論文 - 菱川　明栄

Electronic and nuclear responses of fixed-in-space H2S to ultrashort intense laser fields 査読有り

Akiyoshi Hishikawa, Eiji J. Takahashi, Akitaka Matsuda

PHYSICAL REVIEW LETTERS   97 巻 ( 24 )   2006年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMERICAN PHYSICAL SOC  

The Coulomb explosion dynamics of H2S, H2S3+-> H++S++H+, in ultrashort intense laser fields (12 fs, similar to 2x10(14) W/cm(2)) is studied by the coincidence momentum imaging of the three fragment ions. Different electronic and nuclear responses are identified depending on the direction of laser polarization epsilon in the molecular frame. The dependence can be interpreted in terms of the electronic and bonding characters of charge transfer states of H2S coupled to the electronic ground state.

DOI： 10.1103/PhysRevLett.97.243002

Web of Science

Dissociative ATI of H-2 and D-2 in intense soft x-ray laser fields 査読有り

K Hoshina, A Hishikawa, K Kato, T Sako, K Yamanouchi, EJ Takahashi, Y Nabekawa, K Midorikawa

JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS   39 巻 ( 4 ) 頁： 813 - 829   2006年2月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

The dissociative photoionization processes of H-2 and D-2 in an intense, short-pulsed soft x-ray field (lambda = 29.6 nm, 3 x 10(12) W CM-2, 15 fs) generated as the 27th high-order harmonic of a Ti:sapphire laser is investigated for the first time by time-of-flight mass spectrometry. The ejected H+ fragment ions from H2 are distributed in the kinetic energy range of 3-20 eV peaked at 10.0 eV, and the yield exhibits a nonlinear dependence of the order of 1.7(l) on the light field intensity of the 27th harmonic. Similarly, the D+ fragment ions from D-2 are distributed in the 3-20 eV range peaked at 10.3 eV, and the yield exhibits a nonlinear dependence of the order of 1.6 +/- 0.2. The kinetic energy distributions of H+ and D+ and the nonlinearity in their yields are interpreted well by the two coexisting ionization processes: (i) one-photon dissociative ionization and (ii) dissociative two-photon above-threshold-ionization (ATI) mainly into the repulsive 2p pi(u) state.

DOI： 10.1088/0953-4075/39/4/007

Web of Science

Electronic and nuclear responses of fixed-in-space H2S to ultrashort intense laser fields 査読有り

Hishikawa, A. and Takahashi, E. J. and Matsuda, A.

Physical Review Letters   97 巻 ( 24 ) 頁： 243002   2006年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The Coulomb explosion dynamics of H2S, H2S3+-> H++S++H+, in ultrashort intense laser fields (12 fs, similar to 2x10(14) W/cm(2)) is studied by the coincidence momentum imaging of the three fragment ions. Different electronic and nuclear responses are identified depending on the direction of laser polarization epsilon in the molecular frame. The dependence can be interpreted in terms of the electronic and bonding characters of charge transfer states of H2S coupled to the electronic ground state.

DOI： Doi 10.1103/Physrevlett.97.243002

Dissociative ATI of H-2 and D-2 in intense soft x-ray laser fields 査読有り

Hoshina, K. and Hishikawa, A. and Kato, K. and Sako, T. and Yamanouchi, K. and Takahashi, E. J. and Nabekawa, Y. and Midorikawa, K.

Journal of Physics B-Atomic Molecular and Optical Physics   39 巻 ( 4 ) 頁： 813-829   2006年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The dissociative photoionization processes of H-2 and D-2 in an intense, short-pulsed soft x-ray field (lambda = 29.6 nm, 3 x 10(12) W CM-2, 15 fs) generated as the 27th high-order harmonic of a Ti:sapphire laser is investigated for the first time by time-of-flight mass spectrometry. The ejected H+ fragment ions from H2 are distributed in the kinetic energy range of 3-20 eV peaked at 10.0 eV, and the yield exhibits a nonlinear dependence of the order of 1.7(l) on the light field intensity of the 27th harmonic. Similarly, the D+ fragment ions from D-2 are distributed in the 3-20 eV range peaked at 10.3 eV, and the yield exhibits a nonlinear dependence of the order of 1.6 +/- 0.2. The kinetic energy distributions of H+ and D+ and the nonlinearity in their yields are interpreted well by the two coexisting ionization processes: (i) one-photon dissociative ionization and (ii) dissociative two-photon above-threshold-ionization (ATI) mainly into the repulsive 2p pi(u) state.

Concerted and sequential Coulomb explosion processes of N2O in intense laser fields by coincidence momentum imaging 査読有り

M Ueyama, H Hasegawa, A Hishikawa, K Yamanouchi

JOURNAL OF CHEMICAL PHYSICS   123 巻 ( 15 )   2005年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

The Coulomb explosion dynamics of N2O in intense laser fields (800 nm, 60 fs, similar to 0.16 PW/cm(2)) is studied by the coincidence momentum imaging method. From the momentum correlation maps obtained for the three-body fragmentation pathway, N2O3+-> N++N++O+, the ultrafast structural deformation dynamics of N2O prior to the Coulomb explosion is extracted. It is revealed that the internuclear N-N and N-O distances stretch simultaneously as the bond angle > N-N-O decreases. In addition, two curved thin distributions are identified in the momentum correlation maps, and are interpreted well as those originating from the sequential dissociation pathway, N2O3+-> N++NO2+-> N++N++O+. (c) 2005 American Institute of Physics.

DOI： 10.1063/1.2032988

Web of Science

Probing the ultrafast nuclear motion in CS22+ in intense laser fields 査読有り

A Hishikawa, M Ueyama, K Yamanouchi

JOURNAL OF CHEMICAL PHYSICS   122 巻 ( 15 )   2005年4月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

The temporal evolution of the nuclear wave packet of CS(2)2+ formed in an intense laser field (60 fs, 0.13 PW/cm(2)) is traced in real time by the pump-and-probe technique combined with coincidence momentum imaging of the Coulomb explosion process, CS23+->S+ + C+ + S+. The momentum correlations among the fragment ions obtained as a function of the pump-probe time delay between 133 fs to 3 ps reveal that the nuclear wave packet in CS22+ evolves not only along the anti-symmetric stretching coordinate to yield S+ and CS+ but also along the symmetric stretching coordinate leading to the simultaneous breaking of the two C-S bonds. The contribution from two different electronic states having bent and linear-type geometrical configurations is identified in the wave packet motion along the bending coordinate of CS22+. 2005 American Institute of Physics.

DOI： 10.1063/1.1895745

Web of Science

Probing the ultrafast nuclear motion in CS22+ in intense laser fields 査読有り

Hishikawa, A. and Ueyama, M. and Yamanouchi, K.

Journal of Chemical Physics   122 巻 ( 15 ) 頁： 151104   2005年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The temporal evolution of the nuclear wave packet of CS(2)2+ formed in an intense laser field (60 fs, 0.13 PW/cm(2)) is traced in real time by the pump-and-probe technique combined with coincidence momentum imaging of the Coulomb explosion process, CS23+->S+ + C+ + S+. The momentum correlations among the fragment ions obtained as a function of the pump-probe time delay between 133 fs to 3 ps reveal that the nuclear wave packet in CS22+ evolves not only along the anti-symmetric stretching coordinate to yield S+ and CS+ but also along the symmetric stretching coordinate leading to the simultaneous breaking of the two C-S bonds. The contribution from two different electronic states having bent and linear-type geometrical configurations is identified in the wave packet motion along the bending coordinate of CS22+. 2005 American Institute of Physics.

DOI： Doi 10.1063/1.1895745

Concerted and sequential Coulomb explosion processes of N2O in intense laser fields by coincidence momentum imaging 査読有り

Ueyama, M. and Hasegawa, H. and Hishikawa, A. and Yamanouchi, K.

Journal of Chemical Physics   123 巻 ( 15 ) 頁： 154305   2005年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The Coulomb explosion dynamics of N2O in intense laser fields (800 nm, 60 fs, similar to 0.16 PW/cm(2)) is studied by the coincidence momentum imaging method. From the momentum correlation maps obtained for the three-body fragmentation pathway, N2O3+-> N++N++O+, the ultrafast structural deformation dynamics of N2O prior to the Coulomb explosion is extracted. It is revealed that the internuclear N-N and N-O distances stretch simultaneously as the bond angle > N-N-O decreases. In addition, two curved thin distributions are identified in the momentum correlation maps, and are interpreted well as those originating from the sequential dissociation pathway, N2O3+-> N++NO2+-> N++N++O+. (c) 2005 American Institute of Physics.

DOI： Doi 10.1063/1.2032988

Hydrogen migration in acetonitrile in intense laser fields in competition with two-body Coulomb explosion 査読有り

A Hishikawa, H Hasegawa, K Yamanouchi

JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA   141 巻 ( 2-3 ) 頁： 195 - 200   2004年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Two-body Coulomb explosion processes of acetonitrile (CH3CN) and deuterated acetonitrile (CD3CN), CH3CN2+ --> CH3-n+ +HnCN+ and CD3CN2+ --> CD3-n+ +DnCN+ (n = 0-2), in an intense laser field (0.15 pW/cm(2), 70 fs) are investigated by the coincidence momentum imaging method. The comparable yields derived for the three pathways (n = 0-2) shows that the hydrogen atom migration proceeds in competition with the Coulomb explosion. The angular distributions of the fragment ions for n = 0 exhibits a sharp peak along the laser polarization direction while the angular distribution becomes more isotropic as n increases. Based on a least-squares analysis of the fragment anisotropy, the dissociation lifetimes of the doubly charged acetonitrile were determined, from which the time scale of the hydrogen migration as well as the deformation of the C-C-N skeleton prior to the explosion were discussed. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.elspec.2004.06.009

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Nuclear dynamics on the light-dressed potential energy surface Of CS2 by coincidence momentum imaging 査読有り

A Hishikawa, H Hasegawa, K Yamanouchi

CHEMICAL PHYSICS LETTERS   388 巻 ( 1-3 ) 頁： 1 - 6   2004年4月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

The non-sequential three-body Coulomb explosion, CS23+ --> S+ + C+ + S+, in an intense laser field (0.2 PW/cm(2), 60 fs) is studied by the coincidence momentum imaging of the fragment ions. The observed angular distribution of the momentum vectors of the two S+ ions, p(1) (S+) and p(2)(S+), exhibits a peak at an angle as small as theta(12) similar to 140degrees, showing that the nuclear motion is induced along the bending coordinate to a large extent prior to the explosion. On the other hand, the difference between their absolute values, Deltap(12) = \p(1)(S+)\ - \p(2)(S+), has a sharp distribution peaked at Deltap(12) = 0, suggesting that the symmetric stretching motion dominates over the antisymmetric stretching motion in the laser field. Based on the energy dependence of the momentum vector correlation, the characteristic nuclear dynamics of CS2 on the light-dressed potential energy surfaces in an intense laser field is discussed. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2004.01.128

Web of Science

Hydrogen migration in acetonitrile in intense laser fields in competition with two-body Coulomb explosion 査読有り

Hishikawa, A. and Hasegawa, H. and Yamanouchi, K.

Journal of Electron Spectroscopy and Related Phenomena   141 巻 ( 2-3 ) 頁： 195-200   2004年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Two-body Coulomb explosion processes of acetonitrile (CH3CN) and deuterated acetonitrile (CD3CN), CH3CN2+ --> CH3-n+ +HnCN+ and CD3CN2+ --> CD3-n+ +DnCN+ (n = 0-2), in an intense laser field (0.15 pW/cm(2), 70 fs) are investigated by the coincidence momentum imaging method. The comparable yields derived for the three pathways (n = 0-2) shows that the hydrogen atom migration proceeds in competition with the Coulomb explosion. The angular distributions of the fragment ions for n = 0 exhibits a sharp peak along the laser polarization direction while the angular distribution becomes more isotropic as n increases. Based on a least-squares analysis of the fragment anisotropy, the dissociation lifetimes of the doubly charged acetonitrile were determined, from which the time scale of the hydrogen migration as well as the deformation of the C-C-N skeleton prior to the explosion were discussed. (C) 2004 Elsevier B.V. All rights reserved.

Hydrogen migration in acetonitrile in intense laser fields studied by coincidence momentum imaging 査読有り

Hishikawa, A. and Hasegawa, H. and Yamanouchi, K.

Physica Scripta   T110 巻   頁： 108-111   2004年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The two-body Coulomb explosion of acetonitrile, CH3CN2+ -> CH3-n+ + HnCN+(n = 0-2), in intense laser fields (0.15 PW/cm(2), 70 fs) is studied by the coincidence momentum imaging technique. It is found that the fragment ions for n 0 are ejected mostly in the direction of the laser polarization vector with < cos(2)theta > = 0.68, where theta is the angle between the fragment recoil direction and the laser polarization vector, while the angle distribution becomes more isotropic as n increases, i.e., < cos(2)theta > = 0.49 for n = 1 and < cos(2)theta > = 0.37 for n = 2. From this characteristic correlation between the anisotropy in the fragment ejection and the hydrogen migration, the Coulomb explosion dynamics competing with the hydrogen atom transfer from the methyl group to the nitrile group is investigated.

Nuclear dynamics on the light-dressed potential energy surface of CS2 by coincidence momentum imaging 査読有り

Hishikawa, A. and Hasegawa, H. and Yamanouchi, K.

Chemical Physics Letters   388 巻 ( 1-3 ) 頁： 1-6   2004年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The non-sequential three-body Coulomb explosion, CS23+ --> S+ + C+ + S+, in an intense laser field (0.2 PW/cm(2), 60 fs) is studied by the coincidence momentum imaging of the fragment ions. The observed angular distribution of the momentum vectors of the two S+ ions, p(1) (S+) and p(2)(S+), exhibits a peak at an angle as small as theta(12) similar to 140degrees, showing that the nuclear motion is induced along the bending coordinate to a large extent prior to the explosion. On the other hand, the difference between their absolute values, Deltap(12) = \p(1)(S+)\ - \p(2)(S+), has a sharp distribution peaked at Deltap(12) = 0, suggesting that the symmetric stretching motion dominates over the antisymmetric stretching motion in the laser field. Based on the energy dependence of the momentum vector correlation, the characteristic nuclear dynamics of CS2 on the light-dressed potential energy surfaces in an intense laser field is discussed. (C) 2004 Elsevier B.V. All rights reserved.

Hydrogen migration in acetonitrile in intense laser fields studied by coincidence momentum imaging 査読有り

Akiyoshi Hishikawa, Hirokazu Hasegawa, Kaoru Yamanouchi

PHYSICA SCRIPTA   T110 巻   頁： 108 - 111   2004年

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

The two-body Coulomb explosion of acetonitrile, CH3CN2+ -> CH3-n+ + HnCN+(n = 0-2), in intense laser fields (0.15 PW/cm(2), 70 fs) is studied by the coincidence momentum imaging technique. It is found that the fragment ions for n 0 are ejected mostly in the direction of the laser polarization vector with < cos(2)theta > = 0.68, where theta is the angle between the fragment recoil direction and the laser polarization vector, while the angle distribution becomes more isotropic as n increases, i.e., < cos(2)theta > = 0.49 for n = 1 and < cos(2)theta > = 0.37 for n = 2. From this characteristic correlation between the anisotropy in the fragment ejection and the hydrogen migration, the Coulomb explosion dynamics competing with the hydrogen atom transfer from the methyl group to the nitrile group is investigated.

DOI： 10.1238/Physica.Topical.110a00108

Web of Science

Hydrogen migration in acetonitrile in intense laser fields studied by coincidence momentum imaging 査読有り

Akiyoshi Hishikawa, Hirokazu Hasegawa, Kaoru Yamanouchi

Physica Scripta T   T110 巻   頁： 108 - 111   2004年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The two-body Coulomb explosion of acetonitrile, CH3CN 2+ → CH3-n+ + HnCN+ (n = 0-2), in intense laser fields (0.15 PW/cm2, 70 fs) is studied by the coincidence momentum imaging technique. It is found that the fragment ions for n = 0 are ejected mostly in the direction of the laser polarization vector with 〈 cos2 θ 〉 = 0.68, where θ is the angle between the fragment recoil direction and the laser polarization vector, while the angle distribution becomes more isotropic as n increases, i.e., 〈 cos2 θ 〉 = 0.49 for n = 1 and 〈 cos2 θ 〉 = 0.37 for n = 2. From this characteristic correlation between the anisotropy in the fragment ejection and the hydrogen migration, the Coulomb explosion dynamics competing with the hydrogen atom transfer from the methyl group to the nitrile group is investigated. © Physica Scripta 2004.

DOI： 10.1238/Physica.Topical.110a00108

Scopus

Sequential three-body Coulomb explosion of CS2 in intense laser fields appearing in momentum correlation map 査読有り

A Hishikawa, H Hasegawa, K Yamanouchi

CHEMICAL PHYSICS LETTERS   361 巻 ( 3-4 ) 頁： 245 - 250   2002年7月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

The three-body Coulomb explosion process of CS2 in intense laser fields (60 fs, 0.36 x 10(15) W/cm(2)), CS23+ --&gt; S+ + C+ + S+, is studied by the triple coincidence momentum imaging of the atomic fragment ions. The set of the observed momentum vectors of the fragment ions determined for respective explosion events exhibits a clear trajectory originating from the rotational motion of an intermediate CS2+ ion, formed in a sequential explosion process of CS23+ prior to the complete three-body fragmentation. The contribution of the sequential pathway to the overall three-body explosion process is estimated to be 17(1)%. (C) 2002 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0009-2614(02)00880-1

Web of Science

Suppression of decomposition of aniline cation in intense laser fields by cluster formation with ammonia molecules 査読有り

J Watanabe, R Itakura, A Hishikawa, K Yamanouchi

JOURNAL OF CHEMICAL PHYSICS   116 巻 ( 22 ) 頁： 9697 - 9702   2002年6月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

Mass-selected aniline cations and [aniline-(NH3)(n)](+) (n=1 and 2) cluster ions are exposed to the femtosecond laser fields (lambdasimilar to395 nm,Isimilar to4x10(15) W/cm(2)) and the nanosecond laser fields (lambda=532 nm,Isimilar to2.7x10(10) W/cm(2)) by using a tandem type time-of-flight mass spectrometer. In the case of the bare aniline cation, the decomposition forming the five-membered ring compound, cyclopentadienyl cation (C5H6+), dominantly proceeds in both the femtosecond and nanosecond laser fields. When one or two ammonia molecules are attached to the aniline cation, the decomposition is significantly suppressed. This suppression was interpreted in terms of an intermolecular energy flow through the hydrogen bonding. (C) 2002 American Institute of Physics.

DOI： 10.1063/1.1475753

Web of Science

Coincidence Imaging of coulomb explosion of CS2 in intense laser fields 査読有り

H Hasegawa, K Doi, A Hishikawa, K Yamanouchi

SCIENCE OF SUPERSTRONG FIELD INTERACTIONS   634 巻   頁： 197 - 198   2002年

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：AMER INST PHYSICS  

The coincidence imaging technique is applied to direct determination of the momentum vectors of all the fragment ions produced through every event of the Coulomb explosion of a single molecular ion, CS2+ (z = 2 - 4) formed in intense laser fields (0.36 PW/cm(2)). The molecular structure Of CS23+ just before the three-body Coulomb explosion is reconstructed from the measured momentum vectors of the atomic fragment ions. It was confirmed that the skeletal deformation of CS2 is induced to a large extent in intense laser fields.

Web of Science

Coincidence imaging of Coulomb explosion of CS2 in intense laser fields 査読有り

H Hasegawa, A Hishikawa, K Yamanouchi

CHEMICAL PHYSICS LETTERS   349 巻 ( 1-2 ) 頁： 57 - 63   2001年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

The coincidence imaging technique is applied to direct determination of the momentum vectors of all the fragment ions produced through every event of the Coulomb explosion of a single molecular ion, CS22+ (z = 2-4) formed in intense laser of CS23+ just fields (similar to 60 fs, 0.36 x 10(15) W/cm(2)). The molecular structure I before the Coulomb explosion, CS23+ --&gt; S+ + C+ + S+, is reconstructed from the measured momentum vectors of the fragment ions. The mean C-S bond length of &lt;r &gt; = 2.5 Angstrom and the azimuthally averaged S-C-S bond angle, &lt; gamma &gt; = 145 degrees, thus determined indicate that structural deformation occurs to a large extent in the intense laser fields. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0009-2614(01)01087-9

Web of Science

Real-time probing of alignment and structural deformation of CS2 in intense nanosecond laser fields 査読有り

A Iwasaki, A Hishikawa, K Yamanouchi

CHEMICAL PHYSICS LETTERS   346 巻 ( 5-6 ) 頁： 379 - 386   2001年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

A time evolution of the alignment and structural deformation processes of neutral CS2 in intense non-resonant nanosecond laser fields (1.9 X 10(12) W/cm(2)) is derived by ionizing CS2 using intense circularly polarized feintosecond laser fields (5.5 x 10(14) W/cm(2)). From the real-time probing of the momentum distribution of the resultant S3+ and C2+ fragment ions produced through the Coulomb explosion induced by the intense fenitosecond laser fields, it is identified that the alignment and the structural deformation proceed simultaneously in the nanosecond laser fields. (C) 2001 Elsevier Science BN. All rights reserved.

DOI： 10.1016/S0009-2614(01)00963-0

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