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Research on improvement of HTGR core power-density, 4; Feasibility study for a reactor core

沖田 将一朗; 水田 直紀; 高松 邦吉; 後藤 実; 吉田 克己*; 西村 洋亮*; 岡本 孝司*

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 10 Pages, 2023/05

Adoption of SiC-matrix fuel elements in future pin-in-block type HTGR designs will enhance oxidation resistance of the fuel element in the event of the air ingress accident, one of the most worrisome accidents in HTGRs. This would eliminate the need for the graphite sleeves used in the current pin-in-block type HTGR designs and enable high power density core designs with sleeveless and direct coolable fuel structure. Such a concept itself has been suggested by Japan Atomic Energy Agency (JAEA) in the past. However, JAEA has not yet demonstrated the feasibility for a core design with the SiC-matrix fuel elements. The present work is intended to demonstrate the feasibility for a new core design upgraded from an existing conceptual core design, called HTR50S, with 50 MW thermal power and reactor outlet temperature of 750$$^{circ}$$C. The new core design uses SiC-matrix fuel elements and increases the reactor power density to 1.2 times higher than the original HTR50S design. The feasibility is determined by whether the core satisfies the target values in nuclear and thermal-hydraulic designs by performing burn-up calculation with the whole core model and fuel temperature calculations. The calculation results showed that the new core design satisfied these target values on the reactor shutdown margin, the temperature coefficient of reactivity, and the maximum fuel temperature during normal operation.


Study of the $$N=32$$ and $$N=34$$ shell gap for Ti and V by the first high-precision multireflection time-of-flight mass measurements at BigRIPS-SLOWRI

飯村 俊*; Rosenbusch, M.*; 高峰 愛子*; 角田 佑介*; 和田 道治*; Chen, S.*; Hou, D. S.*; Xian, W.*; 石山 博恒*; Yan, S.*; et al.

Physical Review Letters, 130(1), p.012501_1 - 012501_6, 2023/01

 被引用回数:1 パーセンタイル:81.67(Physics, Multidisciplinary)

The atomic masses of $$^{55}$$Sc, $$^{56,58}$$Ti, and $$^{56-59}$$V have been determined using the high-precision multireflection time-of-flight technique. The radioisotopes have been produced at RIKEN's Radioactive Isotope Beam Factory (RIBF) and delivered to the novel designed gas cell and multireflection system, which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For $$^{56,58}$$Ti and $$^{56-59}$$V, the mass uncertainties have been reduced down to the order of 10 keV, shedding new light on the $$N=34$$ shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species $$^{58}$$Ti and $$^{59}$$V. With the new precision achieved, we reveal the nonexistence of the $$N=34$$ empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied $$nu$$p$$_{3/2}$$ orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the $$nu$$d$$_{5/2}$$ and $$nu$$g$$_{9/2}$$ orbits and compare the results with conventional shell model calculations, which exclude the $$nu$$g$$_{9/2}$$ and the $$nu$$d$$_{5/2}$$ orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at $$N = 34$$.


Mesospheric ionization during substorm growth phase

村瀬 清華*; 片岡 龍峰*; 西山 尚典*; 西村 耕司*; 橋本 大志*; 田中 良昌*; 門倉 昭*; 冨川 喜弘*; 堤 雅基*; 小川 泰信*; et al.

Journal of Space Weather and Space Climate (Internet), 12, p.18_1 - 18_16, 2022/06

 被引用回数:0 パーセンタイル:0.01(Astronomy & Astrophysics)



High spatial resolution neutron transmission imaging using a superconducting two-dimensional detector

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(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$$_{3}$$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$$mu$$m$$ times$$ 12$$mu$$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$$^{155}$$Gd共鳴ディップを観測することができた。また、$$^{155}$$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。



大戸 勤; 浅野 典一; 川俣 貴則; 箭内 智博; 西村 嵐; 荒木 大輔; 大塚 薫; 高部 湧吾; 大塚 紀彰; 小嶋 慶大; et al.

JAEA-Review 2020-018, 66 Pages, 2020/11


令和元年9月9日の台風15号の強風により、JMTR(材料試験炉)にある二次冷却系統冷却塔の倒壊事象が発生した。その倒壊に至った原因調査及び原因分析を行い、4つの原因が重なって起こったことが特定された。これを受け、JMTR内にある二次冷却系統冷却塔と同時期に設置された木造の冷却塔であるUCL(Utility Cooling Loop)系統冷却塔の健全性調査を行った。健全性調査項目は、UCL系統冷却塔の運転状態の把握、UCL冷却系統の構造材料の劣化状態、点検項目及び点検状況、過去の気象データの確認である。この調査結果から、当該設備を安全に維持・管理するため、点検項目の改善、UCL系統冷却塔の構造材料である木材の交換・補修計画及び今後のUCL系統冷却塔の使用計画を策定するとともに、既存UCL系統冷却塔に代わる新規冷却塔の更新計画を策定した。本報告書はこれらの健全性調査の結果をまとめたものである。


Kinetic inductance neutron detector operated at near critical temperature

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:0 パーセンタイル:0.01

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 $$^{10}$$B(n,$$alpha$$)$$^{7}$$Li reactions and energy deposition by particles within CB-KID, including neutrons, $$^{4}$$He particles, $$^{7}$$Li particles, photon and electron transport.


Energy-resolved neutron imaging with high spatial resolution using a superconducting delay-line kinetic inductance detector

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:11 パーセンタイル:57.47(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 $$^{10}$$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 $$times$$ 15 mm$$^{2}$$ 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.


Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

園田 哲*; 片山 一郎*; 和田 道治*; 飯村 秀紀; Sonnenschein, V.*; 飯村 俊*; 高峰 愛子*; Rosenbusch, M.*; 小島 隆夫*; Ahn, D. S.*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2019(11), p.113D02_1 - 113D02_12, 2019/11


 被引用回数:1 パーセンタイル:12.78(Physics, Multidisciplinary)



Temperature dependent characteristics of neutron signals from a current-biased Nb nanowire detector with $$^{10}$$B converter

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:5 パーセンタイル:94.62

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 $$^{10}$$B neutron conversion layer. We rebuilt completely a neutron image of a $$^{10}$$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.


New precise measurements of muonium hyperfine structure at J-PARC MUSE

Strasser, P.*; 阿部 充志*; 青木 正治*; Choi, S.*; 深尾 祥紀*; 東 芳隆*; 樋口 嵩*; 飯沼 裕美*; 池戸 豊*; 石田 勝彦*; et al.

EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01

 被引用回数:13 パーセンタイル:99.42

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.


New muonium HFS measurements at J-PARC/MUSE

Strasser, P.*; 青木 正治*; 深尾 祥紀*; 東 芳隆*; 樋口 嵩*; 飯沼 裕美*; 池戸 豊*; 石田 勝彦*; 伊藤 孝; 岩崎 雅彦*; et al.

Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12

 被引用回数:7 パーセンタイル:92.03

At the Muon Science Facility (MUSE) of J-PARC (Japan Proton Accelerator Research Complex), the MuSEUM collaboration is planning new measurements of the ground state hyperfine structure (HFS) of muonium both at zero field and at high magnetic field. The previous measurements were performed both at LAMPF (Los Alamos Meson Physics Facility) with experimental uncertainties mostly dominated by statistical errors. The new high intensity muon beam that will soon be available at MUSE H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation, and the results of a first commissioning test experiment at zero field are presented.


Feasible evaluation of neutron capture therapy for hepatocellular carcinoma using selective enhancement of boron accumulation in tumour with intra-arterial administration of boron-entrapped water-in-oil-in-water emulsion

柳衛 宏宣*; 熊田 博明*; 中村 剛実; 東 秀史*; 生嶋 一朗*; 森下 保幸*; 篠原 厚子*; 藤原 光輝*; 鈴木 実*; 櫻井 良憲*; et al.

Proceedings of 14th International Congress on Neutron Capture Therapy (ICNCT-14) (CD-ROM), p.157 - 160, 2010/10

In the treatment of hepatocellular carcinoma (HCC), only 30 % patients can be operated due to complication of liver cirrhosis or multiple intrahepatic tumours. Tumour cell destruction in BNCT is necessary to accumulate a sufficient quantity of $$^{10}$$B atoms in tumour cells. In this study, we prepared BSH entrapped WOW emulsion by double emulsifying technique using iodized poppy-seed oil (IPSO), BSH and surfactant, for selective intra-arterial infusion to HCC, and performed the neutron dosimetry using CT scan imaging of HCC patient. The $$^{10}$$B concentrations in VX-2 tumour obtained by delivery with WOW emulsion was superior to those by conventional IPSO mix emulsion. In case of HCC, we performed the feasibility estimation of 3D construction of tumor according to the CT imaging of a patient with epithermal neutron mode at JRR-4. Normal liver biologically weighted dose is restricted to 4.9 Gy-Eq; the max., min. and mean tumour weighted dose are 43.1, 7.3, and 21.8 Gy-Eq, respectively, in 40 minutes irradiation. In this study, we show that $$^{10}$$B entrapped WOW emulsion could be applied to novel intra-arterial boron delivery carrier for BNCT.


Transmission imaging and strain mapping in the vicinity of internal crack tip using synchrotron white X-ray

柴野 純一*; 梶原 堅太郎*; 桐山 幸治*; 菖蒲 敬久; 鈴木 賢治*; 西村 優*; 三浦 節男*; 小林 道明*

Materials Science Forum, 638-642, p.2476 - 2481, 2010/01

A transmission imaging and a strain mapping in the vicinity of a crack tip in steel were investigated using a high energy white X-ray obtained from BL28B2 beam line at SPring-8 in Japan. Low-alloy and high-tensile steel was used as a specimen prepared in the G-type geometry with a rectangular sectional part of 5 mm thickness for a four-point bending. As the results, the transmitted image of the crack showed that the crack in the specimen was propagated deeper than that on the surface. It became clear by the numerical simulation that the FWHM of diffracted X-ray profile measured near the crack tip was increased due to the steep change in the strain distribution. It was confirmed that the synchrotron white X-ray was useful for the imaging of the internal crack and the strain mapping near it.



柴野 純一*; 梶原 堅太郎*; 桐山 幸治; 菖蒲 敬久; 鈴木 賢治*; 西村 優*; 三浦 節男*; 小林 道明*

材料, 57(7), p.667 - 673, 2008/07

An imaging and a strain mapping in the vicinity of crack tip in materials were investigated using high energy white X-ray obtained from BL28B2 beam line at SPring-8 Japan. Low-alloy and high-tensile steel (JIS G3128 SHY685) was used as a specimen shaped into G-type and introduced a fatigue crack into the beam of it. As the results, the imaging of the crack of the length of about 1mm in the specimen with loading of crack opening is practicable by using high energy synchrotron white X-ray. The plastic region estimated from the distribution of FWHM almost agreed with the theoretical value calculated by fracture mechanics. It was confirmed that the high energy white X-ray was useful for the imaging of the crack and the strain mapping in the vicinity of it in the depth of the order of millimeter.


「数値解析による自由液面からのガス巻込み評価指針」の解説, 解説B(協力研究)

大島 宏之; 堺 公明; 上出 英樹; 木村 暢之; 江連 俊樹; 内堀 昭寛; 伊藤 啓; 功刀 資彰*; 岡本 孝司*; 田中 伸厚*; et al.

JAEA-Research 2008-049, 44 Pages, 2008/06




EUV light source by high power laser

井澤 靖和*; 西原 功修*; 田沼 肇*; 佐々木 明; 村上 匡且*; 砂原 淳*; 西村 博明*; 藤岡 慎介*; 青田 達也*; 島田 義則*; et al.

Journal of Physics; Conference Series, 112, p.042047_1 - 042047_4, 2008/00

 被引用回数:8 パーセンタイル:93.63



Studies of fast-ion transport induced by energetic particle modes using fast-particle diagnostics with high time resolution in CHS

磯部 光孝*; 東井 和夫*; 松下 啓行*; 後藤 和幸*; 鈴木 千尋*; 永岡 賢一*; 中島 徳嘉*; 山本 聡*; 村上 定義*; 清水 昭博*; et al.

Nuclear Fusion, 46(10), p.S918 - S925, 2006/10

 被引用回数:30 パーセンタイル:70.15(Physics, Fluids & Plasmas)

将来の核融合炉におけるアルファ粒子等の高速イオンによるMHD不安定性の励起とそれに伴うアルファ粒子の異常損失の危惧から、近年、高速粒子モード(EPM)やTAEモードといったMHD不安定性と高速イオンとの相互作用、並びにその結果生ずる高速イオン輸送・損失に関する研究が重要視されるようになってきている。核融合科学研究所のCompact Helical System(CHS)では、シンチレータを利用した高速イオンプローブ,高速中性粒子分析器、並びに多チャンネルHalpha光計測システム等を駆使して上記を研究対象とした実験を進めている。最近の研究から、中性粒子ビーム(NB)加熱プラズマにおいて発生するバースト的EPMモード(m/n=3/2)により、入射エネルギー近傍のエネルギーを持つ高速イオンのみが大半径方向外側へ排出されていることがわかった。磁場揺動レベルが最大に達した頃に高速イオンの排出が始まり、磁場揺動の周波数は、排出が始まると同時にダウンシフトを示す。高速イオン排出が収まるのとほぼ同時に磁場揺動も収まり、これらの観測結果は、このモードは入射エネルギー近傍の高速ビームイオンによりいわば共鳴的に励起されていることを示唆している。また、TAEモードについては、2機のNBを低密度プラズマに接線co-入射した場合に、顕著な高速イオンの排出が確認された。


Application of log interpretation methods to evaluate heterogeneity in diatomaceous mudstone at Horonobe area

原 彰男; 辻 隆司*; 西村 瑞恵*; 星 一良*; 八木 正彦*; 川田 耕司*; Hou, J.-Y.*

JAERI-Conf 2005-007, p.270 - 275, 2005/08



Application of Log Interpretation Methods to Evaluate Heterogeneity in Diatomaceous Mudstone at Horonobe Area

原 彰男; 辻 隆司*; 星 一良*; 八木 正彦*; 西村 瑞恵*; 川田 耕司*; Hou, J.-Y.*

International Symposium NUCEF2005, P. 65, 2005/02

幌延地域における堆積岩の不均質性を評価するため、自然$$gamma$$線検層とelectrical micro imaging(EMI)検層に着目し、堆積岩の物理特性と岩相の違いとの関係を把握するとともに、孔井対比を行い堆積岩の不均質性の空間分布の把握を試みた。本研究の結果、層理面が明瞭に判読できる堆積相AおよびBは自然$$gamma$$線量(以下GR値)が低い層準に発達し、かつSiO$$_{2}$$含有量が多くなる傾向にあるのに対し、層理面が不明瞭な堆積相DはGR値が高い層準に発達し、SiO$$_{2}$$含有量が少なくなる傾向にある。本解析結果は、原(2004)の指摘、すなわち、GR値の高い地層はAl$$_{2}$$O$$_{3}$$の含有量が高く粘土鉱物など陸源性の砕屑物に富むのに対し、GR値の低い地層はSiO$$_{2}$$の含有量が高く珪藻化石に富むことを支持している。また、自然ガンマ線検層およびEMI検層データに基づく堆積相について、孔井間対比を行うことにより、堆積物の堆積作用や地層の空間分布を推定する上で有意義な層厚分布の情報を得ることができた。


Effect of electron beam on velocities of uranium atomic beams produced by electron beam heating

大場 弘則; 小倉 浩一; 西村 昭彦; 田村 浩司; 柴田 猛順

Japanese Journal of Applied Physics, Part 1, 39(9A), p.5347 - 5351, 2000/09

 被引用回数:5 パーセンタイル:27.66(Physics, Applied)


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