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Vu, TheDang*; 宍戸 寛明*; 相澤 一也; 奥 隆之; 及川 健一; 原田 正英; 小嶋 健児*; 宮嶋 茂之*; 曽山 和彦; 小山 富男*; et al.
IEEJ Transactions on Electrical and Electronic Engineering, 19(11), p.1888 - 1894, 2024/11
被引用回数:0 パーセンタイル:0.00(Engineering, Electrical & Electronic)We proposed a novel superconducting detector called the current-biased kinetic inductance detector (CB-KID) for constructing a neutron transmission imager. We systematically studied the characteristics of the CB-KID to improve spatial resolution down to 10 m in transmission imaging. By analyzing neutron transmission spectra from 1 meV to 500 keV, we identified copper (Cu) and iron (Fe) as major components in commercial nuts and screws. Additionally, we successfully mapped the distribution of the SmSn
compound using selective energy regions of pulsed neutrons and the CB-KID detector. It can reveal transmission spectra across a wide range of energies, from cold-neutron energies (meV) to higher neutron energies (up to 500 keV).
Vu, TheDang*; 宍戸 寛明*; 相澤 一也; 奥 隆之; 及川 健一; 原田 正英; 小嶋 健児*; 宮嶋 茂之*; 曽山 和彦; 小山 富男*; et al.
Journal of Physics; Conference Series, 2776, p.012009_1 - 012009_9, 2024/06
We optimized the design and operating conditions of our superconducting neutron detector to improve spatial resolution. We obtained the best spatial resolution of 10 m when a Gd Siemens star pattern was mounted at close contact with the detector in the cryostat. We compared the effect of a different sample-detector distance on a spatial resolution when the samples were placed either at cryogenic temperature or at room temperature. We found the appearance of clear Bragg dips by the measurements of natural FeS
single crystals and succeeded in mapping the distribution of differently-oriented crystals by choosing several Bragg dips of the FeS
crystals to compose the transmission images.
石田 武和*; Vu, TheDang*; 宍戸 寛明*; 相澤 一也; 奥 隆之; 及川 健一; 原田 正英; 小嶋 健児*; 宮嶋 茂之*; 小山 富男*; et al.
Journal of Low Temperature Physics, 214(3-4), p.152 - 157, 2024/02
被引用回数:0 パーセンタイル:0.00(Physics, Applied)We built a new cryostat to apply a current-biased kinetic inductance detector (CB-KID) for conducting neutron transmission imaging of room temperature samples under pulsed neutrons. A Wood's metal alloy of melting temperature 75.2C was placed at room temperature to inspect the measurement system at J-PARC. Since one of the four phases of Wood's metal is a fine Cd-rich needle phase (width
25
m and length
5 mm), it is suitable for observing fine mosaic structure selectively by neutron imaging. The spatial resolution of the CB-KID imager was estimated as
10
m by using a Gd Siemens-star pattern. The CB-KID system is useful to conduct transmission imaging for various materials rather easily at room temperature.
宍戸 寛明*; Vu, TheDang*; 相澤 一也; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 奥 隆之; 曽山 和彦; 宮嶋 茂之*; et al.
Journal of Applied Crystallography, 56(4), p.1108 - 1113, 2023/08
被引用回数:2 パーセンタイル:52.57(Chemistry, Multidisciplinary)Recent progress in high-power pulsed neutron sources has stimulated the development of the Bragg dip and Bragg edge analysis methods using a two-dimensional neutron detector with high temporal resolution to resolve the neutron energy by the time-of-flight method. A delay-line current-biased kinetic inductance detector (CB-KID) is a two-dimensional superconducting sensor with a high temporal resolution and multi-hit capability. Here, it is demonstrated that a delay-line CB-KID with a B neutron conversion layer can be applied to high-spatial-resolution neutron transmission imaging and spectroscopy up to 100 eV. Dip structures are observed in the transmission spectra of YbSn
single crystals, induced by Bragg diffraction and nuclear resonance absorption. The orientation mapping of YbSn
crystals is successfully drawn based on the analysis of observed Bragg dip positions in the transmission spectra.
宍戸 寛明*; 西村 和真*; Vu, TheDang*; 相澤 一也; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 奥 隆之; 曽山 和彦; et al.
IEEE Transactions on Applied Superconductivity, 31(9), p.2400505_1 - 2400505_5, 2021/12
被引用回数:0 パーセンタイル:0.00(Engineering, Electrical & Electronic)中性子イメージングは、重金属に対する高透過性、軽元素に対する高感度、同位体と中性子との特異な核反応による同位体選択性などの中性子ビームの特徴を活かした非破壊検査の有力な手段の一つである。本研究では、超伝導検出器である電流バイアス運動インダクタンス検出器(CB-KID)を用いて、パルス中性子源を用いた飛行時間法による波長分解中性子イメージングを行った。遅延時間型CB-KIDを用いて、GdAl単結晶を成長させたGd-Al合金試料の中性子透過像を取得した。その結果、単結晶はAl-Gd合金全体に渡って、形状,分布ともに良好に観察することができた。また、中性子の波長0.03nm以上でGdによる特徴的な中性子の吸収を確認した。さらに、15
m
12
mという限られた検出面で、同位体と中性子の核反応によって生じる
Gd共鳴ディップを観測することができた。また、
Gdの共鳴ディップを用いてGd選択的イメージングを行ったところ、中性子の波長幅が1pmという限られた範囲で、明確なGd核の元素選択イメージング像を取得することに成功した。
Vu, TheDang; 宍戸 寛明*; 相澤 一也; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 奥 隆之; 曽山 和彦; 宮嶋 茂之*; et al.
Nuclear Instruments and Methods in Physics Research A, 1006, p.165411_1 - 165411_8, 2021/08
被引用回数:1 パーセンタイル:14.80(Instruments & Instrumentation)We found that the sizes of the Gd islands determined from the transmission image correlated strongly with those determined from the SEM image. We demonstrated the CB-KID could be used to identify (1) tiny voids in a thermally sprayed continuous GdO
film in and (2) various mosaic morphologies and different eutectic microstructures in Wood's metal samples. The fact that the CB-KID system could be used to identify features of samples with a wide distribution of sizes and thicknesses is promising for real application of the device for imaging samples of interest to material scientists. Operating the CB-KID at higher temperatures appreciably improved the efficiency for simultaneously identifying the X and Y positions of hotspots. We also compared the detection efficiency with the PHITS simulations. We now plan to improve the detection efficiency by increasing the thickness of the
B neutron conversion layer
宍戸 寛明*; Vu, TheDang*; 相澤 一也; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 奥 隆之; 曽山 和彦; 宮嶋 茂之*; et al.
Journal of Physics; Conference Series, 1975, p.012023_1 - 012023_8, 2021/07
被引用回数:0 パーセンタイル:0.00(Engineering, Electrical & Electronic)The current-biased kinetic-inductance detector (CB-KID) is a solid-state superconducting neutron detector with high spatial and temporal resolutions, and multi-hit tolerance. We demonstrate high temperature operation of CB-KID at 7.9 K with the delayline method. High temperature operation reduces imaging pixel size by suppressing signal propagation velocity. High spatial neutron transmission image for a mixed metal alloy consisting of heavy elements Sm and Sn is successfully constructed. We also examine the capability of element discrimination imaging based on the resonance dip analysis.
Vu, TheDang; 宍戸 寛明*; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 宮嶋 茂之*; 奥 隆之; 曽山 和彦; 相澤 一也; et al.
Superconductor Science and Technology, 34(1), p.015010_1 - 015010_10, 2021/01
被引用回数:4 パーセンタイル:27.02(Physics, Applied)We demonstrated that a four-readout superconducting neutron imaging system shows good spatial heterogeneity and linearity using the delay-line method. We examined the precise pattern of a B-dot-array absorber and found the X-direction pitch (Px) = 250.7 um with a scatter of (Hx)= 5.4 um and the Y-direction pitch (Py)= 249.1 um with a scatter of (Hy)= 3.4 um while the
B dot array was fully extended toward the X direction across the detector sensitive area. We consider that this demonstrates detection with good spatial homogeneity and conclude. The transmission-imaging system is suitable for use at pulsed neutron facilities. We also reported a clear transmission image of tiny screws and nuts, and ladybug (insect). We recognize that further efforts to improve the detection efficiency are necessary to make using the detector more practical.
宍戸 寛明*; 西村 和真*; Vu, TheDang*; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 宮嶋 茂之*; 日高 睦夫*; 奥 隆之; et al.
Journal of Physics; Conference Series, 1590, p.012033_1 - 012033_8, 2020/10
被引用回数:0 パーセンタイル:0.00(Engineering, Electrical & Electronic)We demonstrate the development of an energy resolved neutron transmission imaging system via a solid-state superconducting detector, called current-biased kinetic-inductance detector (CB-KID). CB-KIDs comprise X and Y superconducting Nb meanderlines with Nb ground plane and a B conversion layer, which converts a neutron to two charged particles. CB-KID uses the delay-line method, and allows us to reconstruct the two-dimensional neutron transmission image of a test sample with four signal readout lines. We examined the capability of high spatial and energy (wavelength) resolved neutron transmission imaging over the sensor active area of 15
15 mm
for various samples, including biological and metal ones. We also demonstrated the capability for the Bragg edge transmission and an energy-resolved neutron image in which stainless-steel specimens were discriminating from other specimens.
Vu, TheDang; 西村 和真*; 宍戸 寛明*; 原田 正英; 及川 健一; 宮嶋 茂之*; 日高 睦夫*; 奥 隆之; 曽山 和彦; 相澤 一也; et al.
Journal of Physics; Conference Series, 1590, p.012036_1 - 012036_9, 2020/07
被引用回数:1 パーセンタイル:63.53(Engineering, Electrical & Electronic)Our CB-KID neutron imager detects high spatial resolution neutrons transmission images by using a delay-line technique. We found that the number of events was remarkably increased with increasing the detector temperature until close to the critical temperature Tc. We investigated the properties of CB-KID at near Tc. We observed systematic changes of neutron signals as a function of the detector temperature from 4 K to Tc. The simulations modeled the sequential physical processes for B(n,
)
Li reactions and energy deposition by particles within CB-KID, including neutrons,
He particles,
Li particles, photon and electron transport.
Malins, A.; 町田 昌彦; Vu, TheDang; 相澤 一也; 石田 武和*
Nuclear Instruments and Methods in Physics Research A, 953, p.163130_1 - 163130_7, 2020/02
被引用回数:6 パーセンタイル:52.74(Instruments & Instrumentation)Radiation transport simulations were used to analyse neutron imaging with the current-biased kinetic inductance detector (CB-KID). The PHITS Monte Carlo code was applied for simulating neutron, He,
Li, photon and electron transport,
B(n,
)
Li reactions, and energy deposition by particles within CB-KID. Slight blurring in simulated CB-KID images originated
He and
Li ions spreading out in random directions from the
B conversion layer in the detector prior to causing signals in the
and
superconducting Nb nanowire meander lines. 478 keV prompt gamma rays emitted by
Li nuclei from neutron-
B reactions had negligible contribution to the simulated CB-KID images. Simulated neutron images of
B dot arrays indicate that sub 10
m resolution imaging should be feasible with the current CB-KID design. The effect of the geometrical structure of CB-KID on the intrinsic detection efficiency was calculated from the simulations. An analytical equation was then developed to approximate this contribution to the detection efficiency. Detection efficiencies calculated in this study are upper bounds for the reality as the effects of detector temperature, the bias current, signal processing and dead-time losses were not taken into account. The modelling strategies employed in this study could be used to evaluate modifications to the CB-KID design prior to actual fabrication and testing, conveying a time and cost saving.
飯澤 侑貴*; 宍戸 寛明*; 西村 和真*; Vu, TheDang*; 小嶋 健児*; 小山 富男*; 及川 健一; 原田 正英; 宮嶋 茂之*; 日高 睦夫*; et al.
Superconductor Science and Technology, 32(12), p.125009_1 - 125009_8, 2019/12
被引用回数:14 パーセンタイル:56.29(Physics, Applied)Neutron imaging is one of the key technologies for non-destructive transmission testing. Recent progress in the development of intensive neutron sources allows us to perform energy-resolved neutron imaging with high spatial resolution. We have been developing a neutron imager aiming at conducting high spatial and temporal resolution imaging based on a delay-line neutron detector, called the current-biased kinetic-inductance detector, with a conversion layer B. The detector allowed us to obtain a neutron transmission image with four signal readout lines. Herein, we expanded the sensor active area, and improved the spatial resolution of the detector. We examined the capability of high spatial resolution neutron imaging over the sensor active area of 15
15 mm
for various samples, including biological and metal ones. We also demonstrated an energy-resolved neutron image in which stainless-steel specimens were discriminating of other specimens with the aid of the Bragg edge transmission.
Vu, TheDang; 飯澤 侑貴*; 西村 和真*; 宍戸 寛明*; 小嶋 健児*; 及川 健一; 原田 正英; 宮嶋 茂之*; 日高 睦夫*; 奥 隆之; et al.
Journal of Physics; Conference Series, 1293, p.012051_1 - 012051_9, 2019/10
被引用回数:6 パーセンタイル:93.91(Materials Science, Multidisciplinary)We succeeded in designed and fabricated a neutron detector by using a superconducting current-biased kinetic inductance detector (CB-KID), which is constructed by two perpendicular Nb-based superconducting meander-lines and an enriched B neutron conversion layer. We rebuilt completely a neutron image of a
B dot array contain in the stainless-steel mesh. To improve the resolution of neutron images, the characteristics of a superconducting neutron detector have been studied carefully. In this study, we present the dependence of neutron signals in the temperature of detector. We found that when the temperature of a neutron detector is as close as the critical temperature of superconductivity, the intensity of signal increase as a function of temperature. We consider that the ratio of noise and signal is decrease which is very useful to improve the resolution of neutron images.
宮嶋 茂之*; 宍戸 寛明*; 鳴神 吉人*; 吉岡 直人*; 藤巻 朗*; 日高 睦夫*; 及川 健一; 原田 正英; 奥 隆之; 新井 正敏*; et al.
Nuclear Instruments and Methods in Physics Research A, 842, p.71 - 75, 2017/01
被引用回数:13 パーセンタイル:74.66(Instruments & Instrumentation)We successfully derived the time-dependent flux of pulsed neutrons using a superconducting Nb-based current biased kinetic inductance detector (CB-KID) with a B conversion layer at Japan Proton Accelerator Research Complex. Our CB-KID is a meander line made of a 40-nm-thick Nb thin film with 1-
m line width, which is covered with a 150-nm-thick
B conversion layer. The detector works at a temperature below 4 K. The evaluated detection efficiency of the CB-KID in this experiment is 0.23% at the neutron energy of 25.4 meV. The time-dependent flux spectra of pulsed neutrons thus obtained are in good agreement with the results obtained by the Monte Carlo simulations.
岡安 悟; 片桐 政樹; 北條 喜一; 森井 幸生; 三木 重信*; 島影 久志*; Wang, Z.*; 石田 武和*
Physica C, 468(15-20), p.1998 - 2000, 2008/09
被引用回数:0 パーセンタイル:0.00(Physics, Applied)MgB超伝導体の超伝導転移端(TES)を利用した中性子センサーの開発を行っている。この目的のため低ノイズの測定系を開発してきた。この測定系の有用性を検証するため
Amを用いた
線検出を試みた。感度をかせぐため試料は1
m幅で35
mの長さの短いミアンダパターンを用いた。定電流モードで測定を行ったところ
線の検出に成功した。バイアス電流は6
Aであった。
石田 武和*; 西川 正利*; 藤田 賢文*; 岡安 悟; 片桐 政樹*; 佐藤 和郎*; 四谷 任*; 島影 久志*; 三木 茂人*; Wang, Z.*; et al.
Journal of Low Temperature Physics, 151(3-4), p.1074 - 1079, 2008/05
被引用回数:38 パーセンタイル:78.44(Physics, Applied)本論文では、ボロン同位体(質量数10)を増量した超伝導MgB中性子検出器は比較的高い温度で操作可能であることを示す。基本動作原理は、ボロン同位体が中性子をよく吸収し、核反応を起こすことで、超伝導転移近傍で大きな電気抵抗変化が瞬間的に起こることであり、実験用の原子炉から射出される冷中性子が高感度で検出可能となる。出力となる発生電位差については、デジタルオシロスコープを用いて低ノイズの増幅装置を用いることで十分に検出可能であることが分かった。また、詳細な上記核反応により起こる超伝導非平衡ダイナミクスについては、時間依存のギンツブルク・ランダウ方程式のシミュレーションをスーパーコンピュータ上で実施することにより追跡可能であり、観測事実とよく符号することが分かっている。
町田 昌彦; 叶野 琢磨*; 小山 富男*; 加藤 勝*; 石田 武和*
Journal of Low Temperature Physics, 151(1), p.58 - 63, 2008/04
被引用回数:12 パーセンタイル:47.39(Physics, Applied)本論文では、時間発展のギンツブルク・ランダウ方程式、マックスウエル方程式と熱伝導方程式を連立させてMgBの超伝導転移エッジにて中性子捕獲の後の非平衡超伝導ダイナミクスに対する大規模数値シミュレーションを行った結果について報告する。シミュレーションは電流バイアスの条件にて行われ、JRR-3にて実施された実験を説明するために実施されたが、得られた検出シグナルは、実験にて得られた観測シグナルとほぼ一致し、シミュレーションの正当性を十分に確認できるものとなった。この結果から、検出器のような極めて早いダイナミクスもシミュレーションにより実現できることが判明し、シミュレーションによる予測システムが十分に構築できることが分かった。
加藤 勝*; 小山 富男*; 町田 昌彦; 林 正彦*; 海老澤 丕道*; 石田 武和*
Physica B; Condensed Matter, 403(5-9), p.996 - 998, 2008/04
被引用回数:0 パーセンタイル:0.00(Physics, Condensed Matter)本論文発表では、ボゴリュウーボフ方程式を用いて、束縛条件での電子モデルを使い、引力相互作用を仮定することで、ナノ構造超伝導体の超伝導物性を理論的に研究した成果を発表する。上記方程式の数値シミュレーションにより、d波超伝導体のサイズを変えることで、様々な特性が変化し、特に、+
波の超伝導がコヒーレンス長の約10倍程度のサイズにおいて出現することを明らかにする。
中島 督*; 加藤 勝*; 小山 富男*; 町田 昌彦; 石田 武和*; Nori, F.*
Physica C, 468(7-10), p.769 - 772, 2008/04
被引用回数:4 パーセンタイル:20.95(Physics, Applied)d-ドットとは、d波超伝導体とs波超伝導体の2種類の超伝導体による複合ドット構造であり、両者の界面にて半磁束量子が形成されることが知られている。本論文発表では、この半磁束量子の時間変動を2成分ギンツブルク・ランダウ方程式を基に解析するシミュレーションについて述べた後、シミュレーションにより、d-ドットが論理回路デバイスとして動作することを明らかにする。また、複数のd-ドットの相互干渉についても、シミュレーションし、情報の交換がどのように行われるかを明らかにする。
石田 武和*; 松島 吉明*; 清水 誠*; 林 正彦*; 海老澤 丕道*; 佐藤 修*; 加藤 勝*; 小山 富男*; 町田 昌彦; 佐藤 和郎*; et al.
Physica C, 468(7-10), p.576 - 580, 2008/04
被引用回数:3 パーセンタイル:16.31(Physics, Applied)超伝導ネットワークの拡張リトルパークス効果は、磁場の関数として超伝導臨界温度が周期的に変動する現象である。本研究では、鉛を用いた蜂の巣格子と三角格子を電子線ビームリソグラフと蒸発鉛フィルムのリフトオフプロセスを組み合わせることで観測系を準備し、印可磁場を変動させて磁化をSQUIDを使って調べた。その結果、磁束跳躍の直接観察に初めて成功した。これは臨界温度の変動による超伝導臨界電流の変動が原因で磁束跳躍が起こることを直接観察したという点でインパクトが大きく、拡張リトルバークス効果の要因を初めて明らかにしたと言える成果である。