Faculty Profiles - HISHIKAWA, Akiyoshi

Papers - HISHIKAWA, Akiyoshi

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Visualizing hydrogen atoms migrating in acetylene dication by time-resolved three-body and four-body Coulomb explosion imaging Reviewed

Akitaka Matsuda, Mizuho Fushitani, Eiji J. Takahashi, Akiyoshi Hishikawa

PHYSICAL CHEMISTRY CHEMICAL PHYSICS Vol. 13 ( 19 ) page： 8697 - 8704 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

The visualization of ultrafast isomerization of deuterated acetylene dication (C2D22+) is demonstrated by time-resolved Coulomb explosion imaging with sub-10 fs intense laser pulses ( 9 fs, 0.13 PW cm(-2), 800 nm). The Coulomb explosion imaging monitoring the three-body explosion process, C2D23+ -> D+ + C+ + CD+, as a function of the delay between the pump and probe pulses revealed that the migration of a deuterium atom proceeds in a recurrent manner; One of the deuterium atoms first shifts from one carbon site to the other in a short timescale (similar to 90 fs), and then migrates back to the original carbon site by 280 fs, in competition with the molecular dissociation. Correlated motion of the two deuterium atoms associated with the hydrogen migration and structural deformation to non-planar geometry are identified by the time-resolved four-body Coulomb explosion imaging, C2D24+ - D+ + C+ + C+ + D+.

DOI： 10.1039/c0cp02333g

Web of Science

Scopus

PubMed

EUV SASE-FELを用いた原子の多光子多重イオン化過程の研究 Invited Reviewed

彦坂泰正, 伏谷瑞穂, 菱川明栄

放射光 Vol. 23 ( 5 ) page： 291-294 2010.9

Multiphoton Double Ionization of Ar in Intense Extreme Ultraviolet Laser Fields Studied by Shot-by-Shot Photoelectron Spectroscopy Reviewed

Y. Hikosaka, M. Fushitani, A. Matsuda, C-M. Tseng, A. Hishikawa, E. Shigemasa, M. Nagasono, K. Tono, T. Togashi, H. Ohashi, H. Kimura, Y. Senba, M. Yabashi, T. Ishikawa

PHYSICAL REVIEW LETTERS Vol. 105 ( 13 ) 2010.9

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSICAL SOC

Photoelectron spectroscopy has been performed to study the multiphoton double ionization of Ar in an intense extreme ultraviolet laser field (h nu similar to 21 eV, similar to 5 TW/cm(2)), by using a free electron laser (FEL). Three distinct peaks identified in the observed photoelectron spectra clearly show that the double ionization proceeds sequentially via the formation of Ar(+): Ar + h nu -> Ar(+) + e(-) and Ar(+) + 2h nu -> Ar(2+) + e(-). Shot-by-shot recording of the photoelectron spectra allows simultaneous monitoring of FEL spectrum and the multiphoton process for each FEL pulse, revealing that the two-photon ionization from Ar(+) is significantly enhanced by intermediate resonances in Ar(+).

DOI： 10.1103/PhysRevLett.105.133001

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Scopus

PubMed

Multiphoton Double Ionization of Ar in Intense Extreme Ultraviolet Laser Fields Studied by Shot-by-Shot Photoelectron Spectroscopy Reviewed

Hikosaka, Y. and Fushitani, M. and Matsuda, A. and Tseng, C. M. and Hishikawa, A. and Shigemasa, E. and Nagasono, M. and Tono, K. and Togashi, T. and Ohashi, H. and Kimura, H. and Senba, Y. and Yabashi, M. and Ishikawa, T.

Physical Review Letters Vol. 105 ( 13 ) page： 133001 2010

Language：English Publishing type：Research paper (scientific journal)

DOI： Doi 10.1103/Physrevlett.105.133001

Multiple Explosion Pathways of the Deuterated Benzene Trication in 9-fs Intense Laser Fields Reviewed

Akitaka Matsuda, Mizuho Fushitani, Richard A. Thomas, Vitali Zhaunerchyk, Akiyoshi Hishikawa

JOURNAL OF PHYSICAL CHEMISTRY A Vol. 113 ( 11 ) page： 2254 - 2260 2009.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The fragmentation of deuterated benzene (CA) in ultrashort intense laser fields (9 fs, 1 x 10(15) W/cm(2)) is studied by the ion-coincidence momentum imaging technique. Five two-body and eight three-body Coulomb explosion pathways from the trication (C6D63+), associated with the deprotonation and ring-opening reactions, are identified. It is found from the fragment momentum correlation that all the observed three-body explosion processes proceed sequentially via the two-body Coulomb explosion forming molecular dications, CmDn2+, with (m,n) = (6,5), (5,5), (5,4), (4,4), (4,3), and (3,3), which further dissociate into pairs of monocations. The branching ratio of the fragmentation pathways estimated from the number of the observed coincidence events indicates that the fragmentation is nonstatistical.

DOI： 10.1021/jp806466x

Web of Science

Electron-ion coincidence momentum imaging of molecular dissociative ionization in intense laser fields: Application to CS2 Reviewed

Akitaka Matsuda, Mizuho Fushitani, Akiyoshi Hishikawa

JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA Vol. 169 ( 2-3 ) page： 97 - 101 2009.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER

An electron-ion coincidence momentum imaging apparatus has been developed and applied to dissociative ionization of CS2 in ultrashort intense laser fields. Photoelectron images of CS2 in 35 fs intense laser fields (2 x 10(13) W/cm(2), 800 nm, linearly polarized) recorded in coincidence with the parent ion, CS2+, show clear concentric ring patterns due to the above-threshold ionization (ATI) process. On the other hand, broad structureless distributions elongated along the direction of the laser polarization are observed in the coincidence electron images for the CS+ and S' fragment ions. The difference in the electron images indicates that the dissociative ionization does not proceed sequentially by the formation and photodissociation of CS2+ in intense laser fields. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.elspec.2008.12.004

Web of Science

Electron-ion coincidence momentum imaging of molecular dissociative ionization in intense laser fields: Application to CS(2) Reviewed

Matsuda, A. and Fushitani, M. and Hishikawa, A.

Journal of Electron Spectroscopy and Related Phenomena Vol. 169 ( 2-3 ) page： 97-101 2009

Language：English Publishing type：Research paper (scientific journal)

An electron-ion coincidence momentum imaging apparatus has been developed and applied to dissociative ionization of CS(2) in ultrashort intense laser fields. Photoelectron images of CS(2) in 35 fs intense laser fields (2 x 10(13) W/cm(2), 800 nm, linearly polarized) recorded in coincidence with the parent ion, CS(2)(+), show clear concentric ring patterns due to the above-threshold ionization (ATI) process. On the other hand, broad structureless distributions elongated along the direction of the laser polarization are observed in the coincidence electron images for the CS(+) and S' fragment ions. The difference in the electron images indicates that the dissociative ionization does not proceed sequentially by the formation and photodissociation of CS(2)(+) in intense laser fields. (C) 2008 Elsevier B.V. All rights reserved.

Multiple Explosion Pathways of the Deuterated Benzene Trication in 9-fs Intense Laser Fields Reviewed

Matsuda, A. and Fushitani, M. and Thomas, R. A. and Zhaunerchyk, V. and Hishikawa, A.

Journal of Physical Chemistry A Vol. 113 ( 11 ) page： 2254-2260 2009

Language：English Publishing type：Research paper (scientific journal)

The fragmentation of deuterated benzene (CA) in ultrashort intense laser fields (9 fs, 1 x 10(15) W/cm(2)) is studied by the ion-coincidence momentum imaging technique. Five two-body and eight three-body Coulomb explosion pathways from the trication (C(6)D(6)(3+)), associated with the deprotonation and ring-opening reactions, are identified. It is found from the fragment momentum correlation that all the observed three-body explosion processes proceed sequentially via the two-body Coulomb explosion forming molecular dications, C(m)D(n)(2+), with (m,n) = (6,5), (5,5), (5,4), (4,4), (4,3), and (3,3), which further dissociate into pairs of monocations. The branching ratio of the fragmentation pathways estimated from the number of the observed coincidence events indicates that the fragmentation is nonstatistical.

Time-resolved reaction imaging by intense few-cycle laser pulses and laser high-order harmonics Reviewed

M. Fushitani, A. Matsuda, E. J. Takahashi, A. Hishikawa

Journal of Physics: Conference Series Vol. 185 2009

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Institute of Physics Publishing

We discuss two novel approaches to visualize ultrafast dynamics of polyatomic molecules using few-cycle intense laser pulses and the high-order harmonics in the soft X-ray region, respectively. First, we present the real-time Coulomb explosion imaging of ultrafast isomerization of C 2D2 2+ by using intense few-cycle laser pulses (&lt
10 fs, ∼1 PW/cm2, ∼800 nm) to show that the hydrogen migration proceeds recurrently in competition with the molecular dissociation. Secondly, we present a new experimental setup for the real-time inner-core excitation imaging, focusing on the generation and separation of the light source using the 59th order harmonic pulses (∼91 eV) and their characteristics. © 2009 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/185/1/012009

Scopus

Acetylene-vinylidene isomerization in ultrashort intense laser fields studied by triple ion-coincidence momentum imaging Reviewed

Akiyoshi Hishikawa, Akitaka Matsuda, Eiji J. Takahashi, Mizuho Fushitani

JOURNAL OF CHEMICAL PHYSICS Vol. 128 ( 8 ) 2008.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

The isomerization of acetylene via hydrogen migration in intense laser fields (8 X 10 14 W/cm(2)) has been investigated by coincidence momentum imaging of the three-body Coulomb explosion process, C(2)H(2)(3+)-> H(+)C(+)CH(+). When ultrashort (9 fs) laser pulses are used, the angle between the momenta of C(+) and H(+) fragments exhibits a sharp distribution peaked at a small angle (similar to 20 degrees), showing that the hydrogen atom remains near the original carbon site in the acetylene configuration. On the other hand, a significantly broad distribution extending to larger momentum angles (similar to 120 degrees) is observed when the pulse duration is increased to 35 fs, indicating that the ultrafast isomerization to vinylidene is induced in the longer laser pulse, (c) 2008 American Institute of Physics.

DOI： 10.1063/1.2828557

Web of Science

Acetylene-vinylidene isomerization in ultrashort intense laser fields studied by triple ion-coincidence momentum imaging Reviewed

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

Journal of Chemical Physics Vol. 128 ( 8 ) page： 084302 2008

Language：English Publishing type：Research paper (scientific journal)

DOI： Doi 10.1063/1.2828557

Visualizing recurrently migrating hydrogen in acetylene dication by intense ultrashort laser pulses Reviewed

Akiyoshi Hishikawa, Akitaka Matsuda, Mizuho Fushitani, Eiji J. Takahashi

PHYSICAL REVIEW LETTERS Vol. 99 ( 25 ) 2007.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSICAL SOC

We demonstrate the visualization of ultrafast hydrogen migration in deuterated acetylene dication (C(2)D(2)(2+)) by employing the pump-probe Coulomb explosion imaging with sub-10-fs intense laser pulses (9 fs, 0.13 PW/cm(2), 800 nm). It is shown, from the temporal evolution of the momenta of the fragment ions produced by the three-body explosion, C(2)D(2)(3+) -> D(+)+C(+)+CD(+), that the migration proceeds in a recurrent manner: The deuterium atom first shifts from one carbon site to the other in a short time scale (similar to 90 fs) and then migrates back to the original carbon site by 280 fs, in competition with the molecular dissociation.

DOI： 10.1103/PhysRevLett.99.258302

Web of Science

Dalitz plot analysis of Coulomb exploding O-3 in ultrashort intense laser fields Reviewed

Akitaka Matsuda, Eiji J. Takahashi, Akiyoshi Hishikawa

JOURNAL OF CHEMICAL PHYSICS Vol. 127 ( 11 ) 2007.9

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

The three-body Coulomb explosion of O-3, O-3(3+)-> O++O++O+, in ultrashort intense laser fields (2x10(15) W/cm(2)) is studied with two different pulse durations (9 and 40 fs) by the coincidence momentum imaging method. In addition to a decrease in the total kinetic energy release, a broadening in the Dalitz plot distribution [Philos. Mag. 44, 1068 (1953)] is observed when the pulse duration is increased from 9 to 40 fs. The analysis based on a simple Coulomb explosion model shows that the geometrical structure of O-3 remains almost unchanged during the interaction with the few-cycle intense laser fields, while a significant structural deformation along all the three vibrational coordinates, including the antisymmetric stretching coordinate, is identified in the 40 fs intense laser fields. The observed nuclear dynamics are discussed in terms of the population transfer to the excited states of O-3. (c) 2007 American Institute of Physics.

DOI： 10.1063/1.2766718

Web of Science

Electronic and nuclear responses of fixed-in-space H2S to ultrashort intense laser fields (vol 97, art no 243002, 2006) Reviewed

Akiyoshi Hishikawa, Eiji J. Takahashi, Akitaka Matsuda

PHYSICAL REVIEW LETTERS Vol. 98 ( 1 ) 2007.1

Visualizing recurrently migrating hydrogen in acetylene dication by intense ultrashort laser pulses Reviewed

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

Physical Review Letters Vol. 99 ( 25 ) page： 258302 2007

Language：English Publishing type：Research paper (scientific journal)

DOI： Doi 10.1103/Physrevlett.99.258302

Dalitz plot analysis of Coulomb exploding O-3 in ultrashort intense laser fields Reviewed

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

Journal of Chemical Physics Vol. 127 ( 11 ) page： 114318 2007

Language：English Publishing type：Research paper (scientific journal)

DOI： Doi 10.1063/1.2766718

Coincidence momentum imaging of two- and three-body Coulomb explosion of ethanol in intense laser fields Reviewed

Ryuji Itakura, Takahiro Teramoto, Akiyoshi Hishikawa, Kaoru Yamanouchi

ULTRAFAST OPTICS V Vol. 132 page： 375 - + 2007

Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPRINGER

Dissociative ionization of ethanol in intense laser fields is investigated by the coincidence momentum imaging method. Two-body Coulomb explosion channels with the hydrogen migration are identified in addition to a three-body Coulomb explosion channel. On the basis of the momentum vector distributions of the fragment ions, the dissociative ionization dynamics is discussed.

DOI： 10.1007/978-0-387-49119-6_49

Web of Science

Coulomb explosion imaging of molecular dynamics in intense laser fields Reviewed

Akiyoshi Hishikawa, Kaoru Yamanouchi

Springer Series in Chemical Physics Vol. 85 page： 1 - 24 2007

Language：English Publishing type：Research paper (international conference proceedings)

The nuclear dynamics of polyatomic molecules in intense laser fields (∼1 PW/cm2) is studied through the momentum imaging of the fragment ions produced through Coulomb explosion. Characteristic nuclear dynamics that occur on the multidimensional potential energy surfaces in intense laser fields, such as sequential and concerted bond-breaking and hydrogen migration, are elucidated from momentum correlations among the fragment ions. © 2007 Springer-Verlag.

DOI： 10.1007/978-3-540-38156-3-1

Scopus

Visualizing recurrently migrating hydrogen by few-cycle intense laser pulses Reviewed

Akiyoshi Hishikawa, Akitaka Matsudal, Mizuho Fushitani, Eiji J. Takahashi

XXV INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS Vol. 88 page： 12056 2007

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Ultrafast hydrogen migration in deuterated acetylene dication (C(2)D(2)(2+)) is studied by the pump-probe Coulomb explosion imaging with few-cycle intense laser pulses (9 fs, 0.13 PW/cm(2), 800 nm). The temporal evolution of the momenta of the fragment ions produced by the three-body explosion, C(2)D(2)(3+) -> D(+) + C(+) + CD(+), shows that the migration proceeds in a recurrent manner: The deuterium atom first shifts from one carbon site to the other in a short time scale (similar to 90 fs), and then migrates back to the original carbon site by 280 fs, in competition with the molecular dissociation.

DOI： 10.1088/1742-6596/88/1/012056

Web of Science

Visualizing recurrently migrating hydrogen by few-cycle intense laser pulses Reviewed

Akiyoshi Hishikawa, Akitaka Matsudal, Mizuho Fushitani, Eiji J. Takahashi

XXV INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS Vol. 88 2007

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

DOI： 10.1088/1742-6596/88/1/012056

Web of Science

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Papers - HISHIKAWA, Akiyoshi