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Journal Articles

Development of a forward Monte Carlo based weight-window generator using the history-counter function in PHITS

Sato, Tatsuhiko; Hashimoto, Shintaro; M$'a$rquez Dami$'a$n, J. I.*; Niita, Koji*

Nuclear Instruments and Methods in Physics Research B, 557, p.165535_1 - 165535_8, 2024/12

 Times Cited Count:0

Journal Articles

In-situ measurement of radiation driven back-conversion from para to ortho liquid hydrogen state in cold moderators at J-PARC

Teshigawara, Makoto; Lee, Y.*; Tatsumoto, Hideki*; Hartl, M.*; Aso, Tomokazu; Iverson, E. B.*; Ariyoshi, Gen; Ikeda, Yujiro*; Hasegawa, Takumi*

Nuclear Instruments and Methods in Physics Research B, 557, p.165534_1 - 165534_10, 2024/12

 Times Cited Count:0

At Japanese Spallation Neutron Source in J-PARC, the para-hydrogen fraction was measured by using Raman spectroscopy in-situ for an integrated beam power of 9.4 MW$$cdot$$h at 1 MW operation, to evaluate the functionality of the ferric oxyhydroxide catalyst. This result showed that full functionality of the catalyst was retained up to the 1 MW operation. We attempted to study the effect of neutron scattering driven para to ortho-hydrogen back-conversion rate in the absence of the catalyst effect with a bypass line without catalyst. The measured increase of ortho-hydrogen fraction was 0.44% for an integrated beam power of 2.4 MW$$cdot$$h at 500 kW operation, however, which was considered to be due to not only to neutron collisions in cold moderators but also to the high ortho-hydrogen fraction of initially static liquid hydrogen in the bypass line and passive exudation of quasi-static hydrogen in the catalyst vessel to the main loop.

Journal Articles

Characterization of mineral composition using PIXE and EXAFS analyses to elucidate the Barium adsorption mechanism

Oguri, Kaori; Hagura, Naoto*; Yamaguchi, Akiko; Okumura, Masahiko; Matsuura, Haruaki*; Tsunashima, Yasumichi; Aoki, Katsumi; Arai, Yoichi; Watanabe, So

Nuclear Instruments and Methods in Physics Research B, 556, p.165516_1 - 165516_8, 2024/11

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Ningyo-toge is the uranium mine that has been operated in Japan. Various radioactive elements such as Uranium (U), and Radium (Ra) are still present in the mine ground water with very small amount, and behavior of those elements is not fully understood. In this study, we investigated the composition of metal oxides and clay minerals in a soil of slag deposit at the mine, and systematics of adsorption structure of various ions were examined. Identifying the composition and chemical forms of minerals present in the soil of slag can provide useful information for the safety assessment and evaluation of influence on the surrounding environment.

Journal Articles

Cathode shape dependence of gas ionization chamber on electron collection in $$Delta$$${it E}$ - ${it E}$ telescope ERDA

Harayama, Isao; Hirose, Yasushi*; Sekiba, Daiichiro*

Nuclear Instruments and Methods in Physics Research B, 554, p.165435_1 - 165435_6, 2024/09

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

$$Delta$$${it E}$-${it E}$ telescope elastic recoil detection analysis (ERDA) is a helpful ion beam analysis (IBA) technique for the absolute quantification of multiple light elements in thin films. We have developed a compact $$Delta$$${it E}$-${it E}$ telescope ERDA system to estimate a composition ratio of oxygen and nitrogen in metal oxynitride thin films. Our $$Delta$$${it E}$-${it E}$ telescope ERDA system employs a gas ionization chamber (GIC), which consisted of a U-shaped cathode, while a planar shaped cathode is widely utilized for GICs. The shape of U-shaped cathode is useful to downsize the GIC. The difference of performance between the U-shaped and planar shaped cathodes, however, has not been studied well, yet. In this study, we quantitatively evaluated the influence using the U-shaped cathode on $$Delta$$${it E}$-${it E}$ telescope ERDA. In order to compare the performance of the U-shaped and planar shaped cathode, we measured SrTiO$$_{3}$$ bulk samples as a standard with them. There is no significant difference between the two cathodes from the viewpoint of O recoil yields. These results show that the U-shaped cathode can also be used safely for $$Delta$$${it E}$-${it E}$ telescope ERDA, and that GICs have a flexibility in the electrode shape, which is useful to make GICs more compact.

Journal Articles

Ion beam induced luminescence of lanthanide complexes in organic solvents irradiated by hydrogen and argon ion beams

Nakahara, Masaumi; Watanabe, So; Ishii, Yasuyuki*; Yamagata, Ryohei*; Yuri, Yosuke*; Yuyama, Takahiro*; Ishizaka, Tomohisa*; Koka, Masashi*; Yamada, Naoto*; Hagura, Naoto*

Nuclear Instruments and Methods in Physics Research B, 554, p.165449_1 - 165449_5, 2024/09

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Ion beam induced luminescence analysis of lanthanide complexes in the organic solvents for minor actinides recovery process was carried out to investigate the structures of complexes. In this study, hydrogen ion beam obtained from the single-ended accelerator and argon ion beam obtained from the azimuthally varying field cyclotron were used in Takasaki Ion Accelerators for Advanced Radiation Application in National Institutes for Quantum Science and Technology. In the experiments, ion beam induced luminescence spectra of lanthanide complexes in the organic solvents were measured, and the relationship between the obtained spectra and the structures of complexes was studied.

Journal Articles

Adsorption mechanism of Eu onto newly synthesized fluorous-compound-impregnating adsorbent

Arai, Yoichi; Watanabe, So; Watanabe, Masayuki; Arai, Tsuyoshi*; Katsuki, Kenta*; Agou, Tomohiro*; Fujikawa, Hisaharu*; Takeda, Keisuke*; Fukumoto, Hiroki*; Hoshina, Hiroyuki*; et al.

Nuclear Instruments and Methods in Physics Research B, 554, p.165448_1 - 165448_10, 2024/09

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Journal Articles

Measurement of the response of a $$^6$$Li-glass detector to gamma rays by a coincidence method

Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Mochimaru, Takanori*; Hori, Junichi*; Terada, Kazushi*; Koizumi, Mitsuo

Nuclear Instruments and Methods in Physics Research A, 1064, p.169465_1 - 169465_9, 2024/07

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Journal Articles

Development of a radioactive substance detection system integrating a Compton camera and a LiDAR camera with a hexapod robot

Sato, Yuki; Kakuto, Takeshi*; Tanaka, Takayuki*; Shimano, Hiroyuki*; Morohashi, Yuko; Hatakeyama, Tomoyoshi*; Nakajima, Junsaku; Ishiyama, Masahiro

Nuclear Instruments and Methods in Physics Research A, 1063, p.169300_1 - 169300_7, 2024/06

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Journal Articles

Development of a practical tritiated water monitor to supervise the discharge of treated water from Fukushima Daiichi Nuclear Power Plant

Sanada, Yukihisa; Oshikiri, Keisuke*; Kanno, Marina*; Abe, Tomohisa

Nuclear Instruments and Methods in Physics Research A, 1062, p.169208_1 - 169208_7, 2024/05

 Times Cited Count:2 Percentile:94.57(Instruments & Instrumentation)

As part of the decommissioning work at the Fukushima Daiichi Nuclear Power Plant (FDNPP), the release of stored treated water began in 2023. In this study, we developed a practical tritium monitor to continuously monitor the concentration of tritiated water, as confirmed by batch sampling measurements at the FDNPP. The monitor is arranged with a flow cell detector comprising inexpensive plastic scintillator pellets and incorporating simultaneous measurements by three detectors, a veto detector, and lead shielding to reduce the influence of environmental $$gamma$$-rays. The system reached a detection limit of 911 Bq L-1 with a measurement time of 30 min, which is lower than the discharge standard for tritiated water of 1,500 Bq L-1. The system can also qualitatively distinguish the presence of disturbances due to interfering radionuclides other than tritium or background radiation using the $$beta$$-ray spectrum.

Journal Articles

First demonstration of a single-end readout position-sensitive optical fiber radiation sensor inside the Fukushima Daiichi Nuclear Power Station based on wavelength-resolving analysis

Terasaka, Yuta; Sato, Yuki; Uritani, Akira*

Nuclear Instruments and Methods in Physics Research A, 1062, p.169227_1 - 169227_6, 2024/05

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Journal Articles

Defect formation simulated by track structure calculation model

Ogawa, Tatsuhiko; Iwamoto, Yosuke

Nuclear Instruments and Methods in Physics Research B, 549, p.165255_1 - 165255_4, 2024/04

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Atomic defect is one of the critical factors that determines the irradiation effects in materials. The atoms are recoiled by the impulse of incoming radiation, which changes the mechanical, electrical and chemical properties of the target materials. Methods to calculate atomic displacement based on nuclear reaction cross sections and Rutherford scattering cross sections were proposed but they were dedicated to calculation of the defect density in macroscopic scale whereas some phenomena are attributed to the topological arrangements of defects in microscopic scale. Application of a track-structure calculation model, ITSART implemented to a general-purpose radiation transport code PHITS for calculation of the topological arrangement of radiation-induced defects is proposed in this study. To verify the defect production calculated by ITSART, DPA (Displacement Per Atom) cross section in Cu was calculated and compared with literature data. The agreement indicates the accuracy of ITSART for calculating atomic displacement. By using the same methodology to a smaller volume, the defects in SiO$$_{2}$$ exposed to 600 MeV proton beam was calculated. PHITS users can make use of the outputs by forwarding them to other tools, such as molecular dynamics codes, to analyse the further evolution of the defects.

Journal Articles

Development of wide range photon detection system for muonic X-ray spectroscopy

Mizuno, Rurie*; Niikura, Megumi*; Saito, Takeshi*; Matsuzaki, Teiichiro*; Sakurai, Hiroyoshi*; Amato, A.*; Asari, Shunsuke*; Biswas, S.*; Chiu, I.-H.; Gianluca, J.*; et al.

Nuclear Instruments and Methods in Physics Research A, 1060, p.169029_1 - 169029_14, 2024/03

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Journal Articles

Characterization of mineral insulated cables at the WWR-K reactor; First results

Shaimerdenov, A.*; Gizatulin, Sh.*; Sairanbayev, D.*; Bugybay, Zh.*; Silnyagin, P.*; Akhanov, A.*; Fuyushima, Takumi; Hirota, Noriaki; Tsuchiya, Kunihiko

Nuclear Instruments and Methods in Physics Research B, 548, p.165235_1 - 165235_6, 2024/03

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Compared to conditions in other types of installations, cable insulation in nuclear reactors is exposed to mixed conditions (high temperatures, radiation, pressure, humidity, aggressive environments) and at the same time they must maintain their performance characteristics for a long time (about 40-50 years). As a result of irradiation to such conditions, the electrical properties of the cable insulation are degraded, which leads to an increase in current loss. This is because the charge is induced by radiation into the insulator. At the WWR-K reactor, studies were started on the radiation resistance of signal cables with two types of mineral insulation (MgO and Al$$_{2}$$O$$_{3}$$). As part of these studies, new experimental data will be obtained on the behavior of signal cables with mineral insulation of two types in mixed operating conditions (radiation field and high temperature). It is planned to accumulate fluence of fast neutrons $$sim$$ 10$$^{20}$$cm$$^{-2}$$ in cables. The irradiation temperature will be (500 $$pm$$ 50)$$^{circ}$$C). The study of the degradation of the electrical properties of the insulation of signal cables will be carried out in real time (in-situ). For this, a special design of the experimental device and a technique for in-reactor measurement of electrical characteristics were developed. This paper presents a sketch of the capsule design, the results of complex calculations for the development of the capsule design, the expected neutron fluences, the dpa in steel, the technique for in-reactor measurement of electrical characteristics, and a work plan for the future indicating the expected results. The cable irradiation time until the target neutron fluence is reached will be about 100 effective days. This research is funded by the International Scientific-Technical Center.

Journal Articles

Changes in molecular conformation and electronic structure of DNA under $$^{12}$$C ions based on first-principles calculations

Sekikawa, Takuya; Matsuya, Yusuke; Hwang, B.*; Ishizaka, Masato*; Kawai, Hiroyuki*; Ono, Yoshiaki*; Sato, Tatsuhiko; Kai, Takeshi

Nuclear Instruments and Methods in Physics Research B, 548, p.165231_1 - 165231_6, 2024/03

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

One of the main causes of radiation effects on the human body is thought to be damage to DNA, which carries genetic information. However, it is not fully understood what kind of molecular structural changes DNA undergoes upon radiation damage. Since it has been reported that various types of DNA damage are formed when DNA is irradiated, our group has investigated the relationship between DNA damage and various patterns of radiation-induced ionization induced by radiation. Although we have so far analyzed DNA damage in a simple system using a rigid body model of DNA, more detailed calculations are required to analyze the molecular structural changes in DNA, which are considered to be important in considering the effects on the human body. In this study, we attempted to clarify the molecular conformational changes of DNA using OpenMX, a first-principles calculation software that can discuss electronic states based on molecular structures. Specifically, we calculated the most stable structure, band dispersion, and wave function of DNA under the assumption that one and two electrons are ionized by various radiation. In the presentation, we will discuss the relationship between the energy dependence of each incident radiation type and the molecular conformational change of DNA. In addition, the radiation-induced changes in the basic physical properties of DNA (corresponding to the initial stage of DNA damage) will be discussed from the viewpoints of both radiation physics and solid state physics.

Journal Articles

Development of 0.5 mm gauge size radial collimators for high-pressure neutron diffraction experiments at PLANET in J-PARC

Hattori, Takanori; Suzuki, Koji*; Miyo, Tatsuya*; Ito, Takayoshi*; Machida, Shinichi*

Nuclear Instruments and Methods in Physics Research A, 1059, p.168956_1 - 168956_9, 2024/02

 Times Cited Count:2 Percentile:65.72(Instruments & Instrumentation)

Radial collimators (RC) with a 0.5 mm gauge size (GS) were specially designed for high-pressure neutron diffraction experiments and their performance and efficacy were investigated. The RCs with nominal GS of 0.75 mm, 1.5 mm, and 3.0 mm effectively exhibited GS of 0.50 mm, 1.07 mm, and 2.78 mm, respectively. The transmissions of all three RCs were almost equivalent. The assessment using a P-E press and a DAC revealed that the anvil scattering was considerably minimized and the sample-to-anvil signal ratio reached values of 0.5 and 2.0 for the PE press and DAC, respectively, when using the 0.5 mm-GS RCs. These results indicate that the 0.5mm-GS RCs have been fabricated as intended and exhibit efficacy for the high-pressure-neutron diffraction experiments, specifically those exceeding 30 GPa. Among those ever manufactured for neutron scattering experiments, the RCs display the smallest GS.

Journal Articles

Development of a model for evaluating the luminescence intensity of phosphors based on the PHITS track-structure simulation

Hirata, Yuho; Kai, Takeshi; Ogawa, Tatsuhiko; Matsuya, Yusuke; Sato, Tatsuhiko

Nuclear Instruments and Methods in Physics Research B, 547, p.165183_1 - 165183_7, 2024/02

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

The luminescence efficiency of the phosphors for swift ions is known to decrease because of the quenching effects. To obtain the precise dose distributions using phosphor detectors, understanding the mechanisms of quenching effects is mandatory. Here, we developed a new model for estimating the luminescence intensity of phosphors based on the track-structure modes for arbitrary materials implemented in PHITS. The developed model enabled the simulation of the quenching effects of the BaFBr detector and was verified by comparing the results to the corresponding measured data. The present model is expected to contribute to developing phosphor detectors worldwide.

Journal Articles

Development of a large-area alpha imaging detector for hand and foot monitors

Morishita, Yuki; Higuchi, Mikio*; Kaneko, Junichi*; Kitagawa, Yuichi*; Akedo, Jun*; Soma, Mitsugu*; Matsui, Hiroaki*

Nuclear Instruments and Methods in Physics Research A, 1057, p.168702_1 - 168702_8, 2023/12

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

This paper describes the development of a large-area imaging detector capable of measuring the detailed distribution of alpha particles on hands and feet for use in entry/exit control monitors in decommissioning sites such as the Fukushima Daiichi Nuclear Power Plant. The detector was developed using a commercially available ZnS(Ag) scintillator and an electron multiplying CCD camera. The effectiveness of the detector was evaluated by measuring several types of radiation sources, and the results showed that it was possible to detect the position of alpha particles in a very short time, and contamination levels of up to 11 Bq/cm$$^{2}$$ could be visualized. As a result of the minimal detectable surface activity concentration evaluations, 2.0 minutes or more is required to achieve 4 Bq/cm$$^{2}$$, and 25.0 minutes or more is required to achieve 0.4 Bq/cm$$^{2}$$. The field of view of the detector was also checked, and it was confirmed that the setup had a field of view that could cover most of the hand and the sole of the shoe. This detector is expected to be useful for preventing internal uptake and decontamination.

Journal Articles

Development of scalable deconvolution methods for determining secondary target neutron yields from dual-thick-target cosmic-ray ion accelerator experiments

Ratliff, H.; McGirl, N. A.*; Beach, M. R.*; Castellanos, L. A.*; Clowdsley, M. S.*; Heilbronn, L. H.*; LaTessa, C.*; Norbury, J. W.*; Rusek, A.*; Sivertz, M.*; et al.

Nuclear Instruments and Methods in Physics Research B, 544, p.165121_1 - 165121_15, 2023/11

 Times Cited Count:0 Percentile:0.00(Instruments & Instrumentation)

Journal Articles

Neutron-production double-differential cross sections of $$^{rm nat}$$Pb and $$^{209}$$Bi in proton-induced reactions near 100 MeV

Iwamoto, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Ishi, Yoshihiro*; Uesugi, Tomonori*; Yashima, Hiroshi*; Nishio, Katsuhisa; Sugihara, Kenta*; $c{C}$elik, Y.*; et al.

Nuclear Instruments and Methods in Physics Research B, 544, p.165107_1 - 165107_15, 2023/11

 Times Cited Count:1 Percentile:41.04(Instruments & Instrumentation)

The lack of double-differential cross-section (DDX) data for neutron production below the incident proton energy of 200 MeV hinders the validation of spallation models in technical applications, such as research and development of accelerator-driven systems (ADSs). The present study aims to obtain experimental DDX data for ADS spallation target materials in this energy region and identify issues related to the spallation models by comparing them with the analytical predictions. The DDXs for the ($$p, xn$$) reactions of $$^{rm nat}$$Pb and $$^{209}$$Bi in the 100-MeV region were measured over an angular range of 30$$^{circ}$$ to 150$$^{circ}$$ using the time-of-flight method. The measurements were conducted at Kyoto University utilizing the FFAG accelerator. The DDXs obtained were compared with calculation results from Monte Carlo-based spallation models and the evaluated nuclear data library, JENDL-5. Comparison between the measured DDX and analytical values based on the spallation models and evaluated nuclear data library indicated that, in general, the CEM03.03 model demonstrated the closest match to the experimental values. Additionally, the comparison highlighted several issues that need to be addressed in order to improve the reproducibility of the proton-induced neutron-production DDX in the 100 MeV region by these spallation models and evaluated nuclear data library.

Journal Articles

Neutron resonance fission neutron analysis for nondestructive fissile material assay

Hironaka, Kota; Lee, J.; Koizumi, Mitsuo; Ito, Fumiaki*; Hori, Junichi*; Terada, Kazushi*; Sano, Tadafumi*

Nuclear Instruments and Methods in Physics Research A, 1054, p.168467_1 - 168467_5, 2023/09

 Times Cited Count:2 Percentile:41.04(Instruments & Instrumentation)

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