Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 1212

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Remote alpha/beta measurement system with support vector machine algorithm

Morishita, Yuki; Miyamura, Hiroko; Sato, Yuki; Matsubara, Jun*; Sumali, B.*; Mitsukura, Yasue*

Nuclear Instruments and Methods in Physics Research A, p.170368_1 - 170368_16, 2025/03

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

Decommissioning nuclear reactor sites presents challenges due to the presence of various radionuclides, including alpha emitters (e.g., Pu, Am, Cm) and beta emitters (e.g., $$^{137}$$Cs, $$^{90}$$Sr-$$^{90}$$Y), which pose significant internal exposure risks to workers. Traditional measurement methods require multiple instruments and are time-consuming, particularly in high gamma-ray environments. To address these issues, we developed a remote alpha and beta discrimination measurement system that integrates a stilbene scintillator detector with a silicon photomultiplier, enabling simultaneous detection of both alpha and beta particles. This study further incorporates machine learning techniques, specifically Support Vector Machines (SVM), for automatic discrimination, eliminating the need for user-defined thresholds and ensuring consistent operational conditions. The system was tested with known radiation sources, demonstrating over 96% classification accuracy for alpha and beta particles. Measurements conducted in motion effectively identified contamination sources, confirming the system's capability for real-time analysis. This innovative approach enhances radiation safety and efficiency in nuclear decommissioning operations, making it particularly beneficial in environments where human access is limited.

Journal Articles

Evaluation of the performance of event reconstruction algorithms in the JSNS$$^2$$ experiment using a $$^{252}$$Cf calibration source

Lee, D. H.*; Dodo, Taku; Haga, Katsuhiro; Harada, Masahide; Hasegawa, Shoichi; Kasugai, Yoshimi; Kinoshita, Hidetaka; Masuda, Shiho; Meigo, Shinichiro; Sakai, Kenji; et al.

Nuclear Instruments and Methods in Physics Research A, 1072, p.170216_1 - 170216_6, 2025/03

 Times Cited Count:2 Percentile:98.29(Instruments & Instrumentation)

Journal Articles

Evaluation of the distribution accuracy of radioactivity from a gamma-ray source using an omnidirectional detector for radiation imaging with fractal geometry

Sasaki, Miyuki; Abe, Yuki*; Sanada, Yukihisa; Torii, Tatsuo*

Nuclear Instruments and Methods in Physics Research A, 1072, p.170207_1 - 170207_12, 2025/03

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

We have developed an omnidirectional radiation imager with fractal geometry named the FRIE system. This paper presents the development and evaluation of the FRIE system, designed to accurately estimate radioactivity distribution within decommissioning environments, such as the Fukushima Daiichi Nuclear Power Station. The FRIE system is a unit of tetrahedral radiation sensors; 16 sensors are arranged in a Sierpinski tetrahedron shape, and the space between the sensors is filled with tungsten-based alloy for radiation shielding. This study assessed the performance of the FRIE system in estimating radiation distribution through simulations and actual measurement tests. From the results of the simulations and experimental data, it was confirmed that by maintaining a measurement density of at least 2 points/m$$^{2}$$, limiting the positional error to within $$pm$$10 cm, and the angular error to within $$pm$$10 degrees, it is possible to estimate the source location with an angular resolution of approximately 30 degrees. Future improvements in the arrangement of the FRIE system's crystals and shielding should enhance the performance metrics. This research signifies a pioneering implementation of fractal-based radiation imaging technology, offering a new direction in radiation measurement.

Journal Articles

Monte Carlo and experimental assessment of the optimal geometry of the source and collimator for a table-top NRTA system for small nuclear material measurement

Guembou Shouop, C. J.; Tsuchiya, Harufumi

Nuclear Instruments and Methods in Physics Research A, 1072, p.170189_1 - 170189_14, 2025/03

 Times Cited Count:1 Percentile:52.60(Instruments & Instrumentation)

Journal Articles

In-situ detection of high-energy beta ray emitter $$^{90}$$Sr/$$^{90}$$Y inside the Fukushima Daiichi Nuclear Power Station Unit 3 reactor building using a liquid light guide Cherenkov counter

Terasaka, Yuta; Sato, Yuki; Furuta, Yoshihiro*; Kubo, Shin*; Ichiba, Yuta*

Nuclear Instruments and Methods in Physics Research A, 1070, Part 2 , p.170021_1 - 170021_9, 2025/01

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

Journal Articles

Validation of crystal surface scattering method for downsizing accelerator mass spectrometry

Jinno, Satoshi; Matsubara, Akihiro*; Fujita, Natsuko; Kimura, Kenji

Nuclear Instruments and Methods in Physics Research B, 557, p.165545_1 - 165545_4, 2024/12

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

This study introduces the development of a downsized Accelerator Mass Spectrometry (AMS) system aiming to enhance accessibility and cost-effectiveness in radiocarbon analysis. The "crystal surface stripper method" is introduced as a solution to challenges in AMS downsizing, demonstrating effective ion detection with a smaller angular spread compared to conventional gas stripper methods. The experimental results provide insights into charge conversion capabilities, scattering angle broadening, and energy loss associated with surface scattering.

Journal Articles

Measurements of displacement cross sections of metals for 120-GeV proton beam irradiation

Iwamoto, Yosuke; Matsuda, Hiroki*; Meigo, Shinichiro; Yonehara, Katsuya*; Pellemoine, F.*; Liu, Z.*; Lynch, K.*; Yoshida, Makoto*; Yabuuchi, Atsushi*; Yoshiie, Toshimasa*; et al.

Nuclear Instruments and Methods in Physics Research B, 557, p.165543_1 - 165543_8, 2024/12

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

The number of displacements per atom is widely used as an indicator of irradiation damage to materials in proton accelerator facilities. Experiments have been carried out on protons below 3 GeV to verify the dpa of metallic materials. However, the dpa for high-energy protons above 3 GeV has not been measured. In order to validate the displacement cross sections of metals in the high-energy region, the electrical resistivity changes of aluminium, copper and tungsten wires at a temperature of 8 K were measured using protons with energy of 120 GeV. The results show that the conventional irradiation damage model of PHITS overestimates the experimental data. On the other hand, the calculation results using the athermal recombination correction model were in agreement with the experimental data.

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 Percentile:0.00(Instruments & Instrumentation)

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:1 Percentile:0.00(Instruments & Instrumentation)

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

Investigation on the $$Omega(2012)$$ from QCD sum rules

Su, N.*; Chen, H.-X.*; Gubler, P.; Hosaka, Atsushi

Nuclear and Particle Physics Proceedings, 347, p.2 - 5, 2024/12

Journal Articles

Using X-ray absorption near edge structure to evaluate adsorption properties of rare earths and nitrogen by difference of their interactions

Minowa, Kazuki*; Watanabe, So; Nakase, Masahiko*; Takahatake, Yoko; Miyazaki, Yasunori; Ban, Yasutoshi; Matsuura, Haruaki*

Nuclear Instruments and Methods in Physics Research B, 556, p.165496_1 - 165496_6, 2024/11

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

In this study, X-ray absorption near edge structure (XANES) spectral analysis and column experiments were used to verify the selectivity of rare earth (RE) ions by alkyl diamide amine (ADAAM) adsorbent. In addition, the interactions between the N atoms of ADAAM and RE ions were evaluated to determine whether any of the RE ions are a valid simulant for developing a mutual separation process for minor actinides (MAs) in highly radioactive liquid waste. It was confirmed that La and Ce interacted with the amine N atom of ADAAM and they showed a peak shift of the N-K edge XANES spectrum; this finding suggested that a soft interaction is an essential factor influencing ion selectivity. Therefore, the selection factor of RE ions by ADAAM adsorbent was similar to that of MAs. It was concluded that RE ions are reasonable species to simulate MAs.

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

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

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

Measurement of Naturally-Occurring Radioactive Materials (NORM) using a scintillator-based alpha detector

Morishita, Yuki; Tomioka, Akifumi; Fujisawa, Makoto; Izaki, Kenji

Nuclear Instruments and Methods in Physics Research A, 1065, p.169527_1 - 169527_5, 2024/08

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

It is important to differentiate between natural and artificial radioactive materials such as plutonium in nuclear facilities. In this study, a scintillator-based alpha-particle detector was developed using YAP:Ce scintillator and Multi-Anode PhotoMultiplier Tube. The detector was used to measure various naturally occurring radioactive materials (NORM) samples including radon progeny, lead plate, lantern mantle, and radium ceramic ball. The measurement results were compared with Monte Carlo simulation calculations and were found to be in agreement. The energy resolution of the detector is 8.6%FWHM. In the measurement results of radon progeny, peaks of $$^{212}$$Bi (6.1 MeV), $$^{214}$$Po (7.7 MeV), and $$^{212}$$Po (8.8 MeV) can be observed. The lead plate contains $$^{210}$$Po and emits 5.3 MeV alpha particle. The simulation with the same energy was able to reproduce the actual measurement. The results showed the energy and distribution of the alpha particles emitted by the NORM samples. The study successfully demonstrated the capability of the developed alpha-particle detector in identifying NORM.

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

Pushing the high count rate limits of scintillation detectors for challenging neutron-capture experiments

Balibrea-Correa, J.*; Kimura, Atsushi; 133of others*

Nuclear Instruments and Methods in Physics Research A, 1064, p.169385_1 - 169385_13, 2024/07

 Times Cited Count:3 Percentile:86.15(Instruments & Instrumentation)

Journal Articles

Corrigendum to "Development of 0.5 mm gauge size radial collimators for high-pressure neutron diffraction experiments at PLANET in J-PARC" [Nucl. Instrum. Methods Phys. Res. A 1059 (2024) 168956]

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

Nuclear Instruments and Methods in Physics Research A, 1064, p.169448_1 - 169448_9, 2024/07

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

The authors regret that the abstract and summary explain that the cup diameter of a standard double-toroidal anvils is 1.5 mm. This is incorrect; the standard diameter is 4.0 mm. The authors would like to apologise for any inconvenience caused.

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:3 Percentile:86.15(Instruments & Instrumentation)

1212 (Records 1-20 displayed on this page)