Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 58

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

Development of a user-friendly interface IRONS for atmospheric dispersion database for nuclear emergency preparedness based on the Fukushima database

El-Asaad, H.*; Nagai, Haruyasu; Sagara, Hiroshi*; Han, C. Y.*

Annals of Nuclear Energy, 141, p.107292_1 - 107292_9, 2020/06

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

Atmospheric dispersion simulations can provide crucial information to assess radioactive plumes in the environment for nuclear emergency preparedness. However, it is a difficult and time-consuming task to make simulations assuming many possible scenarios and to derive data from a vast number of results. Therefore, an interface was developed to assist users in conveying characteristics of plumes from simulation results. The interface uses a large database that contains WSPEEDI-II simulations for the first 20-days of radioactive release from the Fukushima Daiichi Nuclear Power Plant, and it displays essential quantitative data to the user from the database. The user may conduct sensitivity analysis with the help of the interface by changing release condition to generate many different case scenarios.

Journal Articles

Computation speeds and memory requirements of mesh-type ICRP reference computational phantoms in Geant4, MCNP6, and PHITS

Yeom, Y. S.*; Han, M. C.*; Choi, C.*; Han, H.*; Shin, B.*; Furuta, Takuya; Kim, C. H.*

Health Physics, 116(5), p.664 - 676, 2019/05

 Times Cited Count:3 Percentile:12.61(Environmental Sciences)

Recently, Task Group 103 of the ICRP developed the mesh-type reference computational phantoms (MCRPs), which are planned for use in future ICRP dose coefficient calculation. Performance of major Monte Carlo particle transport codes (Geant4, MCNP6, and PHITS) were tested with MCRP. External and internal exposure of various particles and energies were calculated and the computational times and required memories were compared. Additionally calculation for voxel-mesh phantom was also conducted so that the influence of different mesh-representation in each code was studied. Memory usage of MRCP was as large as 10 GB with Geant4 and MCNP6 while it is much less with PHITS (1.2 GB). In addition, the computational time required for MRCP tends to increase compared to voxel-mesh phantoms with Geant4 and MCNP6 while it is equal or tends to decrease with PHITS.

Journal Articles

Mechanism of hardening and damage initiation in oxygen embrittlement of body-centred-cubic niobium

Yang, P.-J.*; Li, Q.-J.*; Tsuru, Tomohito; Ogata, Shigenobu*; Zhang, J.-W.*; Sheng, H.-W.*; Shan, Z.-W.*; Sha, G.*; Han, W.-Z.*; Li, J.*; et al.

Acta Materialia, 168, p.331 - 342, 2019/04

 Times Cited Count:8 Percentile:6.76(Materials Science, Multidisciplinary)

Body-centred-cubic metallic materials, such as niobium (Nb) and other refractory metals, are prone to embrittlement due to low levels of oxygen solutes. The mechanisms responsible for the oxygen-induced rampant hardening and damage are unclear. Here we illustrate that screw dislocations moving through a random repulsive force field imposed by impurity oxygen interstitials readily form cross-kinks and emit excess vacancies in Nb. The vacancies bind strongly with oxygen and screw dislocation in a three-body fashion, rendering dislocation motion difficult and hence pronounced dislocation storage and hardening. This leads to unusually high strain hardening rates and fast breeding of nano-cavities that underlie damage and failure.

Journal Articles

Battery-free, skin-interfaced microfluidic/electronic systems for simultaneous electrochemical, colorimetric, and volumetric analysis of sweat

Bandodkar, A. J.*; Gutruf, P.*; Choi, J.*; Lee, K.-H.*; Sekine, Yurina; Reeder, J. T.*; Jeang, W. J.*; Aranyosi, A. J.*; Lee, S. P.*; Model, J. B.*; et al.

Science Advances (Internet), 5(1), p.eaav3294_1 - eaav3294_15, 2019/01

 Times Cited Count:71 Percentile:0.15(Multidisciplinary Sciences)

Interest in advanced wearable technologies increasingly extends beyond systems for biophysical measurements to those that enable continuous, non-invasive monitoring of biochemical markers in biofluids. Here, we introduce battery-free, wireless microelectronic platforms that perform sensing via schemes inspired by the operation of biofuel cells. Combining these systems in a magnetically releasable manner with chrono-sampling microfluidic networks that incorporate assays based on colorimetric sensing yields thin, flexible, lightweight, skin-interfaced technologies with broad functionality in sweat analysis. A demonstration device allows simultaneous monitoring of sweat rate/loss, along with quantitative measurements of pH and of lactate, glucose and chloride concentrations using biofuel cell and colorimetric approaches.

Journal Articles

Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks

Finsterle, S.*; Lanyon, B.*; ${AA}$kesson, M.*; Baxter, S.*; Bergstr$"o$m, M.*; Bockg${aa}$rd, N.*; Dershowitz, W.*; Dessirier, B.*; Frampton, A.*; Fransson, ${AA}$.*; et al.

Geological Society, London, Special Publications, No.482, p.261 - 283, 2019/00

 Times Cited Count:2 Percentile:23.33

Nuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components which in many cases includes a bentonite buffer surrounding waste packages and the host rock. An SKB's (Swedish Nuclear Fuel and Waste Management Co.) Modelling Task Force project facilitated to improve the overall understanding of rock - bentonite interactions, as 11 teams used different conceptualisations and modelling tools to analyse the in-situ experiment at the $"A$ps$"o$ Hard Rock Laboratory. The exercise helped identify conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems and of aspects that need to be better understood to arrive at reliable predictions of bentonite wetting.

Journal Articles

Numerical simulation on self-leveling behavior of mixed particle beds using multi-fluid model coupled with DEM

Phan, L. H. S.*; Ohara, Yohei*; Kawata, Ryo*; Liu, X.*; Liu, W.*; Morita, Koji*; Guo, L.*; Kamiyama, Kenji; Tagami, Hirotaka

Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 12 Pages, 2018/10

Self-leveling behavior of core fuel debris beds is one of the key phenomena for the safety assessment of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The SIMMER code has been developed for CDA analysis of SFRs, and the code has been successfully applied to numerical simulations for key thermal-hydraulic phenomena involved in CDAs as well as reactor safety assessment. However, in SIMMER's fluid-dynamics model, it is always difficult to represent the strong interactions between solid particles as well as the discrete particle characteristics. To solve this problem, a new method has been developed by combining the multi-fluid model of the SIMMER code with the discrete element method (DEM) for the solid phase to reasonably simulate the particle behaviors as well as the fluid-particle interactions in multi-phase flows. In this study, in order to validate the multi-fluid model of the SIMMER code coupled with DEM, numerical simulations were performed on a series of self-leveling experiments using a gas injection method in cylindrical particle beds. The effects of friction coefficient on the simulation results were investigated by sensitivity analysis. Though more extensive validations are needed, the reasonable agreement between simulation results and corresponding experimental data preliminarily demonstrates the potential ability of the present method in simulating the self-leveling behaviors of debris bed. It is expected that the SIMMER code coupled with DEM is a prospective computational tool for analysis of safety issues related to solid particle debris bed in SFRs.

Journal Articles

Multi-threading performance of Geant4, MCNP6, and PHITS Monte Carlo codes for tetrahedral-mesh geometry

Han, M. C.*; Yeom, Y. S.*; Lee, H. S.*; Shin, B.*; Kim, C. H.*; Furuta, Takuya

Physics in Medicine and Biology, 63(9), p.09NT02_1 - 09NT02_9, 2018/05

 Times Cited Count:2 Percentile:78.68(Engineering, Biomedical)

The multi-threading computation performances of the Geant4, MCNP6, and PHITS codes were evaluated using three tetrahedral-mesh phantoms with different complexity. Photon and neutron transport simulations were conducted and the initialization time, calculation time, and memory usage were measured as a function of the number of threads N used in the simulation. The initialization time significantly increases with the complexity of the phantom, but not much with the number of the threads. For the calculation time, Geant4 showed good parallelization efficiency with multi-thread computation (30 times speed-up factor for N = 40) adopting the private tallies while saturation of the speed-up factor were observed in MCNP6 and PHITS (10 and a few times for N = 40) due to the time delay for the sharing tallies. On the other hand, Geant4 requires larger memory specification and the memory usage rapidly increases with the number of threads compared to MCNP6 or PHITS. It is notable that when compared to the other codes, the memory usage of PHITS is much smaller, regardless of both the complexity of the phantom and the number of the threads.

Journal Articles

Molybdenum adsorption properties of alumina-embedded mesoporous silica for medical radioisotope production

Saptiama, I.*; Kaneti, Y. V.*; Oveisi, H.*; Suzuki, Yoshitaka; Tsuchiya, Kunihiko; Takai, Kimiko*; Sakae, Takeji*; Pradhan, S.*; Hossain, M. S. A.*; Fukumitsu, Nobuyoshi*; et al.

Bulletin of the Chemical Society of Japan, 91(2), p.195 - 200, 2018/02

 Times Cited Count:28 Percentile:6.78(Chemistry, Multidisciplinary)

no abstracts in English

Journal Articles

Overall approaches and experiences of first-time participants in the Nuclear Forensics International Technical Working Group's Fourth Collaborative Material Exercise (CMX-4)

Ho, D. M. L.*; Nelwamondo, A. N.*; Okubo, Ayako; Rameb$"a$ck, H.*; Song, K.*; Han, S.-H.*; Hancke, J. J.*; Holmgren, S.*; Jonsson. S.*; Kataoka, Osamu; et al.

Journal of Radioanalytical and Nuclear Chemistry, 315(2), p.353 - 363, 2018/02

 Times Cited Count:0 Percentile:100(Chemistry, Analytical)

The Fourth Collaborative Material Exercise (CMX-4) of the Nuclear Forensics International Technical Working Group (ITWG) registered the largest participation for this exercise in nuclear forensics, with seven of the 17 laboratories participating for the first time. In this paper, participants from five of the first-time laboratories shared their individual experience in this exercise, from preparation to analysis of samples. The exercise proved to be highly useful for testing procedures, repurposing established methods, exercising skills, and improving the understanding of nuclear forensic signatures and their interpretation trough the post-exercise review meeting.

Journal Articles

The Application of radiochronometry during the 4th collaborative materials exercise of the nuclear forensics international technical working group (ITWG)

Kristo, M. J.*; Williams, R.*; Gaffney, A. M.*; Kayzar-Boggs, T. M.*; Schorzman, K. C.*; Lagerkvist, P.*; Vesterlund, A.*; Rameb$"a$ck, H.*; Nelwamondo, A. N.*; Kotze, D.*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 315(2), p.425 - 434, 2018/02

 Times Cited Count:2 Percentile:48.87(Chemistry, Analytical)

In a recent international exercise, 10 international nuclear forensics laboratories successfully performed radiochronometry on three low enriched uranium oxide samples, providing 12 analytical results using three different parent-daughter pairs serving as independent chronometers. The vast majority of the results were consistent with one another and consistent with the known processing history of the materials. In general, for these particular samples, mass spectrometry gave more accurate and more precise analytical results than decay counting measurements. In addition, the concordance of the $$^{235}$$U-$$^{231}$$Pa and $$^{234}$$U-$$^{230}$$Th chronometers confirmed the validity of the age dating assumptions, increasing confidence in the resulting conclusions.

Journal Articles

The $$^{95}$$Zr($$n, gamma$$)$$^{96}$$Zr cross section from the surrogate ratio method and its effect on $$s$$-process nucleosynthesis

Yan, S. Q.*; Li, Z. H.*; Wang, Y. B.*; Nishio, Katsuhisa; Lugaro, M.*; Karakas, A. I.*; Makii, Hiroyuki; Mohr, P.*; Su, J.*; Li, Y. J.*; et al.

Astrophysical Journal, 848(2), p.98_1 - 98_8, 2017/10

 Times Cited Count:0 Percentile:100(Astronomy & Astrophysics)

Journal Articles

Implementation of tetrahedral-mesh geometry in Monte Carlo radiation transport code PHITS

Furuta, Takuya; Sato, Tatsuhiko; Han, M. C.*; Yeom, Y. S.*; Kim, C. H.*; Brown, J. L.*; Bolch, W. E.*

Physics in Medicine and Biology, 62(12), p.4798 - 4810, 2017/06

 Times Cited Count:6 Percentile:40.64(Engineering, Biomedical)

A new function to treat tetrahedral-mesh geometry, a type of polygon-mesh geometry, was implemented in the Particle and Heavy Ion Transport code Systems (PHITS). Tetrahedral-mesh is suitable to describe complex geometry including curving shapes. In addition, construction of three-dimensional geometry using CAD software becomes possible with file format conversion. We have introduced a function to create decomposition maps of tetrahedral-mesh objects at the initial process so that the computational time for transport process can be reduced. Owing to this function, transport calculation in tetrahedral-mesh geometry can be as fast as that for the geometry in voxel-mesh with the same number of meshes. Due to adaptability of tetrahedrons in size and shape, dosimetrically equivalent objects can be represented by tetrahedrons with much fewer number of meshes compared with the voxels. For dosimetric calculation using computational human phantom, significant acceleration of the computational speed, about 4 times, was confirmed by adopting the tetrahedral mesh instead of the voxel.

Journal Articles

Examination of the surrogate ratio method for the determination of the $$^{93}$$Zr(n,$$gamma$$)$$^{94}$$Zr cross section with $$^{90,92}$$Zr($$^{18}$$O,$$^{16}$$O)$$^{92,94}$$Zr reactions

Yan, S. Q.*; Li, Z. H.*; Wang, Y. B.*; Nishio, Katsuhisa; Makii, Hiroyuki; Su, J.*; Li, Y. J.*; Nishinaka, Ichiro; Hirose, Kentaro; Han, Y. L.*; et al.

Physical Review C, 94(1), p.015804_1 - 015804_5, 2016/07

 Times Cited Count:3 Percentile:61.34(Physics, Nuclear)

Journal Articles

Development of a prototype GEM TPC with a gating grid for an H-dibaryon search experiment at J-PARC

Sako, Hiroyuki; Sugimura, Hitoshi; Ahn, J. K.*; Han, Y.*; Hasegawa, Shoichi; Hwang, S. H.*; Ichikawa, Yudai; Imai, Kenichi; Kiuchi, Ryuta*; Ozawa, Kyoichiro; et al.

Nuclear Instruments and Methods in Physics Research A, 763, p.65 - 81, 2014/11

 Times Cited Count:4 Percentile:57.92(Instruments & Instrumentation)

We developed a prototype TPC for an H-dibaryon search experiment at J-PARC. To investigate its performance, we conducted tests with Ar-CH$$_{4}$$ (90:10) and Ar-CF$$_{4}$$ (95:5), where the former is mainly used. The detection efficiency was measured to be 98% at the beam rate up to $$5times10^{5}$$ cps/cm$$^{2}$$, and 90% at the rate of $$3times10^{6}$$ cps/cm$$^{2}$$. Based on the measured horizontal resolution of 0.19-0.46 mm at the drift length of 5-20 cm, the position resolution of better than 0.3 mm is estimated in 1 T magnetic field. The ion backflow fraction was measured to be 5% and reduced up to 3% at the gain of $$1.6times10^{4}$$. The horizontal position distortion due to ion backflow in the gate operation was suppressed within $$pm 0.2$$ mm at the beam rates up to $$5times10^{5}$$ cps/cm$$^{2}$$. On the other hand, the distortion with the gate open was measured to be $$pm2$$ mm. The distortion in the final experiment is estimated to be $$0.3 pm 0.2$$ mm.

Journal Articles

Development of high voltage power supply for the KSTAR 170 GHz ECH and CD system

Jeong, J. H.*; Bae, Y. S.*; Joung, M.*; Kim, H. J.*; Park, S. I.*; Han, W. S.*; Kim, J. S.*; Yang, H. L.*; Kwak, J. G.*; Sakamoto, Keishi; et al.

Fusion Engineering and Design, 88(5), p.380 - 387, 2013/06

 Times Cited Count:1 Percentile:86.35(Nuclear Science & Technology)

Journal Articles

Anisotropic two-dimensional electron gas at the LaAlO$$_{3}$$/SrTiO$$_{3}$$ (110) interface

Annadi, A.*; Zhang, Q.*; Renshaw Wang, X.*; Tuzla, N.*; Gopinadhan, K.*; L$"u$, W. M.*; Roy Barman, A.*; Liu, Z. Q.*; Srivastava, A.*; Saha, S.*; et al.

Nature Communications (Internet), 4, p.1838_1 - 1838_7, 2013/05

 Times Cited Count:80 Percentile:4.19(Multidisciplinary Sciences)

Journal Articles

ITER magnet systems; From qualification to full scale construction

Nakajima, Hideo; Hemmi, Tsutomu; Iguchi, Masahide; Nabara, Yoshihiro; Matsui, Kunihiro; Chida, Yutaka; Kajitani, Hideki; Takano, Katsutoshi; Isono, Takaaki; Koizumi, Norikiyo; et al.

Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03

The ITER organization and 6 Domestic Agencies (DA) have been implementing the construction of ITER superconducting magnet systems. Four DAs have already started full scale construction of Toroidal Field (TF) coil conductors. The qualification of the radial plate manufacture has been completed, and JA and EU are ready for full scale construction. JA has qualified full manufacturing processes of the winding pack with a 1/3 prototype and made 2 full scale mock-ups of the basic segments of TF coil structure to optimize and industrialize the manufacturing process. Preparation and qualification of the full scale construction of the TF coil winding is underway by EU. Procurement of the manufacturing equipment is near completion and qualification of manufacturing processes has already started. The constructions of other components of the ITER magnet systems are also going well towards the main goal of the first plasma in 2020.

Journal Articles

ENDF/B-VII.1 nuclear data for science and technology; Cross sections, covariances, fission product yields and decay data

Chadwick, M. B.*; Herman, M.*; Oblo$v{z}$insk$'y$, P.*; Dunn, M. E.*; Danon, Y.*; Kahler, A. C.*; Smith, D. L.*; Pritychenko, B.*; Arbanas, G.*; Arcilla, R.*; et al.

Nuclear Data Sheets, 112(12), p.2887 - 2996, 2011/12

 Times Cited Count:1374 Percentile:0.01(Physics, Nuclear)

The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. It features extension of covered nuclei, covariance data for 190 nuclei, R-matrix analyses of neutron reactions on light nuclei, updates for some medium-heavy and actinoid nuclei, etc. Criticality benchmark tests with a transport simulation code MCNP shows improved performances.

Journal Articles

Event structure and double helicity asymmetry in jet production from polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07

 Times Cited Count:22 Percentile:28.37(Astronomy & Astrophysics)

We report on the event structure and double helicity asymmetry ($$A_{LL}$$) of jet production in longitudinally polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV. Photons and charged particles were measured by the PHENIX experiment. Event structure was compared with the results from PYTHIA event generator. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order perturbative QCD calculation. We measured $$A_{LL}$$ = -0.0014 $$pm$$ 0.0037 at the lowest $$P_T$$ bin and -0.0181 $$pm$$ 0.0282 at the highest $$P_T$$ bin. The measured $$A_{LL}$$ is compared with the predictions that assume various $$Delta G(x)$$ distributions.

Journal Articles

Identified charged hadron production in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

 Times Cited Count:134 Percentile:0.69(Physics, Nuclear)

Transverse momentum distributions and yields for $$pi^{pm}, K^{pm}, p$$, and $$bar{p}$$ in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different $$sqrt{s}$$ collisions. We also present the scaling properties such as $$m_T$$ and $$x_T$$ scaling and discuss the mechanism of the particle production in $$p + p$$ collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

58 (Records 1-20 displayed on this page)