A One-third magnetization plateau phase as evidence for the Kitaev interaction in a honeycomb-lattice antiferromagnet

Shangguan, Y.*; Bao, S.*; Dong, Z.-Y.*; Xi, N.*; Gao, Y.-P.*; Ma, Z.*; Wang, W.*; Qi, Z.*; Zhang, S.*; Huang, Z.*; et al.

Nature Physics, 19(12), p.1883 - 1889, 2023/09

https://doi.org/10.1038/s41567-023-02212-2

Status of the uncertainty quantification for severe accident sequences of different NPP-designs in the frame of the H-2020 project MUSA

Brumm, S.*; Gabrielli, F.*; Sanchez-Espinoza, V.*; Groudev, P.*; Ou, P.*; Zhang, W.*; Malkhasyan, A.*; Bocanegra, R.*; Herranz, L. E.*; Berda, M.*; et al.

Proceedings of 10th European Review Meeting on Severe Accident Research (ERMSAR 2022) (Internet), 13 Pages, 2022/05

Asymmetric and symmetric fission of excited nuclei of Hg and Pb formed in the reactions with Ar and Ca ions

Bogachev, A. A.*; Kozulin, E. M.*; Knyazheva, G. N.*; Itkis, I. M.*; Itkis, M. G.*; Novikov, K. V.*; Kumar, D.*; Banerjee, T.*; Diatlov, I. N.*; Cheralu, M.*; et al.

Physical Review C, 104(2), p.024623_1 - 024623_11, 2021/08

https://doi.org/10.1103/PhysRevC.104.024623

For the purpose of the study of asymmetric and symmetric fission modes of Hg and Pb nuclei, mass-energy distributions of fission fragments of Hg and Pb formed in the Ar + Sm and Ca + Sm reactions, respectively, at energies near the Coulomb barrier have been measured using the double-arm time-of-flight spectrometer CORSET and compared with previously measured Pb isotopes produced in the Ca + Sm reactions. Conclusion is the studied properties of asymmetric fission of Hg and Pb nuclei point out the existence of well deformed proton shell at Z36 and less deformed proton shell at Z46.

In situ observations reveal how spectral reflectance responds to growing season phenology of an open evergreen forest in Alaska

Kobayashi, Hideki*; Nagai, Shin*; Kim, Y.*; Yan, W.*; Ikeda, Kyoko*; Ikawa, Hiroki*; Nagano, Hirohiko; Suzuki, Rikie*

Remote Sensing, 10(7), p.1071_1 - 1071_19, 2018/07

https://doi.org/10.3390/rs10071071

Plant phenology timings, such as spring green-up and autumn senescence, are essential state information characterizing biological responses and terrestrial carbon cycles. Current efforts for the in situ reflectance measurements are not enough to obtain the exact interpretation of how seasonal spectral signature responds to phenological stages in boreal evergreen needleleaf forests. This study shows the first in situ continuous measurements of canopy scale (overstory + understory) and understory spectral reflectance and vegetation index in an open boreal forest in interior Alaska. Two visible and near infrared spectroradiometer systems were installed at the top of the observation tower and the forest understory, and spectral reflectance measurements were performed in 10 min intervals from early spring to late autumn. We found that canopy scale normalized difference vegetation index (NDVI) varied with the solar zenith angle. On the other hand, NDVI of understory plants was less sensitive to the solar zenith angle. Due to the influence of the solar geometry, the annual maximum canopy NDVI observed in the morning satellite overpass time (10-11 am) shifted to the spring direction compared with the standardized NDVI by the fixed solar zenith angle range (60-70 degree). We also found that the in situ NDVI time-series had a month-long high NDVI plateau in autumn, which was completely out of photosynthetically active periods when compared with eddy covariance net ecosystem exchange measurements. The result suggests that the onset of an autumn high NDVI plateau is likely to be the end of the growing season. In this way, our spectral measurements can serve as baseline information for the development and validation of satellite-based phenology algorithms in the northern high latitudes.

Examination of the surrogate ratio method for the determination of the Zr(n,)Zr cross section with Zr(O,O)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

https://doi.org/10.1103/PhysRevC.94.015804

Local thermal expansion and the C-C stretch vibration of the dicarbon antisite in 4H SiC

Devaty, R. P.*; Yan, F.*; Choyke, W. J.*; Gali, A.*; Kimoto, Tsunenobu*; Oshima, Takeshi

Materials Science Forum, 717-720, p.263 - 266, 2012/05

https://doi.org/10.4028/www.scientific.net/MSF.717-720.263

On maximizing the ICRF antenna loading for ITER plasmas

Mayoral, M.-L.*; Bobkov, V.*; Colas, L.*; Goniche, M.*; Hosea, J.*; Kwak, J. G.*; Pinsker, R.*; Moriyama, Shinichi; Wukitch, S.*; Baity, F. W.*; et al.

Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 11 Pages, 2011/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2010/html/node54.htm#14192

For any given ICRF antenna design for ITER, the maximum achievable power strongly depends on the density profiles in the SOL. It has been suggested that gas injection can be used to modify the SOL profiles and thus minimize the sensitivity of the ICRF coupling to variations in the density at the edge of the confined plasma. Recently joint experiments coordinated by the ITPA were performed to characterize further this method. An increase in SOL density during gas injection led to improved coupling for all tokamaks in this multi-machine comparison. The effectiveness of using gas injection over a wide range of conditions, as a tool to tailor the edge density in front of the ICRF antennas, is documented for different gas inlet location and plasma configurations. In addition, any deleterious effects on the confinement and interaction with the antenna near-field are not investigated.

Tomography of an ultrafast laser driven proton source

Ter-Avetisyan, S.*; Schnrer, M.*; Nickles, P. V.*; Sandner, W.*; Borghesi, M.*; Nakamura, Tatsufumi; Mima, Kunioki*

Physics of Plasmas, 17(6), p.063101_1 - 063101_6, 2010/06

https://doi.org/10.1063/1.3428740

Using a multichannel Thomson spectrometer we have implemented a tomographic approach allowing the reconstruction of the emission characteristics of a laser driven proton source with high energy and spatial resolution. The results demonstrate the complexity of the temporal and spatial characteristics of such a source. The emitted proton beam, which is laminar and divergent ant high energies, becomes convergent at low energies. This implies that a fraction of the proton beam having this kinetic energy is emitted in a collimated way from the target at the turning point between these tow behaviors. Only a finite fraction of the target surface is contributing to the ion spectrum, which is measured at a specific angle within the beam cone. Therefore the momentum distribution of the protons in the emitted beam at any point in space can be controlled by determining the proton source area.

Thermal histories of defect centers as measured by low temperature photoluminescence in n- and p-type 4H SiC epilayers generated by irradiation with 170 KeV or 1 MeV electrons

Yan, F.*; Devaty, R. P.*; Choyke, W. J.*; Danno, Katsunori*; Alfieri, G.*; Kimoto, Tsunenobu*; Onoda, Shinobu; Oshima, Takeshi; Reshanov, S. A.*; Beljakowa, S.*; et al.

Materials Science Forum, 645-648, p.419 - 422, 2010/00

Defects in n- and p-type 4H-SiC epitaxial layer were investigated by low temperature photoluminescence spectroscopy (LTPL) and deep level transient spectroscopy (DLTS). Defects were introduced by either 170 keV or 1 MeV electron irradiation into samples at RT. The samples were annealed from 25C to 1700C in 100C steps. As a result of LTPL measurements, L line was observed after irradiation. In previous studies, L line is thought to correlate with Z/Z centers in DLTS measurements. However, in this study, no correlation between L and Z1/Z was observed.

New lines and issues associated with deep defect spectra in electron, proton and He ion irradiated 4H SiC

Yan, F.*; Devaty, R. P.*; Choyke, W. J.*; Kimoto, Tsunenobu*; Oshima, Takeshi; Pensl, G.*; Gali, A.*

Materials Science Forum, 645-648, p.411 - 414, 2010/00

Silicon Carbide (SiC) samples were irradiated with electron, proton and He ions and defects in the irradiated SiC were investigated by Low Temperature Photo Luminescence (LTPL). After irradiation, PL spectra between 2.48 and 2.62 eV were measured at 7 K. As a results, several PL lines were observed. These lines showed the same annealing behavior and were annealed out between 1300 and 1400C. Therefore, it is concluded that these line have the same origin. In addition, as a result of simulation, the structure of the defect is determined to be di-carbon antisite.