical phenomena induced by radiation as combination of transport and collision processes. The collision process including nuclear reactions is simulated by the three-step calculation: a generation of a reaction, pre-equilibrium, and compound processes. In the simulation, many physics models are used. This report explains roles of the models in PHITS and shows their developments we recently performed.

Journal Articles

Integrated simulation of fragmentation, evaporation, and gamma-decay processes in the interaction of cosmic-ray heavy ions with the atmosphere using PHITS

Ogawa, Tatsuhiko; Hashimoto, Shintaro; Sato, Tatsuhiko; Niita, Koji*; Kamae, Tsuneyoshi*

Proceedings of 3rd International Conference on Particle Physics and Astrophysics (ICPPA 2017) (Internet), p.391 - 398, 2018/04

In the reactions of cosmic-ray heavy ions producing high-energy gamma-rays, heavy ions are directed to the ground therefore prompt gamma-rays from projectile fragments are boosted by Doppler effect and observed on the ground. Recently, a lot of experiments pay attention to such high energy gamma-rays. In order to simulate such high-energy gammas, event-by-event simulation of fragmentation reaction which determines the excitation energy and angular momentum of the produced fragment, and de-excitation simulation based on the nuclear structure data. Such models are available in the general-purpose radiation transport simulation code PHITS. JAERI Quantum Molecular Dynamics model was recently updated to accurately simulate charge and mass distribution of fragments. EBITEM, which was released recently, can simulate gamma deexcitation after evaporation based on the excitation energy and angular momentum. Thus latest PHITS can accurately simulate production of $$gamma$$-rays attributed to cosmic-ray heavy ions. This study shows a new approach to reproduce $$gamma$$-rays by cosmic-ray heavy ions.

Journal Articles

Continuous energy adjoint transport for photons in PHITS

Malins, A.; Machida, Masahiko; Niita, Koji*

EPJ Web of Conferences (Internet), 153, p.06001_1 - 06001_9, 2017/09

BB2015-2674.pdf:0.21MB

 Percentile:100

Journal Articles

Recent improvements of particle and heavy ion transport code system: PHITS

Sato, Tatsuhiko; Niita, Koji*; Iwamoto, Yosuke; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Matsuda, Norihiro; Okumura, Keisuke; et al.

EPJ Web of Conferences (Internet), 153, p.06008_1 - 06008_6, 2017/09

 Times Cited Count:1 Percentile:14.04

Particle and Heavy Ion Transport code System, PHITS, has been developed under the collaboration of several institutes in Japan and Europe. It can deal with the transport of nearly all particles up to 1 TeV (per nucleon for ion) using various nuclear reaction models and data libraries. More than 2,500 researchers and technicians have used the code for a variety of applications such as accelerator design, radiation shielding and protection, medical physics, and space and geosciences. This paper briefly summarizes physics models and functions newly implemented in PHITS between versions 2.52 and 2.82.

Journal Articles

Features of PHITS version 2.88

Sato, Tatsuhiko; Iwamoto, Yosuke; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Matsuda, Norihiro; Iwase, Hiroshi*; Niita, Koji*

Hoshasen, 43(2), p.55 - 58, 2017/05

Particle and Heavy Ion Transport code System, PHITS, has been developed under the collaboration of several institutes in Japan and Europe. It can deal with the transport of nearly all particles up to 1 TeV (per nucleon for ion) using various nuclear reaction models and data libraries. More than 2,500 registered researchers and technicians have used this system for various applications such as accelerator design, radiation shielding and protection, medical physics, and space- and geo-sciences. This paper summarizes the physics models and functions recently implemented in PHITS, between versions 2.52 and 2.88.

Journal Articles

Benchmark study of the recent version of the PHITS code

Iwamoto, Yosuke; Sato, Tatsuhiko; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Matsuda, Norihiro; Hosoyamada, Ryuji*; Niita, Koji*

Journal of Nuclear Science and Technology, 54(5), p.617 - 635, 2017/05

 Times Cited Count:14 Percentile:0.82(Nuclear Science & Technology)

We performed a benchmark study for 58 cases using the recent version 2.88 of the Particle and Heavy Ion Transport code System (PHITS) in the following fields: particle production cross-sections for nuclear reactions, neutron transport calculations, and electro-magnetic cascade. This paper reports details for 22 cases. In cases of nuclear reactions with energies above 100 MeV and electro-magnetic cascade, overall agreements were found to be satisfactory. On the other hand, PHITS did not reproduce the experimental data for an incident proton energy below 100 MeV, because the intranuclear cascade model INCL4.6 in PHITS is not suitable for the low-energy region. For proton incident reactions over 100 MeV, PHITS did not reproduce fission product yields due to the problem of high-energy fission process in the evaporation model GEM. To overcome these inaccuracies, we are planning to incorporate a high-energy version of the evaluated nuclear data library JENDL-4.0/HE, and so on.

Journal Articles

Overview of JENDL-4.0/HE and benchmark calculations

Kunieda, Satoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Minato, Futoshi; Okamoto, Tsutomu; Sato, Tatsuhiko; Nakashima, Hiroshi; Iwamoto, Yosuke; Iwamoto, Hiroki; Kitatani, Fumito; et al.

JAEA-Conf 2016-004, p.41 - 46, 2016/09

Neutron- and proton-induced cross-section data are required in a wide energy range beyond 20 MeV, for the design of accelerator applications. New evaluations are performed with recent knowledge in the optical and pre-equilibrium model calculations. We also evaluated cross-sections for p+$$^{6,7}$$Li and p+$$^{9}$$Be which have been highly requested from a medical field. The present high-energy nuclear data library, JENDL-4.0/HE, includes evaluated cross-sections for incident neutrons and protons up to 200 MeV (for about 130 nuclei). We overview substantial features of the library, i.e., (1) systematic evaluation with CCONE code, (2) challenges for evaluations of light nuclei and (3) inheritance of JENDL-4.0 and JENDL/HE-2007. In this talk, we also focus on the results of benchmark calculation for neutronics to show performance of the present library.

Journal Articles

Overview of the PHITS code and application to nuclear data; Radiation damage calculation for materials

Iwamoto, Yosuke; Sato, Tatsuhiko; Niita, Koji*; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Matsuda, Norihiro; Iwase, Hiroshi*; et al.

JAEA-Conf 2016-004, p.63 - 69, 2016/09

A general purpose Monte Carlo Particle and Heavy Ion Transport code System, PHITS, is being developed through the collaboration of several institutes. PHITS can deal with the transport of nearly all particles, including neutrons, protons, heavy ions, photons, and electrons, over wide energy ranges using various nuclear reaction models and data libraries. PHITS users apply the code to various research and development fields such as nuclear technology, accelerator design, medical physics, and cosmic-ray research. This presentation briefly summarizes the physics models implemented in PHITS, and introduces some new models such as muon-induced nuclear reaction model and a $$gamma$$ de-excitation model EBITEM. We will also present the radiation damage cross sections for materials, PKA spectra and kerma factors calculated by PHITS under the IAEA-CRP activity titled "Primary radiation damage cross section."

Journal Articles

Application of JAERI Quantum Molecular Dynamics model for collisions of heavy nuclei

Ogawa, Tatsuhiko; Hashimoto, Shintaro; Sato, Tatsuhiko; Niita, Koji*

EPJ Web of Conferences (Internet), 122, p.04005_1 - 04005_6, 2016/06

BB2015-0309.pdf:0.24MB

 Percentile:100

Nucleus-nucleus reactions models are important for radiological safety in heavy ions accelerator facilities such as heavy ion cancer therapy facilities. As one of such models, JAERI Quantum Molecular Dynamics (JQMD) has been successfully used to describe production of residue and secondary particles in nucleus-nucleus collisions. However, it has been pinpointed that formulation of interactions between nucleons were unstable through time evolution therefore heavy nuclei tended to decay before interactions. Such decays could not be distinguished from decay by collisions. In this study, we revised the description of interactions between nucleons to stabilize nuclei before collisions. Moreover, an algorithm to check the stability of ground-state nuclei was introduced. Description of nucleon-nucleon scattering cross sections were improved by introducing the in-medium effects. Fragment production cross sections for heavy targets (e.g. Ag) are predicted in better accuracy by thus developed revised JQMD (JQMD 2.0).

Journal Articles

Analysis of angular distribution of fragments in relativistic heavy-ion collisions by quantum molecular dynamics

Ogawa, Tatsuhiko; Sato, Tatsuhiko; Hashimoto, Shintaro; Niita, Koji*

EPJ Web of Conferences (Internet), 117, p.03011_1 - 03011_8, 2016/05

 Times Cited Count:1 Percentile:20.72

Accurate prediction of fragment angular distribution in nucleus-nucleus collisions is essential for theoretical studies on nuclei and applications of particle beam. Quantum molecular dynamics is one of the approaches often adopted in general purpose radiation transport simulation codes to simulate formation of fragments, however, it is suggested that they tend to overestimate the width of fragment distribution angle. It is true for JQMD, the nucleus-nucleus reaction event generator incorporated to PHITS. By revising the description of peripheral collisions prediction of fragments angular distribution has been improved. First, spurious disintegration of nuclei before interaction is inhibited by introducing relativistic-covariant kinematics. By this improvement, one can distinguish nucleus spuriously disintegrated and nuclei interacted with other nuclei. Second, nucleon-nucleon scattering cross sections were increased by the suppression of Pauli blocking effect in the nucleus outer region to take into account for the increase in nucleon-nucleon scattering cross section. As a result, revised JQMD (RJQMD) predicts fragment angular distribution of fragments better than JQMD.

Journal Articles

Overview of particle and heavy ion transport code system PHITS

Sato, Tatsuhiko; Niita, Koji*; Matsuda, Norihiro; Hashimoto, Shintaro; Iwamoto, Yosuke; Furuta, Takuya; Noda, Shusaku; Ogawa, Tatsuhiko; Iwase, Hiroshi*; Nakashima, Hiroshi; et al.

Annals of Nuclear Energy, 82, p.110 - 115, 2015/08

 Times Cited Count:7 Percentile:22.72(Nuclear Science & Technology)

The general purpose Monte Carlo Particle and Heavy Ion Transport code System, PHITS, is being developed through a collaboration of several institutes in Japan and Europe. The Japan Atomic Energy Agency is responsible for managing the entire project. PHITS can deal with the transport of nearly all particles, including neutrons, protons, heavy ions, photons, and electrons, over wide energy ranges using various nuclear reaction models and data libraries. This paper briefly summarizes the physics models implemented in PHITS, and introduces some important functions useful for particular purposes, such as an event generator mode and beam transport functions.

Journal Articles

Energy-dependent fragmentation cross sections of relativistic $$^{12}$$C

Ogawa, Tatsuhiko; Sato, Tatsuhiko; Hashimoto, Shintaro; Satoh, Daiki; Tsuda, Shuichi; Niita, Koji*

Physical Review C, 92(2), p.024614_1 - 024614_14, 2015/08

AA2015-0260.pdf:2.96MB

 Times Cited Count:16 Percentile:12.26(Physics, Nuclear)

For prediction of radiological impact of heavy ions in accelerator facilities, space missions and cancer therapy, nuclear reaction models play a fundamental role. As one of such models, JAERI Quantum molecular dynamics (JQMD) has been successfully used to describe production of residue and secondary particles in nucleus-nucleus collisions. However, it has been pinpointed that JQMD underestimates projectile-like fragments produced in peripheral collisions. Moreover, no cross section data systematically measured over a wide energy range are not available, which makes it difficult to benchmark the reaction models. In this study, we develop a method to measured fragmentation cross sections using a thick target and detecting fragments produced from incident ions fragmented in the target using telescope detectors. Thus we obtained fragmentation cross sections systematically over a wide energy range. We also revise the description of reaction mechanism and ground-state nuclear structure in JQMD to take into account for peripheral collisions accurately. So far, ground-state nuclei got excited and sometimes disintegrated owing to frame transform from the laboratory system to the center-of-mass system. Fragment production cross sections calculated by the revised JQMD (JQMD2.0) are in better agreement with the literature data.

Journal Articles

Improvements and developments of physics models in PHITS for space applications

Sihver, L.*; Sato, Tatsuhiko; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Niita, Koji*

Proceedings of IEEE Aerospace Conference 2015, 8 Pages, 2015/06

Precise predictions of the radiation environment inside space vehicles, and inside the human body, are essential when planning for long term deep space missions. Upgrading of nuclear reaction models in Particle and Heavy Ion Transport code System (PHITS) was essential for application to radiological protection in space. In this paper, we present some physics models which have been recently improved and developed in PHITS. The items introduced in this paper are improvements of Kurotama Hybrid model, adopting of the Intra-Nuclear Cascade of Liege (INCL) model, development of statistical multi-fragmentation model (SMM) and combining the INCL and the Distorted Wave Born Approximation (DWBA) calculation. The results of verification studies for these models are also presented.

Journal Articles

PHITS simulation of quasi-monoenergetic neutron sources from $$^7$$Li($$p$$,$$n$$) reactions

Hashimoto, Shintaro; Iwamoto, Osamu; Iwamoto, Yosuke; Sato, Tatsuhiko; Niita, Koji*

Energy Procedia, 71, p.191 - 196, 2015/05

 Times Cited Count:1 Percentile:17.62

Accelerator-based neutron sources using proton- and deuteron-induced reactions have been utilized for scientific and medical applications, such as irradiation testing of fusion reactor materials at IFMIF and BNCT. Quasi-monoenergetic neutron beams using $$^7$$Li($$p$$,$$n$$)$$^7$$Be are of special importance for calibrating a detector and measuring cross sections for neutron induced reactions. PHITS can deal with the transport of incident protons as well as secondary neutrons using various physics models, and it can estimate particle fluxes in the beam line and energy deposition in shielding materials. Therefore, PHITS is a useful code for neutron source design in accelerator facilities. However, nuclear reaction models implemented in PHITS, such as INC, were not enough to reproduce the peak structure in neutron spectra of experimental data, since these models do not consider the transition process of $$^7$$Li($$p$$,$$n$$)$$^7$$Be. We have developed a new option that adds peaks obtained by the DWBA method, which gives cross sections of the transition on the basis of quantum mechanics, to results calculated by the INC model. We had applied this option to estimate neutron spectra in the reactions at incident energies below 50 MeV. Results of the INC model using the option had been in good agreement with experimental data. In this study, we extended the applicable incident energy range up to 400 MeV for the $$^7$$Li($$p$$,$$xn$$) reactions. We will show the comparison between the calculated result and experimental data, and discuss the validity of the option for the reactions.

Journal Articles

New algorithm for Monte Carlo particle-transport simulation to recover event-by-event kinematic correlations of reactions emitting charged particles

Ogawa, Tatsuhiko; Sato, Tatsuhiko; Hashimoto, Shintaro; Niita, Koji*

Proceedings of Joint International Conference on Mathematics and Computation, Supercomputing in Nuclear Applications and the Monte Carlo Method (M&C + SNA + MC 2015) (CD-ROM), 11 Pages, 2015/04

We develop a new radiation transport calculation algorithm to recover event-by-event quantities based on inclusive cross-section data with conserving energy and momentum. In radiation transport calculations based on inclusive cross-section data, conventional algorithms could predict average behavior of the particles, however, they could not consider fluctuations around the average. Moreover, calculation of kinematics among secondary particles and recoiled residues resulted from reactions were out of their scope. To overcome these difficulties, we developed a new algorithm which reproduces particle emission in each reaction in exact accordance with the chosen reaction channel. The algorithm makes it possible to predict event-by-event quantities such as nuclear recoil, secondary particle and energy spectra, in all kinds of reaction channels. To evaluate the impact of the new algorithm, it was applied to various simulation studies such as dose conversion coefficient evaluation, soft-error analysis and radiation damage prediction. The calculated data shows that the new algorithm is indispensable for such simulation studies.

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