Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
magnetic orderings in a triangular lattice; Implications for multi- orderings in general two-dimensional latticesPark, P.*; Cho, W.*; Kim, C.*; An, Y.*; Iida, Kazuki*; Kajimoto, Ryoichi; Matin, S.*; Zhang, S.-S.*; Batista, C. D.*; Park, J.-G.*
Physical Review X, 15(3), p.031032_1 - 031032_29, 2025/07
Times Cited Count：5 Percentile：74.19(Physics, Multidisciplinary)
Bi
Park, P.*; Ortiz, B. R.*; Spargue, M.*; Sakuya, A. P.*; Chen, S. A.*; Frontzek, M. D.*; Tian, W.*; Sibille, R.*; Mazzone, D. G.*; Tabata, Chihiro; et al.
Nature Communications (Internet), 16, p.4384_1 - 4384_9, 2025/05
Times Cited Count：17 Percentile：97.29(Multidisciplinary Sciences)Taya, Hidetoshi*; Park, A.*; Cho, S.*; Gubler, P.; Hattori, Koichi*; Hong, J.*; Huang, X.-G.*; Lee, S. H.*; Monnai, Akihiko*; Onishi, Akira*; et al.
Physical Review C, 102(2), p.021901_1 - 021901_6, 2020/08
Times Cited Count：8 Percentile：54.27(Physics, Nuclear)Zhang, Y.*; Guo, H.*; Kim, S. B.*; Wu, Y.*; Ostojich, D.*; Park, S. H.*; Wang, X.*; Weng, Z.*; Li, R.*; Bandodkar, A. J.*; et al.
Lab on a Chip, 19(9), p.1545 - 1555, 2019/05
Times Cited Count：224 Percentile：99.73(Biochemical Research Methods)This paper introduces two important advances in recently reported classes of soft, skin-interfaced microfluidic systems for sweat capture and analysis: (1) a simple, broadly applicable means for collection of sweat that bypasses requirements for physical/mental exertion or pharmacological stimulation and (2) a set of enzymatic chemistries and colorimetric readout approaches for determining the concentrations of creatinine and urea in sweat, across physiologically relevant ranges. The results allow for routine, non-pharmacological capture of sweat across patient populations, such as infants and the elderly, that cannot be expected to sweat through exercise, and they create potential opportunities in the use of sweat for kidney disease screening/monitoring.
Oh, J.*; Le, M. D.*; Nahm, H.-H.*; Sim, H.*; Jeong, J.*; Perring, T. G.*; Woo, H.*; Nakajima, Kenji; Kawamura, Seiko; Yamani, Z.*; et al.
Nature Communications (Internet), 7, p.13146_1 - 13146_6, 2016/10
Times Cited Count：72 Percentile：87.53(Multidisciplinary Sciences)Magnons and phonons are fundamental quasiparticles in a solid and can be coupled together to form a hybrid quasi-particle. However, detailed experimental studies on the underlying Hamiltonian of this particle are rare for actual materials. Moreover, the anharmonicity of such magnetoelastic excitations remains largely unexplored, although it is essential for a proper understanding of their diverse thermodynamic behaviour and intrinsic zero-temperature decay. Here we show that in non-collinear antiferromagnets, a strong magnon phonon coupling can significantly enhance the anharmonicity, resulting in the creation of magnetoelastic excitations and their spontaneous decay. By measuring the spin waves over the full Brillouin zone and carrying out anharmonic spin wave calculations using a Hamiltonian with an explicit magnon phonon coupling, we have identified a hybrid magnetoelastic mode in (Y,Lu)MnO and quantified its decay rate and the exchange-striction coupling termrequired to produce it.
Sr
CuOPark, S. R.*; Fukuda, Tatsuo; Hamann, A.*; Lamago, D*; Pintschovius, L.*; Fujita, Masaki*; Yamada, Kazuyoshi*; Reznik, D.*
Physical Review B, 89(2), p.020506_1 - 020506_5, 2014/01
Times Cited Count：36 Percentile：76.69(Materials Science, Multidisciplinary)Luce, T. C.*; Challis, C. D.*; Ide, Shunsuke; Joffrin, E.*; Kamada, Yutaka; Politzer, P. A.*; Schweinzer, J.*; Sips, A. C. C.*; Stober, J.*; Giruzzi, G.*; et al.
Nuclear Fusion, 54(1), p.013015_1 - 013015_15, 2013/12
Times Cited Count：55 Percentile：89.66(Physics, Fluids & Plasmas)Pace, D. C.*; Austin, M. E.*; Bass, E. M.*; Budny, R.*; Heidbrink, W. W.*; Hillesheim, J. C.*; Holcomb, C. T.*; Gorelenkova, M.*; Grierson, B. A.*; McCune, D. C.*; et al.
Physics of Plasmas, 20(5), p.056108_1 - 056108_18, 2013/05
Times Cited Count：35 Percentile：79.15(Physics, Fluids & Plasmas)Energetic ion transport due to microturbulence is investigated in MHD-quiescent plasmas by way of neutral beam injection in the DIII-D tokamak. A range of on-axis and off-axis beam injection scenarios are employed to vary relevant parameters such as the character of the background microturbulence and the value of Eb/Te, where Eb is the energetic ion energy and Te the electron temperature. In all cases it is found that any transport enhancement due to microturbulence is too small to observe experimentally. These transport effects are modeled using numerical and analytic expectations that calculate the energetic ion diffusivity due to microturbulence. It is determined that energetic ion transport due to coherent modes, including possible reductions in neutral beam current drive, is a considerably larger effect and should therefore be considered more important for ITER.
Sato, Hiroyuki; Park, H.*; Knoll, D.*
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 10 Pages, 2011/10
Multiphysics core simulations for a prismatic-type VHTR are performed in this study. Our solution scheme is based on the JFNK method. As a preliminary example, a thermal-fluid calculation is performed with an idealized two-dimensional symmetric representation of the GT-MHR and compared with the RELAP5-3D simulation results. Also, a neutronics calculation is conducted using the same geometry as the thermal-fluid calculation, and using cross section data obtained from an HTGR benchmark problem. In addition, a coupled steady-state thermal-fluids neutronics calculation is performed. The calculation results showed that the developed prismatic VHTR core simulator can perform tightly-coupled multiphysics simulations efficiently.
Suzuki, Takahiro; Akers, R.*; Gates, D. A.*; G
nter, S.*; Heidbrink, W. W.*; Hobirk, J.*; Luce, T. C.*; Murakami, Masanori*; Park, J. M.*; Turnyanskiy, M.*; et al.
Nuclear Fusion, 51(8), p.083020_1 - 083020_8, 2011/08
Times Cited Count：19 Percentile：58.62(Physics, Fluids & Plasmas)Joint experiments investigating the off-axis neutral beam current drive (NBCD) capability to be utilized for advanced operation scenario development in ITER was conducted in 5 tokamaks (AUG, DIII-D, JT-60U, MAST and NSTX) through the ITPA. We discuss results obtained in the joint experiments, where the toroidal field, 
, covered 0.3-3.7 T, the plasma current, 
, 0.6-1.2 MA, and the beam energy, Eb, 67-350 keV. A current profile broadened by off-axis NBCD was observed in MAST. In DIII-D, good agreement between the measured and calculated NB driven current profile was observed. In JT-60U, agreement between measured and calculated NBCD location was obtained, when the NBCD location (0.3-0.6 in 
/
), heating power (6-13 MW), triangularity 
(0.25-0.45), and 
(85 and 350 keV) were widely scanned. In AUG (at low 
0.2) and DIII-D, introduction of a fast ion diffusion coefficient of 
0.3-0.5 m
/s in the calculation gave better agreement at high heating power (5 and 7.2 MW), suggesting anomalous transport of fast ions by turbulence. It was found through these ITPA joint experiments that NBCD related physics quantities reasonably agree with calculations (with = 0-0.5 m/s) in all devices when there is no MHD activity except ELMs. Proximity of measured off-axis beam driven current to the corresponding calculation with = 0 has been discussed for ITER in terms of a theoretically predicted scaling of fast-ion diffusion that depends on /
for electrostatic turbulence or 
for electromagnetic turbulence.
Suzuki, Takahiro; Akers, R.*; Gates, D. A.*; Gnter, S.*; Heidbrink, W. W.*; Hobirk, J.*; Luce, T. C.*; Murakami, Masanori*; Park, J. M.*; Turnyanskiy, M.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2010/10
Joint experiments investigating the off-axis neutral beam current drive (NBCD) capability to be utilized for advanced operation scenario development in ITER was conducted in 4 tokamaks (AUG, DIII-D, JT-60U and MAST) through the ITPA. We discuss results obtained in the joint experiments, where the toroidal field, Bt, covered 0.3-3.7 T, the plasma current, Ip, 0.6-1.2 MA, and the beam energy, Eb, 67-350 keV. A current profile broadened by off-axis NBCD was observed in MAST. In DIII-D, good agreement between the measured and calculated NB driven current profile was observed. In JT-60U, agreement between measured and calculated NBCD location was obtained, when the NBCD location (0.3-0.6 in r/a), heating power (6-13 MW), triangularity d (0.25-0.45), and Eb (85 and 350 keV) were widely scanned. In AUG (at low d 0.2) and DIII-D, introduction of a fast ion diffusion coefficient of Db 0.3-0.5 m/s in the calculation gave better agreement at high heating power (5 and 7.2 MW), suggesting anomalous transport of fast ions by turbulence. It was found through these ITPA joint experiments that NBCD related physics quantities reasonably agree with calculations (with Db=0-0.5 m/s) in all devices when there is no MHD activity except ELMs.
Park, J. M.*; Murakami, Masanori*; Petty, C. C.*; Heidbrink, W. W.*; Osborne, T. H.*; Holcomb, C. T.*; Van Zeeland, M. A.*; Prater, R.*; Luce, T. C.*; Wade, M. R.*; et al.
Physics of Plasmas, 16(9), p.092508_1 - 092508_10, 2009/09
Times Cited Count：26 Percentile：65.60(Physics, Fluids & Plasmas)Neutral beam current drive (NBCD) experiments in DIII-D using vertically shifted plasmas to move the current drive away from the axis have clearly demonstrated robust off-axis NBCD. Time-dependent measurements of magnetic pitch angles by the motional Stark effect diagnostic are used to obtain the evolution of the poloidal magnetic flux, which indicates a broad off-axis NBCD profile with a peak at about half the plasma radius. In most cases, the measured off-axis NBCD profile is consistent with calculations using an orbit-following Monte-Carlo code for the beam ion slowing down including finite-orbit effects, provided there is no large-scale MHD activity such as Alfv
n eigenmodes modes or sawteeth. Good agreement is found between the measured pitch angles and those from simulations using transport-equilibrium codes. Two-dimensional image of Doppler-shifted fast ion D
light emitted by neutralized energetic ions shows clear evidence for a hollow profile of beam ion density, consistent with classical beam ion slowing down. The magnitude of off-axis NBCD is sensitive to the alignment of the beam injection relative to the helical pitch of the magnetic field lines. If the signs of B and I yield the proper helicity, both measurement and calculation indicate that the efficiency is as good as on-axis NBCD because the increased fraction of trapped electrons reduces the electron shielding of the injected ion current, in contrast with electron current drive schemes where the trapping of electrons degrades the efficiency. The measured off-axis NBCD increases approximately linearly with the injection power, although a modest amount of fast ion diffusion is needed to explain an observed difference in the NBCD profile between the measurement and the calculation at high injection power.
Murakami, Masanori*; Park, J. M.*; Petty, C. C.*; Luce, T. C.*; Heidbrink, W. W.*; Osborne, T. H.*; Prater, R.*; Wade, M. R.*; Anderson, P. M.*; Austin, M. E.*; et al.
Nuclear Fusion, 49(6), p.065031_1 - 065031_8, 2009/06
Times Cited Count：47 Percentile：82.29(Physics, Fluids & Plasmas)Modification of the two existing DIII-D neutral beam lines is planned to allow vertical steering to provide off-axis neutral beam current drive (NBCD) peaked as far off-axis as half the plasma minor radius. New calculations for a downward-steered beam indicate strong current drive with good localization off-axis so long as the toroidal magnetic field, BT, and the plasma current, Ip, point in the same direction. This is due to good alignment of neutral beam injection (NBI) with the local pitch of the magnetic field lines. This model has been tested experimentally on DIII-D by an injecting equatorially-mounted NBs into reduced size plasmas that are vertically displaced with respect to the vessel midplane. The existence of off-axis NBCD is evident in the changes seen in sawtooth behavior in the internal inductance. By shifting the plasma upward or downward, or by changing the sign of the toroidal field, measured off-axis NBCD profiles measured with motional Stark effect data and internal loop voltage show a difference in amplitude (40%-45%) consistent with predicted differences predicted by the changed NBI alignment with respect to the helicity of the magnetic field lines. The effects of NB injection direction relative to field line helicity can be large even in ITER: off-axis NBCD can be increased by more than 20% if the BT direction is reversed. Modification of the DIII-D NB system will strongly support scenario development for ITER and future tokamaks as well as providing flexible scientific tools for understanding transport, energetic particles and heating and current drive.
PRonning, F.*; Bauer, E. D.*; Park, T.*; Baek, S.-H.*; Sakai, Hironori; Thompson, J. D.*
Physical Review B, 79(13), p.134507_1 - 134507_7, 2009/04
Times Cited Count：78 Percentile：90.13(Materials Science, Multidisciplinary)BiPark, P.*; Ortiz, B. R.*; Spargue, M.*; Sakuya, A. P.*; Chen, S. A.*; Frontzek, M. D.*; Tian, W.*; Sibille, R.*; Mazzone, D. G.*; Tabata, Chihiro; et al.
no journal, ,
V nuclear magnetic resonance study of the triangular Kondo lattice system YbV
SnSakai, Hironori; Park, S.*; Dioguardi, A. P.*; Furukawa, Tetsuya*; Sasaki, Takahiko*; Kimata, Motoi; Kambe, Shinsaku; Tokunaga, Yo; Thomas, S. M.*; Thompson, J. D.*; et al.
no journal, ,
YbVSn has a HfFeGe-type structure, in which V atoms form a Kagome lattice and Yb atoms form a triangular lattice. This rare Yb-based Kondo triangular lattice system has attracted much attention as an essential model to explore the relationship between quantum magnetism and topological properties. To microscopically clarify the quantum criticality of this system, we have performed V nuclear magnetic resonance (NMR) studies using a single crystal of YbVSn. In this talk, I will report on the spectral assignments of V nuclei revealed from V NMR measurements in the paramagnetic state.
Kikuchi, Kenji; Yong, D.*; Al Mazouzi, A.*; Jean, H.*; Maloy, S. A.*; Lindau, R.*; Park, J. Y.*; Gr
schel, F.*
no journal, ,
MEGAPIE (Megawatt Pilot Experiment) was successfully done in 2006. Components performance during high-energy proton beam bombardment under the liquid lead-bismuth flow will be studied to define ADS quality condition. Samples are cut from the spent target and distributed to collaborated organizations. PIE (Post Irradiation Experiment) will provide knowledge on materials quality evaluated by design, construction and operation. It is scheduled to pre-test in 2008-2009 and to do PIE in 2010 and 2011. Before conducting PIE round robin test is to be done in order to secure experiment technology level.
Suzuki, Takahiro; Akers, R.*; Gates, D. A.*; Gnter, S.*; Heidbrink, W. W.*; Hobirk, J.*; Luce, T. C.*; Murakami, Masanori*; Park, J. M.*; Turnyanskiy, M.*; et al.
no journal, ,
Joint experiments investigating the off-axis neutral beam current drive (NBCD) capability to be utilized for advanced operation scenario development in ITER was conducted in 5 tokamaks (AUG, DIII-D, JT-60U, MAST and NSTX) through the ITPA. We discuss results obtained in the joint experiments, where the toroidal field, Bt, covered 0.3-3.7 T, the plasma current, Ip, 0.6-1.2 MA, and the beam energy, Eb, 67-350 keV. A current profile broadened by off-axis NBCD was observed in MAST. In DIII-D, good agreement between the measured and calculated NB driven current profile was observed. In JT-60U, agreement between measured and calculated NBCD location was obtained, when the NBCD location (0.3-0.6 in r/a), heating power (6-13 MW), triangularity d (0.25-0.45), and Eb (85 and 350 keV) were widely scanned. In AUG (at low d 0.2) and DIII-D, introduction of a fast ion diffusion coefficient of Db 0.3-0.5 m/s in the calculation gave better agreement at high heating power (5 and 7.2 MW), suggesting anomalous transport of fast ions by turbulence. It was found through these ITPA joint experiments that NBCD related physics quantities reasonably agree with calculations (with Db=0-0.5 m/s) in all devices when there is no MHD activity except ELMs.
