検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 14 件中 1件目~14件目を表示
  • 1

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

Nano-meter size modification of metal surfaces induced by soft X-ray laser single pulse

石野 雅彦; Faenov, A.*; 田中 桃子; Pikuz, T.; 保 智己*; 長谷川 登; 錦野 将元; Starikov, S. V.*; Stegailov, V. V.*; Norman, G.*; et al.

X-Ray Lasers 2012; Springer Proceedings in Physics, Vol.147, p.121 - 124, 2014/00

 被引用回数:0 パーセンタイル:100

We show experimentally the possibility of the precise nano-meter size surface structuring of metal surfaces induced by ultra low fluencies of pico-second soft X-ray laser single pulse. After irradiation processes, we observed the modified surfaces to understand the interactions between the soft X-ray laser pulses and various materials by a scanning electron microscope. The formations of unique modified structures caused by irradiations of the soft X-ray laser pulses were seen. On Al surface, the formations of conical structures were observed in the shallow features. On Au surface, the ripple-like structures were observed. The atomistic model of ablation is developed that reveals the ultra-low threshold fluency values of this process. Calculated ablation depth as a function of irradiation fluency is in good agreement with the experimental data presented as well as with the existing data on optical ablation. Our results will open new opportunities for nano-meter size processing for metal surfaces.

論文

Defect characterization in compositionally graded InGaAs layers on GaAs (001) grown by MBE

佐々木 拓生; Norman, A. G.*; Romero, M. J.*; Al-Jassim, M. M.*; 高橋 正光; 小島 信晃*; 大下 祥雄*; 山口 真史*

Physica Status Solidi (C), 10(11), p.1640 - 1643, 2013/11

 被引用回数:3 パーセンタイル:16.95

Defect characterization in compositionally step graded In$$_{x}$$Ga$$_{1-x}$$As layers with different thickness of the overshooting (OS) layer was performed using cathodoluminescence (CL) and transmission electron microscopy (TEM). We found that the type and in-plane distribution of defects generated in the top InGaAs layer grown on step graded layers strongly depend on the thickness of the OS layer. In the thin OS layer, a high density of threading dislocations aligned along [110] was observed. In the thick OS layer, significant line defects associating composition variation were dominantly present. These features on defect type and distribution would relate to strain and configuration of the OS layer.

論文

Nano-meter scale modifications on material surfaces induced by soft X-ray laser pulse irradiations

石野 雅彦; Faenov, A.*; 田中 桃子; 保 智己*; Pikuz, T.; 長谷川 登; 錦野 将元; Inogamov, N.*; Skobelev, I.*; Fortov, V.*; et al.

Proceedings of SPIE, Vol.8849, p.88490F_1 - 88490F_8, 2013/09

 被引用回数:2 パーセンタイル:20.97

To study the interactions between soft X-ray laser (SXRL) beam and material surfaces, we irradiated the SXRL beam pulses having a wavelength of 13.9 nm and duration of 7 ps to Al, Au, Cu, and Si. Irradiated surfaces were observed using SEM and AFM. With single pulse irradiation, the formation of conical structures was observed on Al, and ripple-like structures were formed on Au and Cu. The conical structures on Al surface were destroyed under the multiple SXRL pulse exposures, but it was confirmed that the development of modified structures was observed after multiple pulse exposures on the Au and Cu surfaces. On the Si surface, deep holes that seemed to be melted structures induced by the accumulation of multiple pulses of irradiations were found. It was concluded that SXRL beam irradiation of various material surfaces causes different types of surface modifications, and the changes in the surface behaviors are attributed to the differences in the elemental properties, such as the melting points and the attenuation length of X-ray photons.

論文

Determining the $$^{239}$$Np($$n$$,$$f$$) cross section using the surrogate ratio method

Czeszumska, A.*; Angell, C.; Burke, J. T.*; Scielzo, N. D.*; Norman, E. B.*; Austin, R. A. E.*; Boutoux, G.*; Casperson, R. J.*; Chodash, P.*; Hughes, R. O.*; et al.

Physical Review C, 87(3), p.034613_1 - 034613_6, 2013/03

AA2012-0918.pdf:0.85MB

 被引用回数:11 パーセンタイル:33.76(Physics, Nuclear)

Neutron-induced fission cross section data are needed in various fields of applied and basic nuclear science. However, cross sections of short-lived nuclei are difficult to measure directly due to experimental constraints. The first experimental determination of the neutron-induced fission cross section of $$^{239}$$Np at non-thermal energies was performed. The Surrogate Ratio Method (SRM) was employed to indirectly deduce the $$^{239}$$Np($$n$$,$$f$$) cross section. The surrogate reactions used were $$^{236}$$U$$(rm ^3He,p)$$ and $$^{238}$$U$$(rm ^3He,p)$$ with the reference cross section given by the well-known $$^{239}$$Np($$n$$,$$f$$) cross section. The ratio of observed fission reactions resulting from the two formed compound nuclei, $$^{238}$$Np and $$^{240}$$Np, was multiplied by the directly-measured $$^{237}$$Np($$n$$,$$f$$) cross section to determine the$$^{239}$$Np($$n$$,$$f$$) cross section. The $$^{239}$$Np($$n$$,$$f$$) cross section was determined with an uncertainty ranging between 3 - 30% over the energy range of 0.2 - 20 MeV.

論文

Nanomodification of gold surface by picosecond soft X-ray laser pulse

Norman, G.*; Starikov, S.*; Stegailov, V.*; Fortov, V.*; Skobelev, I.*; Pikuz, T.; Faenov, A.*; 保 智己*; 加藤 義章*; 石野 雅彦; et al.

Journal of Applied Physics, 112(1), p.013104_1 - 013104_8, 2012/07

 被引用回数:35 パーセンタイル:15.91(Physics, Applied)

It was shown experimentally the possibility of nanostructuring (about 20 nm) of gold surface by picosecond soft X-ray single pulse with low fluence of 20 mJ/cm$$^{2}$$. The nanometer-scale changes of the surface structure are due to the splash of molten gold under fluence gradient of the laser beam. In addition, the ablation process occurs at slightly higher fluence of 50 mJ/cm$$^{2}$$. The atomistic model of ablation is developed that reveals that the low threshold fluence of this process is due to the build-up of the high electron pressure and the comparatively low electron-ion energy relaxation rate in gold.

論文

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:22 パーセンタイル:29.37(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。

論文

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:142 パーセンタイル:0.63(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。

論文

Laser ablation of gold; Experiment and atomistic simulation

Starikov, S. V.*; Stegailov, V. V.*; Norman, G. E.*; Fortov, V. E.*; 石野 雅彦; 田中 桃子; 長谷川 登; 錦野 将元; 大場 俊幸*; 海堀 岳史; et al.

JETP Letters, 93(11), p.642 - 647, 2011/04

 被引用回数:23 パーセンタイル:22.34(Physics, Multidisciplinary)

The interaction of radiation of a picosecond X-ray laser (wavelength $$lambda$$ = 13.9 nm) with targets made of a thick gold film has been studied theoretically and experimentally. It has been shown experimentally that the action of individual X-ray laser pulses with a fluence of $$F$$ $${approx}$$ 21 mJ/cm$$^{2}$$ initiates the nanostructuring of the gold surface. Explicitly taking into account the electron subsystem, we have proposed an atomistic model of ablation that makes it possible to adequately described the experimental results. The atomistic simulation involves the ion-ion potential depending on the electron temperature $$T$$$$_{e}$$. The use of such a potential makes it possible to take into account an increase in the pressure in the system with increasing $$T$$$$_{e}$$ and to reveal two laser ablation mechanisms.

論文

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:137 パーセンタイル:1.54(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。

口頭

Soft X-ray laser single picosecond pulse nanomodification of metal surfaces

Pikuz, T.; Faenov, A.*; 石野 雅彦; Starikov, S. V.*; Stegailov, V. V.*; Norman, G.*; Fortov, V.*; Skobelev, I.*; 保 智己*; 加藤 義章*; et al.

no journal, , 

We show experimentally the possibility of the precise nanostructuring of aluminum and gold surfaces by ultra low fluencies of single picosecond soft X-ray laser pulse. The atomistic model of ablation is developed that reveals the ultra-low threshold fluency values of this process to be an effect of the high electronic pressure build-up and the comparatively low electron-ion energy relaxation rates. Our modeling show that relatively slow electron-ionic relaxation in such metals results in maintaining of the high electron pressure in the near surface region for several picoseconds, that is sufficiently long for the development of the hydrodynamic response that causes the negative pressure region formation and the nanostructuring of a thin surface layer. Calculated ablation depth as a function of irradiation fluency is in good agreement with the experimental data presented as well as with the existing data on optical ablation.

口頭

プラズマX線レーザーの発生と物質アブレーション

錦野 将元; 石野 雅彦; Faenov, A.*; 田中 桃子; Pikuz, T.; Starikov, S. V.*; Vladimir, V.*; Norman, G.*; Fortov, V.*; Skobelev, I.*; et al.

no journal, , 

近年、軟X線から硬X線領域における加速器ベースのX線自由電子レーザー開発が国内外で急速に進展している。プラズマ軟X線レーザーでは通常のレーザーと同様に特定の準位間で反転分布を生成することでコヒーレント光を発生する。このようなコヒーレントX線源開発研究において時間的にも空間的にも高コヒーレンスで繰り返し発生が可能な軟X線レーザーが開発され、応用研究が開始されている。軟X線は可視光よりも高密度プラズマに対する透過力が高いことから、プラズマ研究用のプローブ光源としての利用が主な用途であったが、近年では、可視光よりも波長が短く、かつ硬X線よりも物質に対する浸入深さが小さいという特徴を活かして、物質表面の精密計測の光源として利用されるようになり、また軟X線レーザーによる微細加工に関して、アルミニウムや金等の金属表面に軟X線レーザーを照射し、X線レーザーアブレーションによって生成される表面微細構造研究を展開している。軟X線レーザーアブレーション生成や生成されたナノメートルスケールの微細構造について講演を行う。また、同様に軟X線レーザーを生物細胞に照射したときに生じる放射線生物影響についても述べる。

口頭

Splash-melting nano-meter size modification of metal surfaces induced by soft X-ray laser single pulse

石野 雅彦; Faenov, A. Ya.*; 田中 桃子; Pikuz, T.; 保 智己*; 長谷川 登; 錦野 将元; Starikov, S. V.*; Stegailov, V. V.*; Norman, G. E.*; et al.

no journal, , 

Laser ablation has many technological applications in material micro-meter size processing and fabrication of nano-structures. We show experimentally the possibility of the precise nano-meter size surface structuring of metal aluminum (Al) and gold (Au) surfaces induced by ultra low fluencies of pico-second soft X-ray laser (SXRL) single pulse. The spatially coherent SXRL beam was generated from the silver (Ag) plasma mediums using oscillator-amplifier configuration with Ag double targets. The generated SXRL pulse had the wavelength of 13.9 nm and the duration of 7 ps. On Al surface, the formations of conical structures were observed in the shallow features. On Au surface, the ripple-like structures were observed. The atomistic model of surface modifications is developed that reveals the ultra-low threshold fluency values of this process and suggests it as a splash-melting regime. Our results will open new opportunities for nano-meter size processing for metal surfaces.

口頭

Metal surfaces nanomodifications induced by the single and multiple pulse soft X-ray laser beam irradiations

Faenov, A.*; Pikuz, T.; 石野 雅彦; Starikov, S. V.*; Stegailov, V. V.*; Norman, G.*; Fortov, V. E.*; Skobelev, I. Yu.*; 保 智己*; 田中 桃子; et al.

no journal, , 

A systematic experimental study of the surface modifications resulting from the interactions of both single and multiple SXRL pulses in order to confirm the development of the modified structures during multiple shots irradiation. The interactions between single or multiple picosecond soft X-ray laser (SXRL) beam and metal (such as gold (Au), copper (Cu), and aluminum (Al)) surfaces, were investigated. Our results demonstrate that tensile stress created in metals by short X-ray pulse can produce spallative ablation of target even for drastically small X-ray fluencies, which open new opportunities for material nano processing.

口頭

Low-threshold surface modification of metals irradiated by picosecond soft X-ray laser pulses; Observation and modeling

Pikuz, T.; Faenov, A.*; 石野 雅彦; Starikov, S. V.*; Stegailov, V. V.*; Norman, G. E.*; Fortov, V.*; Skobelev, I.*; Inogamov, N. A.*; Zhakhovsky, V. V.*; et al.

no journal, , 

Systematic experimental and theoretical studies of the surface modifications resulting from the interactions of both single and multiple SXRL pulses irradiation of metals have been provided. Developed models show that relatively slow electron-ionic relaxation in such metals results in maintaining of the high electron pressure in the near surface region for several picoseconds, that is sufficiently long for the development of the hydrodynamic response that causes the negative pressure region formation and the nanostructuring of a thin surface layer. Obtained results demonstrate that tensile stress created in metals by short X-ray pulse can produce spallative ablation of target even for drastically small X-ray fluencies, which open new opportunities for material nano processing.

14 件中 1件目~14件目を表示
  • 1