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針井 一哉*; 埋田 真樹; 有沢 洋希*; 日置 友智*; 佐藤 奈々; 岡安 悟; 家田 淳一
Journal of the Physical Society of Japan, 92(7), p.073701_1 - 073701_4, 2023/07
被引用回数:0 パーセンタイル:0.01(Physics, Multidisciplinary)Magnetic property modification of an easy-plane magnetic insulator caused by an accumulation of nanocolumnar defects along the film normal was investigated by numerical simulations and heavy-ion beam irradiation experiments. Micromagnetic simulations suggest that depending on the density of the nonmagnetic nanocolumnar defects, the microstructure of the fragmented ferromagnetic domains is formed leading to magnetic coercivity enhancement as well as magnetization reduction. To prove this prediction, gold ions with 300 MeV were used for the irradiation to create amorphous nanocolumnar defects in crystalline bismuth-doped lutetium iron garnet (Bi:LuIG) films. As increasing the ion-irradiation dose, the modifications of the saturation magnetization and magnetic coercivity were observed in an uncorrelated manner; the enhancement of magnetic coercivity exhibits a fluence threshold whereas the decrease of saturation magnetization caused by ion-beam damage is monotonic with increasing beam fluence. These behaviors qualitatively agree with the numerical simulations and the models by continuum percolation theory. Because the irradiation effects are controlled by beam fluences, the present method has the potential to be a microstructuring technique for magnetic insulator.
七村 拓野; 藤田 真奈美; 長谷川 勝一; 市川 真也; 市川 裕大; 今井 憲一*; 成木 恵; 佐藤 進; 佐甲 博之; 田村 裕和; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(9), p.093D01_1 - 093D01_35, 2022/09
被引用回数:1 パーセンタイル:57.36(Physics, Multidisciplinary)We performed a novel scattering experiment at the J-PARC Hadron Experimental Facility. Approximately 2400
elastic scattering events were identified from
tagged
particles in the
momentum range 0.44 - 0.80 GeV/c. The differential cross sections of the
elastic scattering were derived with much better precision than in previous experiments. The obtained differential cross sections were approximately 2 mb/sr or less, which were not as large as those predicted by the fss2 and FSS models based on the quark cluster model in the short-range region. By performing phase-shift analyses for the obtained differential cross sections, we experimentally derived the phase shifts of the
and
channels for the first time. The phase shift of the 3S1 channel, where a large repulsive core was predicted owing to the Pauli effect between quarks, was evaluated to be
. If the sign of
is assumed to be negative, the interaction in this channel is moderately repulsive, as the Nijmegen extended-sort-core models predicted.
三輪 浩司*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; 佐藤 進; et al.
Physical Review C, 104(4), p.045204_1 - 045204_20, 2021/10
被引用回数:9 パーセンタイル:89.08(Physics, Nuclear)A high statistics scattering experiment is performed at the J-PARC Hadron Experimental Facility. Momentum-tagged
s running in a liquid hydrogen target are accumulated by detecting the reaction with a high intensity
beam of 20 M/spill. The differential cross sections of the
elastic scattering were derived with a drastically improved accuracy by identifying approximately 4,500 events from 1.72
10
. The derived differential cross section shows a clear forward-peaking angular distribution for a
momentum range from 470 to 850 MeV/
. The accurate data will impose a strong constraint on the theoretical models of the baryon-baryon interactions.
吉本 雅浩*; 藤田 真奈美; 橋本 直; 早川 修平; 市川 裕大; 市川 真也; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Progress of Theoretical and Experimental Physics (Internet), 2021(7), p.073D02_1 - 073D02_19, 2021/07
被引用回数:8 パーセンタイル:74.27(Physics, Multidisciplinary)Bound-systems of -
are studied via
capture at rest followed by emission of a twin single-
hypernucleus in the emulsion detectors. Two events forming extremely deep
bound states were obtained by analysis of a hybrid method in the E07 experiment at J-PARC and reanalysis of the E373 experiment at KEK-PS. The decay mode of one event was assigned as
+
+
+
. Since there are no excited states for daughter particles, the binding energy of the
hyperon,
, in
nucleus was uniquely determined to be 6.27
0.27 MeV. Another
-
system via the decay
+
+
brings a
value, 8.00
0.77 MeV or 4.96
0.77 MeV, where the two possible values of
correspond to the ground and the excited states of the daughter
nucleus, respectively. Because the
values are larger than those of the previously reported events (KISO and IBUKI), which are both interpreted as the nuclear
state of the
-
system, these new events give the first indication of the nuclear
state of the
hypernucleus,
.
坂尾 珠和*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
JPS Conference Proceedings (Internet), 33, p.011133_1 - 011133_6, 2021/03
The reaction is an important elementary process to produce
from a proton target and is a key for a
scattering experiment where the momentum of
should be tagged from the missing momentum of the
reaction. However, the
spectroscopy method has not been established yet due to the difficulty of the
detection. Therefore, we have proposed a new
detection method where
and
from the
decay are measured by a forward magnetic spectrometer and a detector cluster surrounding the target, respectively. The feasibility of the
detection method was confirmed by analyzing the J-PARC E40 data taken with such a detector system. In the analysis,
's were successfully identified in the missing mass spectrum of the
reaction.
早川 修平; 藤田 真奈美; 長谷川 勝一; 橋本 直; 細見 健二; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Physical Review Letters, 126(6), p.062501_1 - 062501_6, 2021/02
被引用回数:28 パーセンタイル:95.36(Physics, Multidisciplinary)In an emulsion-counter hybrid experiment performed at J-PARC, a absorption event was observed which decayed into twin single-
hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as
N
Be +
He. For the binding energy of the
hyperon in the
-
N system a value of
MeV was deduced. The energy level of
is likely a nuclear
state which indicates a weak
-
coupling.
後神 利志*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 今井 憲一*; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; 佐藤 進; et al.
Journal of Physics; Conference Series, 1643, p.012133_1 - 012133_6, 2020/12
被引用回数:0 パーセンタイル:63.81We performed hypernuclear spectroscopy with the
reaction at J-PARC to investigate the
interaction (J-PARC E05). A new experiment (J-PARC E70) in which a better energy resolution could be achieved is now being prepared. In this article, an analysis status of J-PARC E05 and a preparation status of J-PARC E70 are described.
三輪 浩司*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Journal of Physics; Conference Series, 1643, p.012174_1 - 012174_6, 2020/12
被引用回数:2 パーセンタイル:82.61A high statistics scattering experiment has been performed at the K1.8 beamline in the J-PARC Hadron Experimental Facility. Data for momentum-tagged
beam running in a liquid hydrogen target were accumulated by detecting the
reaction with a high intensity
beam of 20 M/spill. The number of the
beam was about
in total. The
elastic scattering and the
inelastic scattering events were successfully observed with about 100 times larger statistics than that in past experiments.
中田 祥之*; 長谷川 勝一; 早川 修平*; 細見 健二; 市川 裕大; 今井 憲一; 七村 拓野*; 成木 恵*; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 26, p.023024_1 - 023024_5, 2019/11
J-PARC E40 aims to measure the differential cross sections of the elastic scatterings and the
conversion. A clear peak of
was observed in a missing mass spectrum of the
reaction and recoil protons from the
elastic scattering were successfully observed in the data taken in the summer 2018. The rest of data taking is coming in the spring 2019.
本多 良太郎*; 長谷川 勝一; 早川 修平; 細見 健二; 今井 憲一; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 26, p.023014_1 - 023014_4, 2019/11
We measured the reaction spectra at 1.8 GeV/
for the graphite and the polyethylene targets in the J-PARC E05 pilot experiment. By comparing the spectra for these two targets, it was found that
in the
B nucleus is quite broadened. Furthermore, we also compared broadness of
with
obtained in the
spectrum.
seems to be much more broadened in nuclei than
. We gave a possible interpretation, which is related to compositeness of decuplet baryons, for this situation.
Kim, S. H.*; 市川 裕大; 佐甲 博之; 長谷川 勝一; 早川 修平*; 七村 拓野*; 佐藤 進; 谷田 聖; 吉田 純也; 他11名*
Nuclear Instruments and Methods in Physics Research A, 940, p.359 - 370, 2019/10
被引用回数:5 パーセンタイル:52.09(Instruments & Instrumentation)We have developed a gas electron multiplier (GEM)-based time projection chamber (TPC) for the H-dibaryon search experiment at J-PARC. High-rate beam particles enter a TPC gas volume of approximately 0.2 m
, in a direction perpendicular to the electric field. A long-rectangular hollow section is located inside the TPC volume to accommodate a diamond target. We commissioned the TPC using 230 MeV protons with beam rates of up to 1 MHz. The TPC data acquisition system collected 5768 pad signals in full readout mode, with almost 100% efficiency, at a preset trigger rate of 230 Hz. We operated the TPC in an Ar/CH
gas mixture (90/10) without a magnetic field. The spatial resolutions on the pad plane are measured to be 400-700
m, which correspond to 230-300
m in a magnetic field of 1 T. We confirmed high tracking capability at beam rates of up to 1 MHz.
永江 知文*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 金原 慎二; 七村 拓野*; 成木 恵; et al.
AIP Conference Proceedings 2130, p.020015_1 - 020015_9, 2019/07
被引用回数:11 パーセンタイル:98.69For the full understanding of baryon-baryon interactions in flavor , the
interaction is the last missing piece of information. So far, we have revealed the
interaction to be attractive (
MeV), and
interaction to be repulsive in the medium to heavy mass-number region. The
bonding energy is weakly attractive. While we have a few experimental observations suggesting the
interaction would be attractive, there still exist large theoretical ambiguities weather it is attractive or not. Experimental determinations on the existence of bound states of
hypernuclei by observing bound-state peaks are strongly awaited. In this report, a new preliminary result on the missing-mass spectrum of a
C
reaction, which strongly suggests the existence of
-hypernuclear bound states, is presented.
江川 弘行; 足利 沙希子; 長谷川 勝一; 橋本 直; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 金原 慎二*; 七村 拓野; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.021D02_1 - 021D02_11, 2019/02
被引用回数:23 パーセンタイル:83.91(Physics, Multidisciplinary)A double- hypernucleus,
, was observed by the J-PARC E07 collaborationin nuclear emulsions tagged by the
reaction. This event was interpreted as a production and decay of
,
, or
via
capture in
.By assuming the capture in the atomic 3D state, the binding energy of two
hyperons
(
)of these double-
hypernuclei are obtained to be
,
, and
, respectively. Based on the kinematic fitting,
is the most likely explanation for the observed event.
片岡 龍峰*; 西山 尚典*; 田中 良昌*; 門倉 昭*; 内田 ヘルベルト陽仁*; 海老原 祐輔*; 江尻 省*; 冨川 喜弘*; 堤 雅基*; 佐藤 薫*; et al.
Earth, Planets and Space (Internet), 71, p.9_1 - 9_10, 2019/01
被引用回数:7 パーセンタイル:38.8(Geosciences, Multidisciplinary)2017年6月30日22時21分から26分(世界時)にかけて、昭和基地にあるPANSYレーダーによってオーロラ爆発時の中間圏における過渡電離が観測された。通常、中間圏における過渡電離は100keV以上の高エネルギー電子が中間圏まで到達することにより引き起こされるが、同時間帯においてあらせ衛星が観測した100keV以上の電子フラックスは有意な上昇を示していなかった。このことから、本イベントは、10keV以下の低エネルギー電子が大量に熱圏に降り注ぐことにより発生したX線による電離であるとの仮説を立てた。この仮説の妥当性を検証するため、粒子・重イオン挙動解析コードPHITSを用いて様々なエネルギースペクトルを持つ電子が大気上空に進入した場合の電離分布を計算した。その結果、10keV以下の電子でも中間圏において十分な電離を引き起こすことが可能であることが分かり、仮説の妥当性が証明された。
原賀 智子; 大内 和希; 佐藤 義行; 星野 仁*; 田中 玲*; 藤原 隆司*; 黒川 秀樹*; 渋川 雅美*; 石森 健一郎; 亀尾 裕; et al.
Analytica Chimica Acta, 1032, p.188 - 196, 2018/11
被引用回数:12 パーセンタイル:48.27(Chemistry, Analytical)放射性試料中のアクチノイドイオンを安全、迅速、高感度に分析するため、蛍光プローブを用いたキャピラリー電気泳動法による分析法を開発した。本研究では、化学ライブラリーを用いて、アクチノイドイオンの検出に必要となる蛍光プローブを選択し、大環状および非環状の多座配位骨格を有するプローブ群を整備した。アクチノイドのうち、ウラニルイオンに対して、4座の配位骨格を有する蛍光プローブを用いることにより、従来のキャピラリー電気泳動法の検出限界(ppmレベル)を大幅に改善し、pptレベルの検出限界を達成するとともに、実際の放射性廃液試料の分析に適用できることも示した。
後神 利志*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 今井 憲一; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; et al.
JPS Conference Proceedings (Internet), 18, p.011031_1 - 011031_6, 2017/11
The missing mass spectroscopy of hypernuclei is planned at the Japan Proton Accelerator Research Complex (J-PARC) by using the
reaction. We are constructing a new magnetic spectrometer, S-2S, which has a better momentum resolution [
(FHWM)] than that of an existing spectrometer (SKS) at J-PARC. S-2S would give us an opportunity to confirm the existence of
hypernuclei as a peak structure owing to both the high momentum resolution and its reasonably large solid angle. Brief descriptions of our experiment and of its preparation status are presentedin this article.
林 久史*; 川田 雅輝*; 佐藤 敦*; 宇田川 康夫*; 稲見 俊哉; 石井 賢司; 小笠原 春彦*; 七尾 進*
Physical Review B, 72(4), p.045114_1 - 045114_5, 2005/07
被引用回数:12 パーセンタイル:47.97(Materials Science, Multidisciplinary)HoO
の2
3
共鳴非弾性X線散乱スペクトルをエネルギー分解能0.7eVで測定し、Kramers-Heisenberg形式をもとにした式で解析した。内殻ホールの寿命幅(4.26eV)による幅の広がりは完全に抑えられ、位置の不確定さ0.3eVで幅0.5eV以下の鋭い吸収スペクトルが得られた。観測されたピークはよく知られた2
4
四重極遷移に帰属され、これらは通常強い2
5
双極子遷移に埋もれている。この手法により4
-5
相互作用をより精密に研究する道が開けたと言える。
高橋 嘉夫*; 吉田 英一; Sato, Nana*; 濱 克宏; 湯佐 泰久; 清水 洋
Chemical Geology, 184(3-4), p.311 - 335, 2002/00
被引用回数:134 パーセンタイル:90.58(Geochemistry & Geophysics)地下深部における希土類元素の挙動を把握するために、土岐花崗岩・瑞浪層群および地下水中の希土類元素の分布パターンを調査した。その結果、今回分析を行った全ての岩石および地下水についてテトラド効果が認められた。岩石、地下水に認められるWまたはM型のテトラド効果から、瑞浪層群中に存在する希土類元素は、土岐花崗岩から地下水により供給された可能性があることが考えられた。
原賀 智子; 大内 和希; 佐藤 義行; 星野 仁*; 田中 玲*; 藤原 隆司*; 黒川 秀樹*; 渋川 雅美*; 石森 健一郎; 亀尾 裕; et al.
no journal, ,
放射性試料中のアクチノイドイオンを高感度に分析するため、蛍光プローブを用いたキャピラリー電気泳動法による分析法を開発した。本研究では、化学ライブラリーを用いて、アクチノイドイオンの高感度検出に必要となる大環状および非環状の多座配位骨格を有する蛍光プローブ群を整備した。ウラニルイオンに対しては、4座の配位骨格を有する蛍光プローブを用いることにより、従来のキャピラリー電気泳動法の検出限界(ppmレベル)を大幅に改善し、pptレベルの検出限界を達成するとともに、実際の放射性廃液試料の分析に適用できることを示した。
佐藤 奈々; Schultheiss, K.*; Krber, L.*; Puwenberg, N.*; M
hl, T.*; Awad, A. A.*; Arekapudi, S. S. P. K.*; Hellwig, O.*; Fassbender, J.*; Schultheiss, H.*
no journal, ,
In the last decade, two revolutionary concepts in nano magnetism emerged from research for advanced information processing and storage technologies. The first suggests the use of magnetic domain walls (DWs) in ferromagnetic nanowires to permanently store information in DW racetrack memories. The second proposes a hardware realisation of neuromorphic computing in nanomagnets using nonlinear magnetic oscillations in the GHz range. Both ideas originate from the transfer of angular momentum from conduction electrons to localised spins in ferromagnets, either to push data encoded in DWs along nanowires or to sustain magnetic oscillations in artificial neurones. Even though both concepts share a common ground, they live on very different time scales which rendered them incompatible so far. Here, we bridge both ideas by demonstrating the excitation of magnetic auto-oscillations inside nano-scale DWs using pure spin currents.