Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Zhou, Z.*; Frost, W.*; Lloyd, D. C.*; 関 剛斎*; 窪田 崇秀*; Ramos, R.*; 齊藤 英治; 高梨 弘毅; 廣畑 貴文*
Journal of Magnetism and Magnetic Materials, 571, p.170575_1 - 170575_5, 2023/04
被引用回数：0 パーセンタイル：0(Materials Science, Multidisciplinary)Recent development in neuromorphic computation allows us to achieve low power and highly efficient calculations better than the conventional von Neumann computation. In order to achieve realistic synaptic operation, potentiation to add weighting to strengthen a selected artificial synapse. Such functionality can be achieved by reducing the electrical resistance of the artificial synapse. Recently, a ferromagnetic Heusler alloy used in a magnetoresistive junction has been demonstrated to crystallise via the layer-by-layer mode by introducing an electrical current pulse. In this study, we have extended the current-induced crystallisation to a junction with epitaxially-grown Heusler alloy after post-annealing for crystallisation. By combining this potentiation functionality with the neuromorphic operation, realistic synaptic computation can be developed.
Frost, W.*; 関 剛斎*; 窪田 崇秀*; Ramos, R.*; 齊藤 英治; 高梨 弘毅*; 廣畑 貴文*
Applied Physics Letters, 118(17), p.172405_1 - 172405_5, 2021/04
被引用回数：1 パーセンタイル：7.86(Physics, Applied)We demonstrate that the spin-Seebeck effect can be used to estimate the volume of edge domains formed in a giant magnetoresistive (GMR) device. The thermal gradient induced by Joule heating can be harnessed by the addition of a ferromagnetically insulating channel of Fe
O
on the sides of the GMR pillar. This generates a spin wave in FeO, which couples with the free-layer edge magnetization and controls the reversal of the ferromagnetic layers in one direction only, increasing the current density from 
A/cm
to 
A/cm. By simple assumption, we estimate the effect of the edge domain on magnetization reversal to be 
by spin-transfer torque.
-ray spectrum in 
U(
)牧井 宏之; 西尾 勝久; 廣瀬 健太郎; Orlandi, R.; L
guillon, R.; 小川 達彦; Soldner, T.*; K
ster, U.*; Pollitt, A.*; Hambsch, F.-J.*; et al.
Physical Review C, 100(4), p.044610_1 - 044610_7, 2019/10
被引用回数：11 パーセンタイル：74.44(Physics, Nuclear)The prompt fission -ray energy spectrum for cold-neutron induced fission of U was measured in the energy range 
= 0.8 - 20,MeV, by gaining a factor of about 10
in statistics compared to the measurements performed so far. The spectrum exhibits local bump structures at 
4,MeV and 
6,MeV, and also a broad one at 15,MeV. In order to understand the origins of these bumps, the -ray spectra were calculated using a statistical Hauser-Feshbach model, taking into account the de-excitation of all the possible primary fission fragments. It is shown that the bump at 4,MeV is created by the transitions between the discrete levels in the fragments around 
Sn, and the bump at 6,MeV mostly comes from the complementary light fragments. It is also indicated that a limited number of nuclides, which have high-spin states at low excitation energies, can contribute to the bump structure around 15,MeV, induced by the transition feeding into the low-lying high-spin states.
-ray emission in U ()牧井 宏之; 西尾 勝久; 廣瀬 健太郎; Orlandi, R.; Lguillon, R.*; 小川 達彦; Soldner, T.*; Kster, U.*; Hambsch, F.-J.*; 河野 俊彦*; et al.
no journal, ,
Prompt fission -ray spectra (PFGS) are important as they allow us to study the structure and de-excitation process of neutron-rich fission fragments. They are also required for the design of the Gen-IV fast reactors and advanced light-water reactors. For spontaneous fission of 
Cf, Cf(sf), prompt fission rays were observed up to energies of about 
20 MeV. For neutron-induced fissions, however, the measured PFGS are limited below 
= 9
10 MeV. In this work we extended the measurement of the PFGS for cold neutron-induced fission of U up to 
20 MeV by gaining a factor of about 10 in statistics compared to the measurements performed so far. The measurement was carried out at the PF1B cold-neutron facility of the ILL, Grenoble, France. The spectrum exhibits local bump structures at 4 MeV and 6 MeV and also a broad one at 15 MeV. In this contribution, we will discuss the origins of the bump structures in comparison with the statistical Hauser-Feshbach model calculation.
U(n
,f)における即発線スペクトルの測定牧井 宏之; 西尾 勝久; 廣瀬 健太郎; Orlandi, R.; Leguillon, R.*; 小川 達彦; Soldner, T.*; Hambsch, F.-J.*; Frost, R. J. W.*; Tsekhanovich, I.*; et al.
no journal, ,
仏国ラウエ・ランジュバン研究所にある高中性子束炉からの大強度中性子ビームを用いてU熱中性子誘起核分裂に伴い発生する線をおおよそ20MeVまでのエネルギー領域で測定した。得られた線スペクトルにはいくつかの局所的な構造が観測された。これらの構造の起源について統計模型計算による考察を行ったので、報告する。
