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) reaction at 12, 20, and 30 MeVPatwary, M. K. A*; Kin, Tadahiro*; Aoki, Katsumi*; Yoshinami, Kosuke*; Yamaguchi, Masaya*; Watanabe, Yukinobu*; Tsukada, Kazuaki; Sato, Nozomi*; Asai, Masato; Sato, Tetsuya; et al.
Journal of Nuclear Science and Technology, 58(2), p.252 - 258, 2021/02
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)While designing deuteron accelerator neutron sources for radioisotopes production, nuclear data for light elements such as Li, Be, and C have been systematically measured in the deuteron energy range from a few MeV to around 50 MeV. Currently, the experimental data available on double-differential thick-target neutron yields (DDTTNYs) is insufficient, especially for deuteron energies between 18 and 33 MeV. In this study, we measured the DDTTNYs of () reactions on 
C target for incident deuteron energies of 12, 20, and 30 MeV using the multiple-foils activation method to improve nuclear data insufficiency. We applied the GRAVEL code for the unfolding process to derive the DDTTNYs. The results were compared with the calculation by DEURACS. The present data were also used to confirm the systematics of the differential neutron yields at 0
and total neutron yield per incident deuteron in the wide range of deuteron energy.
Kuroda, Kenta*; Ochi, Masayuki*; Suzuki, Hiroyuki*; Hirayama, Motoaki*; Nakayama, Mitsuhiro*; Noguchi, Ryo*; Bareille, C.*; Akebi, Shuntaro*; Kunisada, So*; Muro, Takayuki*; et al.
Physical Review Letters, 120(8), p.086402_1 - 086402_6, 2018/02
Times Cited Count：50 Percentile：91.74(Physics, Multidisciplinary)Nakayama, Hiromasa; Jurcakova, K.*; Nagai, Haruyasu
Journal of Nuclear Science and Technology, 50(5), p.503 - 519, 2013/05
Times Cited Count：15 Percentile：74.2(Nuclear Science & Technology)There is a potential problem that hazardous materials are accidentally or intentionally released within populated urban areas. In this study, we perform LESs of plume dispersion in idealized urban canopies where the surface geometries are represented by regularly arrayed obstacle arrays with various obstacle densities. In this paper, we examine the basic performance of the LES model by comparing to wind tunnel experiments.
Nakayama, Hiromasa; Jurcakova, K.*; Nagai, Haruyasu
Advances in Science & Research (Internet), 10, p.33 - 41, 2013/02
Times Cited Count：11 Percentile：98.34(Multidisciplinary Sciences)There is a potential problem that hazardous and flammable materials are accidentally or intentionally released within urban areas. Our objective is to compare our LES results for distribution patterns of mean and fluctuating concentrations in various actual urban areas with the existing LES and experimental results for those in regularly arrayed obstacles, and investigate the influence of actual urban surface geometries on the characteristics of mean and fluctuating concentrations.
Nakayama, Hiromasa; Jurcakova, K.*; Nagai, Haruyasu
Proceedings of International Workshop on Physical Modelling of Flow and Dispersion Phenomena (PHYSMOD 2011) (CD-ROM), 8 Pages, 2011/08
There is a potential problem that hazardous materials are intentionally released within populated urban areas. In this study, we perform Large-Eddy Simulation (LES) of plume dispersion within regular arrays of cubic buildings with various obstacle densities and investigate the influence of the building arrangement on the characteristics of mean and fluctuating concentrations. First, comparing with the experiments of approach flow, the turbulence characteristics of LES approach flow are found to be similar to those of the experiment. From this result, LES approach flow corresponding to a neutral atmospheric boundary layer is considered to be obtained. Next, comparing with the experimental results of concentrations in each case, the spanwise profiles of mean and r.m.s. concentrations are generally similar in the magnitude to the experimental data. Therefore, it is considered that our LES model for plume dispersion within various obstacle arrays gives satisfactory results.
Nakayama, Hiromasa; Jurcakova, K.*; Nagai, Haruyasu
Advances in Science & Research (Internet), 6, p.79 - 86, 2011/04
Times Cited Count：0 Percentile：1.11(Multidisciplinary Sciences)In this study, the cubic building arrays with roughness density of 0.16, 0.25 and 0.33 are set up. These surface geometries consist of 20
6, 257 and 289 arrays in streamwise and spanwise directions, respectively. Three cases of plume source located at the ground surface behind the building in the 6th, 7th and 8th row of the building array are tested. As a result, we can capture the dispersion process of a plume and the spatial distribution of mean and fluctuating concentrations depending on roughness density.
Tonomura, A.*; Hasai, H.*; Kamimura, O.*; Matsuda, T.*; Harada, K.*; Nakayama, Y.*; Shimoyama, J.*; Kishio, K.*; Hanaguri, T.*; Kitazawa, K.*; et al.
Nature, 412(6847), p.620 - 622, 2001/08
Times Cited Count：104 Percentile：94.31(Multidisciplinary Sciences)Direct observation microscopically elucidated the behaviour of vortices in Bi-2212 thin films. The isotropic pinning of vortices by columnar defects at low magnetic fields indirectly inferred by macroscopic magnetization measurements can be explained microscopically as follows; vortex lines are trapped along columns ate temperatures above 19K irrespective of the direction of the applied magnetic field; and at temperatures below 12K vortex lines always penetrate the film perpendicularly to the film plane owing to the increased background pinning compared to the columnar-defect pinning and also because of the demagnetization effect of thin film.
Nakayama, Takeshi*; Yamamoto, Masahiro; Abe, Mitsushi*; Shibata, Takatoshi; Otsuka, Michio*; Akiyama, Takashi*; Sato, K.*; Kikuchi, Kazuo; Wada, Y.*; Koike, Tsuneyuki; et al.
Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering (SOFE '99), p.227 - 230, 1999/10
no abstracts in English
Shimada, Taihei; Kabasawa, M.*; Nakayama, K.*; Hashimoto, H.*; Harami, Taikan; Suzuki, Hiromitsu
Proceedings of the 7th Symposium on Accelerator Science and Technology, p.305 - 308, 1989/00
The synchrotron and the beam transport lines have been designed. These are used as a part of the injection system for the 8 GeV storage ring of SPring-8. To keep high injection-efficiency into the storage ring, the emittance of the beam is designed to be smaller than 200 nm rad and transverse phase-space matching is made at the injection point of the ring. The calculation about the beam transport lines and the synchrotron is performed using the code SYNCH.
