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Martin, P. G.*; Jones, C. P.*; Bartlett, S.*; Ignatyev, K.*; Megson-Smith, D.*; 佐藤 志彦; Cipiccia, S.*; Batey, D. J.*; Rau, C.*; 末木 啓介*; et al.
Scientific Reports (Internet), 10, p.22056_1 - 22056_17, 2020/12
被引用回数：1 パーセンタイル：7.05(Multidisciplinary Sciences)The structural form and elemental distribution of material originating from different Fukushima Daiichi Nuclear Power Plant reactors (Units 1 and 3) is hereby examined to elucidate their contrasting release dynamics and the current in-reactor conditions to influence future decommissioning challenges. Complimentary computed X-ray absorption tomography and X-ray fluorescence data show that the two suites of Si-based material sourced from the different reactor Units have contrasting internal structure and compositional distribution. The known event and condition chronology correlate with the observed internal and external structures of the particulates examined, which suggest that Unit 1 ejecta material sustained a greater degree of melting than that likely derived from reactor Unit 3. In particular, we attribute the near-spherical shape of Unit 1 ejecta and their internal voids to there being sufficient time for surface tension to round these objects before the hot (and so relatively low viscosity) silicate melt cooled to form glass. In contrast, a more complex internal form associated with the sub-mm particulates invoked to originate from Unit 3 suggest a lower peak temperature, over a longer duration. Using volcanic analogues, we consider the structural form of this material and how it relates to its environmental particulate stability and the bulk removal of residual materials from the damaged reactors. We conclude that the brittle and angular Unit 3 particulate are more susceptible to further fragmentation and particulate generation hazard than the round, higher-strength, more homogenous Unit 1 material.
Martin, P.*; Alhaddad, O.*; Verbelen, Y.*; 佐藤 志彦; 五十嵐 康人*; Scott, T. B.*
Scientific Data (Internet), 7, p.282_1 - 282_8, 2020/08
被引用回数：2 パーセンタイル：16.07(Multidisciplinary Sciences)The 2011 accident at Japan's Fukushima Daiichi Nuclear Power Plant released a considerable inventory of radioactive material into the local and global environments. While the vast majority of this contamination was in the form of gaseous and aerosol species, of which a large component was distributed out over the neighbouring Pacific Ocean (where is was subsequently deposited), a substantial portion of the radioactive release was in particulate form and was deposited across Fukushima Prefecture. To provide an underpinning understanding of the dynamics of this catastrophic accident, alongside assisting in the off-site remediation and eventual reactor decommissioning activities, the "International Particle Analysis Database", or "IPAD", was established to serve as an interactive repository for the continually expanding analysis dataset of the sub-mm ejecta particulate. In addition to a fully interrogatable database of analysis results for registered users (exploiting multiple search methods), the database also comprises an open-access front-end for members of the public to engage with the multi-national analysis activities by exploring a streamlined version of the data.
Okeme, I. C.*; Scott, T. B.*; Martin, P. G.*; 佐藤 志彦; Ojonimi, T. I.*; Olaluwoye, M. O.*
Minerals (Internet), 10(3), p.241_1 - 241_15, 2020/03
被引用回数：7 パーセンタイル：54.69(Geochemistry & Geophysics)Natural radionuclide concentrations in coal and associated fly ash can occur at levels well in excess of those observed in other materials; enough to raise potential human and environmental health concerns when (re)suspended or incorporated into construction materials. To evaluate such concerns, this study characterised coal and fly ash samples obtained from two Nigerian coal mines (Okaba and Omelewu) using high resolution gamma spectroscopy combined with scanning electron microscopy and energy dispersive spectroscopy. Discrete uraninite particles were observed dispersed within the fly ash samples, alongside U and Th containing mineral grains (monazite, xenotime and zircon) with monazite the most abundant radioactive mineral particles. The pitted and cracked surface morphologies of these radioactive particles (with sizes between 10
m and 80m) indicates their susceptibility for disintegration into more dangerous and readily inhalable PM2.5 aerosol particles, with the potential to deliver localised dose and cause chronic respiratory diseases. While the results of activity concentrations and radiological hazard indices (radium equivalent, annual effective dose equivalent, total radium, and excess lifetime cancer risk) from Okaba and Omelewu coal samples were of no concern, results for the corresponding fly ash samples from both mines were between 3 and 5 times higher than internationally recommended safe limits. These results therefore imply that such coal-derived fly ash is not safe for incorporation in the construction of residential houses and should be properly disposed of or contained to prevent hazard due to increased risk of prolonged indoor exposure to gamma radiation, radon gas and inhalation of liberated radioactive particles.
Martin, P. G.*; Jones, C. P.*; Cipiccia, S.*; Batey, D. J.*; Hallam, K. R.*; 佐藤 志彦; Griffiths, I.*; Rau, C.*; Richards, D. A.*; 末木 啓介*; et al.
Scientific Reports (Internet), 10(1), p.1636_1 - 1636_11, 2020/01
被引用回数：8 パーセンタイル：34.78(Multidisciplinary Sciences)Both the three-dimensional internal structure and elemental distribution of near-field radioactive fallout particulate material released during the March 2011 accident at the Fukushima Daiichi Nuclear Power Plant is analysed using combined high-resolution laboratory and synchrotron radiation X-ray techniques. Results from this study allow for the proposition of the likely formation mechanism of the particles, as well as the potential risks associated with their existence in the environment, and the likely implications for future planned reactor decommissioning. A suite of particles is analyzed from a locality 2 km from the north-western perimeter of the site north of the primary contaminant plume in an area formerly attributed to being contaminated by fallout from reactor Unit 1. The particles are shown to exhibit significant structural similarities; being amorphous with a textured exterior, and containing inclusions of contrasting compositions, as well as an extensive internal void volume bimodal in its size distribution. A heterogeneous distribution of the various elemental constituents is observed inside a representative particle, which also exhibited a Fukushima-derived radiocesium (
Cs, 
Cs and 
Cs) signature with negligible natural Cs. We consider the structure and composition of the particle to suggest it formed from materials associated with the reactor Unit 1 building explosion, with debris fragments embedded into the particles surface. Such a high void ratio, comparable to geological pumice, suggests such material formed during a rapid depressurisation and is potentially susceptible to fragmentation through attrition.
Singh, B.*; Basunia, M. S.*; Martin, M.*; McCutchan, E. A.*; Bara, I.*; Caballero-Folch, R.*; Canavan, R.*; Chakrabarti, R.*; Chekhovska, A.*; Grinder, M. M.*; et al.
Nuclear Data Sheets, 160, p.405 - 471, 2019/09
被引用回数：10 パーセンタイル：71.88(Physics, Nuclear)The evaluated data are presented for 11 known A=218 nulcides (Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa and U). For 
Pb, Bi, At and Pa, data are available only for the ground states. For U, only the g.s. and a high-spin isomer are known, with no data on 
-ray transitions available. For Po, ten excited states are known from Bi decay, with no knowledge on the multipolarities of gamma-ray transitions. For Th, five excited states in the g.s. band are known from an in-beam -ray study. Data on level half-lives, multipolarities and mixing ratios of gamma transitions is generally lacking for A=218 nuclei. The static magnetic dipole moment has been measured for only an isomer in Fr. This evaluation was carried out as part of a joint IAEA-ICTP workshop for Nuclear Structure and Decay Data, organized and hosted by the IAEA, Vienna, and ICTP, Trieste, October 15-26, 2018.
Martin, P. G.*; Louvel, M.*; Cipiccia, S.*; Jones, C. P.*; Batey, D. J.*; Hallam, K. R.*; Yang, I. A. X.*; 佐藤 志彦; Rau, C.*; Mosselmans, J. F. W.*; et al.
Nature Communications (Internet), 10, p.2801_1 - 2801_7, 2019/06
被引用回数：26 パーセンタイル：77.9(Multidisciplinary Sciences)二次イオン質量分析(SIMS)測定とシンクロトロン放射(SR)分析技術を福島第一原子力発電所(FDNPP)の1号機原子炉由来のサブミリメートル粒状物質に対して分析を行った。これらの方法によりより大きなSiベースの放出物に含まれるミクロンスケールのU微粒子の分布、状態および同位体組成を調査することが可能であった。SRマイクロフォーカスX線蛍光(SR-micro-XRF)と吸収コントラストSRマイクロフォーカスX線トモグラフィー(SR-micro-XRT)を組み合わせることにより、U微粒子は粒子の外周の周りに位置することがわかった。高多孔質粒子これらの捕捉された粒子のいくつかのシンクロトロン放射マイクロフォーカスX線吸収端近傍構造(SR-micro-XANES)分析により、U(IV)酸化状態で存在することを明らかにした。このUが原発由来であることの確認は、FDNPPの1号機からの出所に特徴的な同位体濃縮比を有する二次イオン質量分析(SIMS)分析によって検証された。これらの結果は、使用済み燃料放出物が存在するという事象シナリオ(炉心1号機からある程度の炉心細分化および放出が起こったこと)の明確な証拠である。このUが環境や健康への危害を表す可能性は低いと予想されるが、将来的に母材であるSi含有バルク粒子の分解が生じると推定される。
Kim, S. B.*; Zhang, Y.*; Won, S. M.*; Bandodkar, A. J.*; 関根 由莉奈; Xue, Y.*; Koo, J.*; Harshman, S. W.*; Martin, J. A.*; Park, J. M.*; et al.
Small, 14(12), p.1703334_1 - 1703334_11, 2018/03
被引用回数：98 パーセンタイル：95.52(Chemistry, Multidisciplinary)This paper introduces super absorbent polymer valves and colorimetric sensing reagents as enabling components of soft, skin-mounted microfluidic devices designed to capture, store and chemically analyze sweat released from eccrine glands. The valving technology enables robust means for guiding the flow of sweat from an inlet location into a collection of isolated reservoirs, in a well-defined sequence. Analysis in these reservoirs involves a color responsive indicator of chloride concentration with a formulation tailored to offer stable operation with sensitivity optimized for the relevant physiological range. Evaluations on human subjects with comparisons against ex situ analysis illustrate the practical utility of these advances.
Matthi
, D.*; Ehresmann, B.*; Lohf, H.*; K
hler, J.*; Zeitlin, C.*; Appel, J.*; 佐藤 達彦; Slaba, T. C.*; Martin, C.*; Berger, T.*; et al.
Journal of Space Weather and Space Climate (Internet), 6, p.A13_1 - A13_17, 2016/03
被引用回数：65 パーセンタイル：93.52(Astronomy & Astrophysics)2012年8月6日以降、Mars Science Laboratory (MSL)に搭載された複合型放射線検出器(RAD)を用いて火星表面による放射線環境の測定が続けられている。本研究では、GEANT4, PHITS, HZETRN/OLTARISなど様々なコードを用いて火星表面における放射線環境を推定し、その結果とRADによる測定値を比較した。その結果、計算結果は測定値と概ねよい一致を示すものの、場合によっては大きく解離することが分かった。また、RADのデータは放射線輸送計算について、最適なインプットパラメータや物理モデルの最適な選択に役立つことも確認された。今回の解析結果は、今後、有人火星ミッションを計画する際、その被ばく線量評価や宇宙機遮へい設計などに活用することができる。
Passerini, S.*; Carardi, C.*; Grandy, C.*; Azpitarte, O. E.*; Chocron, M.*; Japas, M. L.*; Bubelis, E.*; Perez-Martin, S.*; Jayaraj, S.*; Roelofs, F.*; et al.
Proceedings of 2015 International Congress on Advances in Nuclear Power Plants (ICAPP 2015) (CD-ROM), p.780 - 790, 2015/05
The IAEA recently established a CRP on "Sodium properties and safe operation of experimental facilities in support of the development and deployment of Sodium Cooled Fast Reactors - NAPRO", to be carried out in the period 2013 - 2017. The first phase of the CRP is focused on the collection and assessment of sodium properties, and it will lead to a consistent property data set which will be published in the form of a handbook. This work is carried out by the 11 participating organizations from 10 Member States through the review and evaluation of the existing available data, the identification of the data gaps and the development of recommendations for experimental programmes to support closing these data gaps. A specific work package (WP 1.1), under the leadership of Argonne National Laboratory, is focused on the analysis of physical properties of sodium: thermodynamic properties and transport properties. The expected outcome includes the improved understanding of the availability, accuracy and range of applications of sodium properties centered on fast reactors and other technological applications. The implemented methodology for WP 1.1 is described and so the properties included in WP 1.1 and their classification. Major findings to date related to WP 1.1 are presented in this work, including detailed analysis of two selected properties.
Walsh, M.*; Andrew, P.*; Barnsley, R.*; Bertalot, L.*; Boivin, R.*; Bora, D.*; Bouhamou, R.*; Ciattaglia, S.*; Costley, A. E.*; Counsell, G.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
The ITER device is currently under construction. To fulfil its mission, it will need a set of measurement systems. These systems will have to be robust and satisfy many requirements hitherto unexplored in Tokamaks. Typically, diagnostics occupy either a removable item called a port plug, or installed inside the machine as an intricate part of the overall construction. Limited space availability has meant that many systems have to be grouped together. Installation of the diagnostic systems has to be closely planned with the overall schedule. This paper will describe some of the challenges and systems that are currently being progressed.
Reichle, R.*; Andrew, P.*; Counsell, G.*; Drevon, J.-M.*; Encheva, A.*; Janeschitz, G.*; Johnson, D. W.*; 草間 義紀; Levesy, B.*; Martin, A.*; et al.
Review of Scientific Instruments, 81(10), p.10E135_1 - 10E135_5, 2010/10
被引用回数：30 パーセンタイル：75.22(Instruments & Instrumentation)ITER will have wide angle viewing systems and a divertor thermography diagnostic which shall provide infrared coverage of the divertor and large parts of the first wall surfaces with spatial and temporal resolution adequate for operational purposes and higher resolved details of the divertor and other areas for physics investigations. We propose specifications for each system such that they jointly respond to the requirements. Risk analysis driven priorities for future work concern mirror degradation, interfaces with other diagnostics, radiation damage to refractive optics, reflections and the development of calibration and measurements methods for varying optical and thermal target properties.
Be halo nucleus from 
Bi at coulomb barrierMazzocco, M.*; Signorini, C.*; Romoli, M.*; De Francesco, A.*; Di Pietro, M.*; Vardaci, E.*; 吉田 光一*; 吉田 敦*; Bonetti, R.*; De Rosa, A.*; et al.
European Physical Journal A, 28(3), p.295 - 299, 2006/06
被引用回数：46 パーセンタイル：90.03(Physics, Nuclear)弱く束縛されたハロー核 BeのBによる散乱を40MeVで測定した。低強度・低エミッタンスの放射性ビームによる実験であったが、8個のSiテレスコープからなる大立体角(
2
sr)かつコンパクトな検出器により測定が可能となった。
Beの散乱角度分布と相対的な核反応断面積は、似たような振る舞いであることがわかった。このことは、クーロン障壁近傍におけるハロー構造あるいは弱く束縛された系の反応機構に与える影響は余り大きくないことを示唆するものである。
Martin, A. J.*; 梅田 浩司; Conner, C. B.*; Weller, J. N.*; Zhao, D*; 高橋 正樹*
Journal of Geophysical Research; Solid Earth, 109(B10), p.B10208_1 - B10208_20, 2004/10
被引用回数：60 パーセンタイル：73.16(Geochemistry & Geophysics)将来の火山活動は、過去の地質学的データ(火山の位置、噴火年代等)によって予測が試みられているが、データが不足している地域については予測結果に対する信頼性が十分でない。そのため、地震波速度構造や地温勾配分布等の地球物理学的データを基に、ベイズ法によって将来の火山活動を予測する手法の検討を行った。
