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Journal Articles

Radiological estimation and validation for the Accelerator-Based Boron Neutron Capture Therapy Facility at the Ibaraki Neutron Medical Research Center

Nakashima, Hiroshi; Nakamura, Takemi; Kobayashi, Hitoshi*; Tanaka, Susumu*; Kumada, Hiroaki*

NEA/NSC/R(2021)2 (Internet), p.142 - 151, 2021/12

Aiming of development of facilities for boron neutron capture therapy (BNCT) that can be installed in hospitals, an accelerator-based BNCT facility is being developed at the Ibaraki Neutron Medical Research Center under a collaboration among the Japan Atomic Energy Agency, the High Energy Accelerator Research Organization, the University of Tsukuba, and other institutions. It consists of a proton accelerator, having a maximum beam power of 80 kW, and a target, moderator, collimator and shield (TMCS) system. For the design concept, to satisfy the BNCT beam conditions and achieve a low activation, the radiation behavior in the TMCS system was simulated by the Monte Carlo method and this system configuration was optimized accordingly. In addition, the radiation estimation of the TMCS system was verified via several experiments and its applicability for BNCT was proved. This report reviews the estimation and validation studies for the development of the accelerator-based BNCT facility.

JAEA Reports

Interim activity status report of "the group for investigation of reasonable safety assurance based on graded approach" (from September, 2019 to September, 2020)

Yonomoto, Taisuke; Nakashima, Hiroshi*; Sono, Hiroki; Kishimoto, Katsumi; Izawa, Kazuhiko; Kinase, Masami; Osa, Akihiko; Ogawa, Kazuhiko; Horiguchi, Hironori; Inoi, Hiroyuki; et al.

JAEA-Review 2020-056, 51 Pages, 2021/03

JAEA-Review-2020-056.pdf:3.26MB

A group named as "The group for investigation of reasonable safety assurance based on graded approach", which consists of about 10 staffs from Sector of Nuclear Science Research, Safety and Nuclear Security Administration Department, departments for management of nuclear facility, Sector of Nuclear Safety Research and Emergency Preparedness, aims to realize effective graded approach (GA) about management of facilities and regulatory compliance of JAEA. The group started its activities in September, 2019 and has had discussions through 10 meetings and email communications. In the meetings, basic ideas of GA, status of compliance with new regulatory standards at each facility, new inspection system, etc were discussed, while individual investigation at each facility were shared among the members. This report is compiled with expectation that it will help promote rational and effective safety management based on GA by sharing contents of the activity widely inside and outside JAEA.

Journal Articles

Topics from radiation safety design of J-PARC

Nakashima, Hiroshi

JAEA-Conf 2020-001, p.69 - 74, 2020/12

J-PARC (Japan Proton Accelerator Research Complex) is a high-energy proton accelerator complex of the world's highest beam power. Because of its very high beam power and its high energy as well as the large-scale accelerator complex, we encountered some very difficult problems on radiation safety design. Various examinations and countermeasures were considered in order to overcome the difficulty. This paper introduces some of them. In addition, some new knowledge obtained during 10 years after completion are described.

Journal Articles

Neutron emission spectrum from gold excited with 16.6 MeV linearly polarized monoenergetic photons

Kirihara, Yoichi; Nakashima, Hiroshi; Sanami, Toshiya*; Namito, Yoshihito*; Itoga, Toshiro*; Miyamoto, Shuji*; Takemoto, Akinori*; Yamaguchi, Masashi*; Asano, Yoshihiro*

Journal of Nuclear Science and Technology, 57(4), p.444 - 456, 2020/04

 Times Cited Count:4 Percentile:62.49(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Shielding performance of newly developed boron-loaded concrete for DT neutrons

Sato, Satoshi*; Konno, Chikara; Nakashima, Hiroshi; Shionaga, Ryosuke*; Nose, Hiroyuki*; Ito, Yuji*; Hashimoto, Hirohide*

Journal of Nuclear Science and Technology, 55(4), p.410 - 417, 2018/04

 Times Cited Count:1 Percentile:11.6(Nuclear Science & Technology)

In order to enhance the neutron shielding performance, we developed concrete with boron of more than 10 wt%. We performed a neutron shielding experiment using the mockup of the newly developed boron-loaded concrete and DT neutrons at FNS in JAEA, and measured the reaction rates of the $$^{93}$$Nb(n,2n)$$^{92m}$$Nb and $$^{197}$$Au(n,$$gamma$$)$$^{198}$$Au reactions in the mockup. The calculations were conducted by using MCNP-5.14 and FENDL-2.1. The calculation results agreed well with the measured ones, and we confirmed that the accuracy was very good on the atomic composition data of the boron-loaded concrete and their nuclear data. In addition, we calculated effective dose rates and reaction rates of the $$^{59}$$Co(n,$$gamma$$)$$^{60}$$Co and $$^{151}$$Eu(n,$$gamma$$)$$^{152}$$Eu reactions in the boron-loaded concrete and other concretes. It is concluded that the boron-loaded concrete has much better shielding performance for DT neutrons than other concretes.

Journal Articles

Introduction to radiation physics; Third revised edition

Tada, Junichiro*; Nakashima, Hiroshi; Hayano, Ryugo*; Kobayashi, Hitoshi*; Asano, Yoshihiro*

Wakariyasui Hoshasen Butsurigaku; Kaitei 3-Han, 305 Pages, 2018/03

This book is an introduction to radiation physics. Under the concept of "linking physics of high school and radiation physics" for readers with high school graduation degree, we are doing simple commentary on the basis of qualitative explanation as much as possible. This book begins with "What is Radiation Physics", and consists of 12 chapters, including introductory special relativity, introductory quantum theory, structures of atoms and nuclei, radiations, radioactivity, interactions between radiation and matter, accelerators, radiation dose and so on.

Journal Articles

Characterization of the PTW 34031 ionization chamber (PMI) at RCNP with high energy neutrons ranging from 100 - 392 MeV

Theis, C.*; Carbonez, P.*; Feldbaumer, E.*; Forkel-Wirth, D.*; Jaegerhofer, L.*; Pangallo, M.*; Perrin, D.*; Urscheler, C.*; Roesler, S.*; Vincke, H.*; et al.

EPJ Web of Conferences, 153, p.08018_1 - 08018_5, 2017/09

 Times Cited Count:0 Percentile:0.03

At CERN, gas-filled ionization chambers PTW-34031 (PMI) are commonly used in radiation fields including neutrons, protons and $$gamma$$-rays. A response function for each particle is calculated by the radiation transport code FLUKA. To validate a response function to high energy neutrons, benchmark experiments with quasi mono-energetic neutrons have been carried out at RCNP, Osaka University. For neutron irradiation with energies below 200 MeV, very good agreement was found comparing the FLUKA simulations and the measurements. In addition it was found that at proton energies of 250 and 392 MeV, results calculated with neutron sources underestimate the experimental data due to a non-negligible gamma component originating from the target $$^{7}$$Li(p,n)Be reaction.

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

Characteristics of radiation-resistant real-time neutron monitor for accelerator-based BNCT

Nakamura, Takemi; Sakasai, Kaoru; Nakashima, Hiroshi; Takamiya, Koichi*; Kumada, Hiroaki*

Journal of Radiation Protection and Research, 41(2), p.105 - 109, 2016/06

no abstracts in English

Journal Articles

Progress and prospects of calculation methods for radiation shielding

Hirayama, Hideo*; Nakashima, Hiroshi; Morishima, Makoto*; Uematsu, Mikio*; Sato, Osamu*

Journal of Nuclear Science and Technology, 52(11), p.1339 - 1361, 2015/11

AA2014-0681.pdf:1.15MB

 Times Cited Count:6 Percentile:20.83(Nuclear Science & Technology)

Progress in calculation methods for radiation shielding are reviewed based on basis of the activities of research committees related to radiation shielding fields established in the Atomic Energy Society of Japan. A technological roadmap for the field of radiation shielding, progress and prospects for specific shielding calculation methods such as the Monte Carlo, discrete ordinate Sn transport, and simplified methods, and shielding experiments used to validate calculation methods are presented in this paper.

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:27 Percentile:93.57(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

Activation, Radiation shielding materials

Sukegawa, Atsuhiko; Iida, Hiromasa*; Itoga, Toshio*; Okumura, Keisuke; Kai, Tetsuya; Konno, Chikara; Nakashima, Hiroshi; Nakamura, Takashi*; Ban, Shuichi*; Yashima, Hiroshi*; et al.

Hoshasen Shahei Handobukku; Kisohen, p.299 - 356, 2015/03

no abstracts in English

Journal Articles

Overview of particle and heavy ion transport code system PHITS

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

JAEA-Conf 2014-002, p.69 - 74, 2015/02

A general purpose Monte Carlo Particle and Heavy Ion Transport code System, PHITS, is being developed through the collaboration of several institutes in Japan and Europe. 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. All components of PHITS such as its source, executable and data-library files are assembled in one package and then distributed to many countries. More than 1,000 researchers 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 important functions for specific applications, such as an event generator mode and a radiation damage calculation function.

Journal Articles

Measurements and parameterization of neutron energy spectra from targets bombarded with 120 GeV protons

Kajimoto, Tsuyoshi*; Shigyo, Nobuhiro*; Sanami, Toshiya*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Lee, H. S.*; Soha, A.*; Ramberg, E.*; Coleman, R.*; Jensen, D.*; et al.

Nuclear Instruments and Methods in Physics Research B, 337, p.68 - 77, 2014/10

 Times Cited Count:4 Percentile:38.2(Instruments & Instrumentation)

The energy spectra of neutrons were measured by a time-of-flight method for 120 GeV protons on thick graphite, aluminum, copper, and tungsten targets with an NE213 scintillator at the Fermilab Test Beam Facility. Neutron energy spectra were obtained between 25 and 3000 MeV at emission angles of 30, 45, 120, and 150$$^{circ}$$. The spectra were parameterized as neutron emissions from three moving sources and then compared with theoretical spectra calculated by PHITS and FLUKA codes. The yields of the theoretical spectra were substantially underestimated compared with the yields of measured spectra. The integrated neutron yields from 25 to 3000 MeV calculated with PHITS code were 16-36% of the experimental yields and those calculated with FLUKA code were 26-57% of the experimental yields for all targets and emission angles.

Journal Articles

Measurement of neutron energy spectra behind shields for quasi-monoenergetic neutrons generated by 246-MeV and 389-MeV protons using a Bonner sphere spectrometer

Matsumoto, Tetsuro*; Masuda, Akihiko*; Nishiyama, Jun*; Harano, Hideki*; Iwase, Hiroshi*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Yashima, Hiroshi*; Nakane, Yoshihiro; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.332 - 336, 2014/04

Recently, many high-energy accelerators are used for various fields. Shielding data for high-energy neutrons are therefore very important from the point of view of radiation protection in high energy accelerator facilities. However, the shielding experimental data for high energy neutrons above 100 MeV are very poor both in quality and in quantity. In this study, neutron penetration spectral fluence and ambient dose through iron and concrete shields were measured with a Bonner sphere spectrometer (BSS). Quasi-monoenergetic neutrons were produced by the $$^{7}$$Li(p,xn) reaction by bombarding a 1-cm thick Li target with 246-MeV and 389-MeV protons in the Research Center for Nuclear Physics (RCNP) of the Osaka University. Shielding materials are iron blocks with a thickness from 10 cm to 100 cm and concrete blocks with a thickness from 25 cm to 300 cm.

Journal Articles

Shielding benchmark experiment using hundreds of MeV quasi-monoenergetic neutron source by a large organic scintillator

Hagiwara, Masayuki*; Iwase, Hiroshi*; Iwamoto, Yosuke; Satoh, Daiki; Matsumoto, Tetsuro*; Masuda, Akihiko*; Yashima, Hiroshi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Sakamoto, Yukio; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.327 - 331, 2014/04

We have developed several hundreds of MeV p-$$^{7}$$Li quasi-monoenergetic neutron fields in the Research Center for Nuclear Physics (RCNP), Osaka University, Japan. In this study, we extended the measurements to higher energy with a p-$$^{7}$$Li quasi-monoenergetic neutron source, which was produced from a 1.0-cm-thick lithium target bombarded with 246 and 389 MeV protons, using a larger NE213 scintillator of 25.4-cm in diameter and 25.4-cm in thickness. The large NE213 have good energy resolution for high energy neutrons, because it can stop recoil protons up to 180 MeV. The measured data are compared with the Monte-Carlo codes (PHITS with JENDL-HE data library) in the energy spectra, time spectra and the attenuation length of the peak neutrons. This comparison shows good agreement between experiments and calculations. The attenuation length estimated from the well-fitted curves with single exponential form will be useful for the practical shielding design of high energy accelerator facilities.

Journal Articles

Response measurement of various neutron dose equivalent monitors in 134-387 MeV neutron fields

Nakane, Yoshihiro; Hagiwara, Masayuki*; Iwamoto, Yosuke; Iwase, Hiroshi*; Satoh, Daiki; Sato, Tatsuhiko; Yashima, Hiroshi*; Matsumoto, Tetsuro*; Masuda, Akihiko*; Nunomiya, Tomoya*; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.704 - 708, 2014/04

no abstracts in English

Journal Articles

Research activities on JASMIN; Japanese and American Study of Muon Interaction and Neutron detection

Nakashima, Hiroshi; Mokhov, N.*; 28 of others*

Progress in Nuclear Science and Technology (Internet), 4, p.191 - 196, 2014/04

In JASMIN, a series of experiments has been performed with the intense 120-GeV proton beams at Fermilab. The secondary particles created in such interactions were measured around the targets as well as in their penetration through steel, concrete and rock. Nuclear data such as activation and mass distributions of residual nuclei have been measured by activation methods. Double differential neutron production yield has also been measured by a time of flight techniques. Comparison of results calculated by PHITS and MARS reveals in general a good agreement. Further analyses are in progress.

Journal Articles

Overview of the PHITS code and its application to medical physics

Sato, Tatsuhiko; Niita, Koji*; Matsuda, Norihiro; Hashimoto, Shintaro; Iwamoto, Yosuke; Noda, Shusaku; Iwase, Hiroshi*; Nakashima, Hiroshi; Fukahori, Tokio; Chiba, Satoshi; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.879 - 882, 2014/04

PHITS is a general purpose 3-dimensional Monte-Carlo particle transport simulation code developed under collaboration of Japan Atomic Energy Agency (JAEA), Research Organization for Information Science and Technology (RIST), High Energy Accelerator Research Organization (KEK) and a couple of other institutes in Japan and Sweden. General features of the PHITS code together with details of the established model will be presented at the meeting.

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