巻号一覧
35 巻, 11 号
選択された号の論文の9件中1～9を表示しています
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強光子場科学研究の現状と将来展望山内 薫2007 年 35 巻 11 号 p. 680-684
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーRecent development of high-power ultrashort-pulsed laser technologies has made it possible to increase the light field intensity as high as the magnitude of a Coulombic field within atoms and molecules, and afforded the basis of the birth of the new interdisciplinary research field called “Intense Laser Science.” It has become possible to control molecular processes by intense laser fields, and a new research area of “Attochemistr” is about to emerge.抄録全体を表示PDF形式でダウンロード (1397K) -
中島 信昭2007 年 35 巻 11 号 p. 685-690
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーIonization of organic molecules irradiated with intense infrared femtosecond pulses is explained from the perspective of intact molecular ion formation. Among the excitation parameters affecting ionization and fragmentation processes, excitation pulse durations and excitation wavelengths at a fixed laser intensity have been found to drastically change fragmentation patterns. An ultimately short pulse presumably leads to the formation of fragment-free ions. Those ions are produced when the wavelengths are non-resonant with the electronic levels of the cations. Time-of-flight spectra of femtosecond pulse ionization of cyclohexadiene isomers, 2, 3-dimethyl-1, 3-butadiene, naphthalene, anthracene, and dioxin are presented. Short comments on Coulomb explosion of organic molecules are given. The research subjects of “Reaction in Laser Light Fields Control” in the project of “Control of Molecules in Intense Laser Fields” are briefly reviewed from a point of laser control of chemical reactions.抄録全体を表示PDF形式でダウンロード (1110K) -
河野 裕彦, 中井 克典, 佐藤 幸男2007 年 35 巻 11 号 p. 691-696
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーWe developed a time-dependent (TD) adiabatic state approach to investigate the electronic and nuclear dynamics of molecules in intense laser fields. We applied the approach to reveal the mechanism of the selective dissociation of C-O and C-C bonds of ethanol by intense near-infrared (IR) laser pulses. The results indicate that field-induced nonadiabatic transition plays a decisive role in the reaction of molecules in intense laser fields. We also investigated the stability of highly charged C60 cations produced with an ultrashort near-IR pulse. The effects of nonlinear interactions with pulses are taken into account by combining classical molecular dynamics with the TD adiabatic state approach. The results indicate that large-amplitude vibration with energy of>30 eV is induced in the delocalized hg (1)-like mode of C60 or Cz+60. The vibrational energy deposited and mode selectivity can be controlled by a pulse train, i. e., by changing the intervals between pulses.抄録全体を表示PDF形式でダウンロード (1352K) -
緑川 克美, 清水 俊彦, 沖野 友哉, 山内 薫, 鍋川 康夫2007 年 35 巻 11 号 p. 697-704
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーWe review nonlinear multiphoton processes induced by intense attosecond XUV pulses. Phase-matched high harmonics by a loosely focusing geometry produce high focused intensity sufficient to induce nonlinear optical phenomena in the XUV region. Such nonlinear phenomena not only have been attracting much attention in the field of quantum electronics, but also are of great importance for direct measurement of temporal shapes of the XUV pulses. Nonresonant two photon processes in atoms and molecules in the XUV region are employed for the direct observation of a train of attosecond pulses by means of autocorrelation. A train of attosecond pulses is characterized by energy-resolved autocorrelation with photoelectrons produced by two-photon above threshold ionization in Ar. Molecular Coulomb explosion induced by two-photon double in N2 is demonstrated for the first time and also is found to be useful for efficient measuring a train of attosecond pulses抄録全体を表示PDF形式でダウンロード (5187K) -
中村 一隆2007 年 35 巻 11 号 p. 705-709
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーQuantum emission is high-energy and short pulsed beam of electrons, ions and photons (x-rays) generated by interaction between intense femtosecond laser field and matter. This article review recent research activities on generation of quantum emission and its application to dynamics research in material sciences.抄録全体を表示PDF形式でダウンロード (8312K) -
矢澤 洋紀, 神成 文彦, 板倉 隆二, 山内 薫2007 年 35 巻 11 号 p. 710-719
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーUnder the intense laser-field (>1012W/cm2), the structure of the potential energy surface of the molecule is modified and thus, the time evolution of the vibrational nuclear wave packet could be manipulated by the carrier frequency, amplitude or phase of the excitation laser pulse. In this paper, we describe how the pulse shaping of intense ultrashort laser pulses affects dissociative ionization reaction of ethanol molecules. Influence of the laser pulsewidth on the non-adiabatic transition is clearly demonstrated. Moreover, the dynamics of vibrational nuclear wavepacket generated with intense femtosecond laser pulse in repulsive potential curves is monitored via Coulomb explosion induced by delayed probe laser pulses.抄録全体を表示PDF形式でダウンロード (5142K) -
小栗 克弥, 岡野 泰彬, 西川 正, 中野 秀俊2007 年 35 巻 11 号 p. 720-727
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーWe investigated the spatiotemporal evolution of the expanding femtosecond laser ablation plume of Al with the ultrafast XAFS spectroscopy system that consists of a femtosecond laser plasma source and a Kirkpatrick-Baez (K-B) microscope. We successfully assigned the ejected ablation particles based on the measured absorption spectrum structures near the Ln, llt absorption edge of Al, and clarified the spatial distribution of Al+ions, Al atoms, and liquid Al fine particles in the plume. We also investigated a temperature evolution of the liquid aluminum particles during the expansion of the plume based on an analysis of the slope of the L absorption edge. This suggests that the emitted Al particles travel in a vacuum as a liquid phase with a temperature of about 2500 to 4200 K. These results demonstrate the potential of our system for investigating ultrafast dynamics of femtosecond laser ablatio抄録全体を表示PDF形式でダウンロード (11834K) -
Demonstrated by Ultrasonic Simulation Using Finite Dif6erence MethodYoshihiro YAMASHITA2007 年 35 巻 11 号 p. 728-734
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーMany of Japan's social infrastructure facilities are now entering the latter half of their lifetime. In such circumstances, time- and cost-effective in-situ inspection for SCC (Surface Corrosion Cracking) is required urgently even in the power generation plant market. Optical full-field inspection using pulsed electric speckle pattern interferometry (ESPI) realizes time-effective flaw-screening inspection and will be suitable for RBM (Risk Based Maintenance). Full-field inspection using pulsed ESPI was experimentally demonstrated and simulation results using finite difference method determined attractive performance points.抄録全体を表示PDF形式でダウンロード (7982K) -
Prediction of Holmium-Yttrium-Aluminum-Garnet (Ho: YAG) Laser-Induced Bubble Dynamics in Whole BloodEriko NAKATANI, Takehiro IWASAKI, Tsunenori ARAI2007 年 35 巻 11 号 p. 735-739
発行日: 2007/11/15
公開日: 2014/03/26
ジャーナル フリーOur purpose was to comprehend holmium-yttrium-aluminum-garnet (Ho: YAG) laser-induced bubble dynamics in whole blood. We observed the bubble dynamics in the thin chamber filled with whole blood and water under Ho: YAG laser radiation ranging in energy from 460-680 mJ/pulse via a 400 μm core diameter optical fiber. We also observed the bubble in large water chamber to compare the bubble dynamic behavior between the thin chamber and free space using water. The bubble volume and lifetime generated in the thin blood chamber were 1.03 to 1.25 times larger and 1.2 times longer than in the thin water chamber, respectively. It was estimated that the bubble volume and lifetime in blood free space would be 10.1-22.0 mm3 and 630 μs, respectively. The measured peak collapse pressure in blood free space was 29-37 % of that in water free space. We think our predicted behavior of the bubble in blood may be suitable for blood replacement applications.抄録全体を表示PDF形式でダウンロード (4892K)
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