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Activation and control of visible single defects in 4H-, 6H-, and 3C-SiC by oxidation

Lohrmann, A.*; Castelletto, S.*; Klein, J. R.*; 大島 武; Bosi, M.*; Negri, M.*; Lau, D. W. M.*; Gibson, B. C.*; Prawer, S.*; McCallum, J. C.*; et al.

Applied Physics Letters, 108(2), p.021107_1 - 021107_4, 2016/01

 被引用回数:26 パーセンタイル:81.53(Physics, Applied)

Creation and characterisation of single photon emitters near the surface of 4H- and 6H-silicon carbide bulk substrates and 3C-SiC epitaxially grown on silicon substrates were investigated. These single photon emitters can be created and stabilized by thermal annealing in an oxygen atmosphere at temperatures above 550 $$^{circ}$$C. Hydrofluoric acid (HF) treatment is shown to effectively annihilate the emission from defects and to restore an optically clean surface. However, the emission from the defects can be obtained after re-oxidation above 550 $$^{circ}$$C. By measuring using standard confocal microscopy techniques, the excited state lifetimes for the emitters are found to be in the nanosecond regime in all three polytypes, and the emission dipoles are aligned with the lattice.


Single-photon emitting diode in silicon carbide

Lohrmann, A.*; 岩本 直也*; Bodrog, Z.*; Castelletto, S.*; 大島 武; Karle, T. J.*; Gali, A.*; Prawer, S.*; McCallum, J. C.*; Johnson, B. C.*

Nature Communications (Internet), 6, p.7783_1 - 7783_7, 2015/07

 被引用回数:110 パーセンタイル:96.86(Multidisciplinary Sciences)

A new single photon source (SPS) was found in hexagonal silicon carbide (SiC), and the luminescence from the SPS could be controlled by the operation of the pn diode. The SPS showed electro-luminescence (EL) with spectra between 700 and 850 nm (zero phonon line: 745 nm) and the EL could be easily observed at even room temperature (RT). Also, the SPS has very high thermal stability and can be observed even after 1800 $$^{circ}$$C annealing. The luminescence from the SPS was also observed by photo-luminescence measurements at RT. From Ab initio calculation, it was proposed that the silicon antisite defects beneath cubic SiC inclusion are a reasonable structure for the SPS although the identification of the SPS has not yet done.


Room temperature quantum emission from cubic silicon carbide nanoparticles

Castelletto, S.*; Johnson, B. C.*; Zachreson, C.*; Beke, D.*; Balogh, I.*; 大島 武; Aharonovich, I.*; Gali, A.*

ACS Nano, 8(8), p.7938 - 7947, 2014/08

Single Photon Sources (SPSs) in cubic (3C) Silicon Carbide (SiC) Nano Particles (NPs) were investigated. As a result, photo luminescence (PL) with broad emission at wavelength ranges between 600 and 800 nm was observed from 3C-SiC NPs at room temperature. The second order photon auto-correlation measurements revealed that defect with the PL characteristic is SPSs. The intensity and stability of the PL increased when samples were irradiated with electrons and subsequently annealed at 500 $$^{circ}$$C. From PL measurements at low temperature and theoretical analysis using spin-polarized density functional theory, the defect can be identified as carbon-antisite carbon-vacancy pair (C$$_{Si}$$V$$_{C}$$).


A Silicon carbide room-temperature single-photon source

Castelletto, S.*; Johnson, B.*; Ivady, V.*; Stavrias, N.*; 梅田 享英*; Gali, A.*; 大島 武

Nature Materials, 13(2), p.151 - 156, 2014/02

 被引用回数:312 パーセンタイル:99.38(Chemistry, Physical)

単一フォトンの発生や検出は量子力学の実験的な基盤や計測理論に重要な役割を示す。また、効率的、高品質の単一発光源は量子情報等の実現にとって不可欠と考えられている。本研究では、室温においても非常に明るく安定な炭化ケイ素(SiC)中の単一発光源の形成と同定に成功した。この単一発光源はSiC中のシリコンサイトを炭素で置換した炭素アンチサイト(C$$_{Si}$$)と炭素空孔(V$$_{C}$$)の複合欠陥(C$$_{Si}$$V$$_{C}$$)として知られる点欠陥であり、高純度SiCに対して、電子線照射と照射後の熱処理を組み合わせることで形成が可能となる。非常に明るい光源(2$$times$$10$$^{6}$$ counts/s)であり、キャビティーの使用が無い場合においても高い量子効率が得られる。


Detection of atomic spin labels in a lipid bilayer using a single-spin nanodiamond probe

Kaufmann, S.*; Simpson, D. A.*; Hall, L. T.*; Perunicic, V.*; Senn, P.*; Steinert, S.*; McGuinness, L. P.*; Johnson, B. C.*; 大島 武; Caruso, F.*; et al.

Proceedings of the National Academy of Sciences of the United States of America, 110(27), p.10894 - 10898, 2013/07

 被引用回数:81 パーセンタイル:92.61(Multidisciplinary Sciences)

The detection of gadolinium (Gd) spin labels in an artificial cell membrane under ambient conditions was demonstrated using a single-spin nanodiamond sensor which is negatively charged nitrogen vacancy centers in nanodiamond. Changes in the spin relaxation time (T1) of the sensor located in the lipid bilayer were optically detected using a confocal microscope system. As a result, T1 decreased with increasing proximal Gd labels. The detection of such small numbers of spins in a model biological setting opens a new pathway for in-situ nanoscale detection of dynamical processes in biology.


ISSCREM: International Space Station Cosmic Radiation Exposure Model

El-Jaby, S.*; Lewis, B. J.*; Tomi, L.*; Sihver, L.*; 佐藤 達彦; Lee, K. T.*; Johnson, A. S.*

Proceedings of IEEE Aerospace Conference 2013 (Internet), 18 Pages, 2013/03



ENDF/B-VII.1 nuclear data for science and technology; Cross sections, covariances, fission product yields and decay data

Chadwick, M. B.*; Herman, M.*; Oblo$v{z}$insk$'y$, P.*; Dunn, M. E.*; Danon, Y.*; Kahler, A. C.*; Smith, D. L.*; Pritychenko, B.*; Arbanas, G.*; Arcilla, R.*; et al.

Nuclear Data Sheets, 112(12), p.2887 - 2996, 2011/12

 被引用回数:1623 パーセンタイル:100(Physics, Nuclear)



Plasma boundary and first-wall diagnostics in ITER

Pitcher, C. S.*; Andrew, P.*; Barnsley, R.*; Bertalot, L.*; Counsell, G. G.*; Encheva, A.*; Feder, R. E.*; 波多江 仰紀; Johnson, D. W.*; Kim, J.*; et al.

Journal of Nuclear Materials, 415(Suppl.1), p.S1127 - S1132, 2011/08

 被引用回数:0 パーセンタイル:0.01(Materials Science, Multidisciplinary)

ITER plasma boundary and first-wall diagnostics are summarized in terms of their physical implementation and physics motivation. The challenge of extracting diagnostic signals while maintaining nuclear shielding is discussed, as well as the problems associated with high levels of erosion and redeposition.


Event structure and double helicity asymmetry in jet production from polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07

 被引用回数:25 パーセンタイル:72.31(Astronomy & Astrophysics)

重心エネルギー200GeVでの縦偏極陽子陽子衝突からのジェット生成のイベント構造と二重非対称($$A_{LL}$$)について報告する。光子と荷電粒子がPHENIX実験で測定され、イベント構造がPHYTIAイベント生成コードの結果と比較された。再構成されたジェットの生成率は2次までの摂動QCDの計算で十分再現される。測定された$$A_{LL}$$は、一番低い横運動量で-0.0014$$pm$$0.0037、一番高い横運動量で-0.0181$$pm$$0.0282であった。この$$A_{LL}$$の結果を幾つかの$$Delta G(x)$$の分布を仮定した理論予想と比較する。


Identified charged hadron production in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; 秋葉 康之*; Al-Bataineh, H.*; Alexander, J.*; 青木 和也*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

 被引用回数:156 パーセンタイル:99.42(Physics, Nuclear)

200GeVと62.4GeVでの陽子陽子の中心衝突からの$$pi, K, p$$の横運動量分布及び収量をRHICのPHENIX実験によって測定した。それぞれエネルギーでの逆スロープパラメーター、平均横運動量及び単位rapidityあたりの収量を求め、異なるエネルギーでの他の測定結果と比較する。また$$m_T$$$$x_T$$スケーリングのようなスケーリングについて示して陽子陽子衝突における粒子生成メカニズムについて議論する。さらに測定したスペクトルを二次の摂動QCDの計算と比較する。


Azimuthal correlations of electrons from heavy-flavor decay with hadrons in $$p+p$$ and Au+Au collisions at $$sqrt{s_{NN}}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; 秋葉 康之*; Al-Bataineh, H.*; Alexander, J.*; 青木 和也*; Aphecetche, L.*; Aramaki, Y.*; et al.

Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04

 被引用回数:8 パーセンタイル:52.71(Physics, Nuclear)



Measurement of neutral mesons in $$p$$ + $$p$$ collisions at $$sqrt{s}$$ = 200 GeV and scaling properties of hadron production

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03

 被引用回数:149 パーセンタイル:98.49(Astronomy & Astrophysics)

RHIC-PHENIX実験で重心エネルギー200GeVの陽子陽子衝突からの$$K^0_s$$, $$omega$$, $$eta'$$$$phi$$中間子生成の微分断面積を測定した。これらハドロンの横運動量分布のスペクトルの形はたった二つのパラメーター、$$n, T$$、のTsallis分布関数でよく記述できる。これらのパラメーターはそれぞれ高い横運動量と低い横運動量の領域のスペクトルを決めている。これらの分布をフィットして得られた積分された不変断面積はこれまで測定されたデータ及び統計モデルの予言と一致している。


Overview of high priority ITER diagnostic systems status

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.


Defining the infrared systems for ITER

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:23 パーセンタイル:71.53(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.


Effects of ripple-induced ion thermal transport on H-mode plasma performance

L$"o$nnroth, J.-S.*; Parail, V.*; Hyn$"o$nen, V.*; Johnson, T.*; Kiviniemi, T.*; 大山 直幸; Beurskens, M.*; Howell, D.*; Saibene, G.*; de Vries, P.*; et al.

Plasma Physics and Controlled Fusion, 49(3), p.273 - 295, 2007/03

 被引用回数:14 パーセンタイル:45.66(Physics, Fluids & Plasmas)



In-plant Measurements of Gamma-ray Transmissions for Precise K-edge and Passive Assay of Plutonium Concentration and Isotopic Fractions in Product Solutions

Russo, P. A.*; Hsue, S. T.*; Sprinkle, J. K. Jr.*; Johnson, S. S.*; 朝倉 祥郎*; 近藤 勲*; 舛井 仁一*; 庄司 和弘*

PNC TN841 82-10, 76 Pages, 1982/08




Results of the variable toroidal field ripple experiments in JET

Saibene, G.*; McDonald, D. C.*; Beurskens, M.*; Salmi, A.*; Lonnroth, J. S.*; Parail, V.*; de Vries, P.*; Andrew, Y.*; Budny, R.*; Boboc, A.*; et al.

no journal, , 

本発表は0.08%から約1%までトロイダル磁場リップルの振幅を変化できるJETにおけるリップル実験の結果を報告するものである。リップルがペデスタルとコアプラズマに与える影響をq$$_{95}$$=3$$sim$$3.6のELMy Hモードプラズマで測定した。Hモード特性の変化は明確であるが、閉じ込め性能が劣化する物理機構は明確でない。プラズマ密度の減少や閉じ込め性能劣化は0.5%程度のリップルで観測されるが、その閾値はプラズマパラメータで変化する。リップルはペデスタル圧力とELMにも影響を与える。また、プラズマ回転もリップルの影響を強く受ける。



大島 武; Johnson, B. C.*; Castelletto, S.*; Ivady, V.*; Stavrias, N.*; 梅田 享英*; Gali, A.*

no journal, , 




大島 武; 小野田 忍; 牧野 高紘; 岩本 直也*; Johnson, B. C.*; Lohrmann, A.*; Karle, T.*; McCallum, J. C.*; Castelletto, S.*; 梅田 享英*; et al.

no journal, , 

固体中の単一発光源(SPS)の有するスピンや発光を制御することで、量子コンピューティングやフォトニクスを実現しようという試みが行われている。本研究ではSiCを母材としたSPSの探索を行った。半絶縁性(SI)六方晶(4H)SiC基板に室温にて2MeVのエネルギーの電子線照射後、Ar中、30分間の熱処理を行った。室温又は低温におけるフォトルミネッセンス(PL)測定及び室温における共焦点蛍光顕微鏡(CFM)を用いたアンチバンチング測定によりSPSを探索した。1$$times$$10$$^{17}$$/cm$$^{2}$$の電子線照射後に300$$^{circ}$$Cで熱処理を行った試料に対して80KでのPL測定を行ったところ、850$$sim$$950nm付近にSi空孔が起因のVラインと呼ばれるPL発光が、650$$sim$$700nm付近にC$$_{Si}$$V$$_{C}$$起因のABラインと呼ばれる二種類のPL発光が観測された。ABラインの発光を有する欠陥中心に対して、CFMを用いて室温でアンチバンチグ測定を行った結果、C$$_{Si}$$V$$_{C}$$が単一発光源であることが判明した。また、これまでSteedsらによりABラインは中性のC$$_{Si}$$V$$_{C}$$と主張されていたが、ab initio計算から、この波長領域にPL発光を持つためには正に帯電しているC$$_{Si}$$V$$_{C}$$であるという結果を得た。



大島 武; Lohrmann, A.*; Johnson, B. C.*; Castelletto, S.*; 小野田 忍; 牧野 高紘; 武山 昭憲; Klein, J. R.*; Bosi, M.*; Negri, M.*; et al.

no journal, , 



Visible range photoluminescence from single photon sources in 3C, 4H and 6H silicon carbide

Lohrmann, A.*; Castelletto, S.*; Klein, J. R.*; Bosi, M.*; Negri, M.*; Lau, D. W. M.*; Gibson, B. C.*; Prawer, S.*; McCallum, J. C.*; 大島 武; et al.

no journal, , 

The single photon sources (SPSs) in the visible spectral region were fabricated near the surface of semi-insulating (SI) 4H-silicon carbide (SiC), SI 6H-SiC substrates and 3C-SiC epitaxial films by annealing in dry oxygen. The photoluminescence (PL) with high intensity was observed from samples after oxygen annealing above 550 $$^{circ}$$C although blinking characteristics of PL were observed from samples annealed below 550 $$^{circ}$$C. Also, the samples annealed above 550 $$^{circ}$$C showed blinking characteristics after removing oxygen atoms terminating the surface by HF-etching. Therefore, we can conclude that the oxygen termination is important to obtain stable PL characteristics from the SPSs near the surface of SiC.

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