Faculty Profiles - HISHIKAWA, Akiyoshi

EUV and soft X-ray photoelectron spectroscopy of isolated atoms and molecules using single-order laser high-harmonics at 42 eV and 91 eV Reviewed

レーザークーロン爆発イメージングによる実時間反応追跡 Invited Reviewed

菱川明栄

レーザー研究 Vol. 40 page： 745-751 2012.10

EUV and soft X-ray photoelectron spectroscopy of isolated atoms and molecules using single-order laser high-harmonics at 42 eV and 91 eV Reviewed

M. Fushitani, A. Matsuda and A. Hishikawa

J. Electron. Spectrosc. Relat. Phenom. Vol. 184 page： 561-568 2012.2

極紫外自由電子レーザー場における原子のシングルショット光電子分光 Invited Reviewed

彦坂泰正，伏谷瑞穂，菱川明栄

しょうとつ Vol. 9 ( 1 ) page： 5-10 2012.1

Mizuho Fushitani, Akitaka Matsuda, Akiyoshi Hishikawa

JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA Vol. 184 ( 11-12 ) page： 561 - 568 2012.1

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

Photoelectron spectroscopy of isolated atoms and molecules using single-order high-harmonics of Ti:Sapphire laser pulses (800 nm, 12 fs/30 fs) is demonstrated. Dielectric multilayer mirrors, SiC/Mg and Mo/Si, are used to isolate the 27th (42 eV) and 59th (91 eV) order harmonics, respectively. The obtained harmonics are characterized by valence and inner-shell photoelectron spectroscopy of Xe. The applications to two-color two-photon ionization of He and pump-probe spectroscopy of ultrafast photodissociation of Br-2, Br-2(C-1 Pi(u)) --> Br(P-2(3/2))+ Br(P-2(3/2)), are presented. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.elspec.2011.10.002

Theoretical study of multi-photon double electron excitation of He by intense ultrashort EUV pulses Reviewed

Chien-Nan Liu, Toru Morishita, Shinichi Watanabe, Akiyoshi Hishikawa

XXVII INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS (ICPEAC 2011), PTS 1-15 Vol. 388 ( PART 3 ) 2012

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

We use the time-dependent hypersperhical close-coupling method to study the double excitation of helium atoms by intense ultrashort XUV pulses. In addition to showing the photoelectron yield spectra, we demonstrate that free electron lasers can be used to efficiently create doubly excited electron wave packets, opening up the possibility of visualizing the correlated motion of electrons in atoms.

DOI： 10.1088/1742-6596/388/3/032007

Visualizing correlated dynamics of hydrogen atoms in acetylene dication by time-resolved four-body coulomb explosion imaging Reviewed

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

Springer Proceedings in Physics Vol. 125 page： 317 - 322 2012

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Springer Science and Business Media, LLC

Ultrafast hydrogenmigration in deuterated acetylene dication (C 2D2+2 ) is studied by time-resolved four-body Coulomb explosion imaging, C2D4+ 2 → D++ C ++ C ++ D +, using a pair of few-cycle intense laser pulses (9 fs, 1.3 × 1014 W/cm 2). Momentum correlation of the D+ ions produced by the full fragmentation process shows that (1) motions of the two deuterium atoms are strongly correlated during the isomerization and (2) the molecular structure deforms to nonplanar geometries. © Springer-Verlag Berlin Heidelberg 2012.

DOI： 10.1007/978-3-642-28948-4_53

Enhanced Nonlinear Double Excitation of He in Intense Extreme Ultraviolet Laser Fields Reviewed

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

PHYSICAL REVIEW LETTERS Vol. 107 ( 24 ) page： 243003 2011.12

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

Nonlinear, three-photon double excitation of He in intense extreme ultraviolet free-electron laser fields (similar to 24.1 eV, similar to 5 TW/cm(2)) is presented. Resonances to the doubly excited states converging to the He(+) N = 3 level are revealed by the shot-by-shot photoelectron spectroscopy and identified by theoretical calculations based on the time-dependent Schrodinger equation for the two-electron atom under a laser field. It is shown that the three-photon double excitation is enhanced by intermediate Rydberg states below the first ionization threshold, giving a greater contribution to the photoionization yields than the two-photon process by more than 1 order of magnitude.

DOI： 10.1103/PhysRevLett.107.243003

クーロン爆発イメージングによる超高速反応追跡 Invited

菱川明栄

光アライアンス Vol. 22 ( 11 ) page： 19-22 2011.11

光のゆらぎで探る：自由電子レーザー場中の原子 Invited

伏谷瑞穂, 彦坂泰正, 菱川明栄

光アライアンス Vol. 22 ( 10 ) page： 25-28 2011.10

A magnetic-bottle multi-electron-ion coincidence spectrometer Reviewed

Akitaka Matsuda, Mizuho Fushitani, Chien-Ming Tseng, Yasumasa Hikosaka, John H. D. Eland, Akiyoshi Hishikawa

REVIEW OF SCIENTIFIC INSTRUMENTS Vol. 82 ( 10 ) page： 103105 2011.10

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

A novel multi-electron-ion coincidence spectrometer developed on the basis of a 1.5 m-long magnetic-bottle electron spectrometer is presented. Electrons are guided by an inhomogeneous magnetic field to a detector at the end of the flight tube, while a set of optics is used to extract counterpart ions to the same detector, by a pulsed inhomogeneous electric field. This setup allows ion detection with high mass resolution, without impairing the high collection efficiency for electrons. The performance of the coincidence spectrometer was tested with double ionization of carbon disulfide, CS2 -> CS22+ + e(-) + e(-), in ultrashort intense laser fields (2.8 x 10(13) W/cm(2), 280 fs, 1030 nm) to clarify the electron correlation below the rescattering threshold. (C) 2011 American Institute of Physics. [doi:10.1063/1.3648133]

DOI： 10.1063/1.3648133

Time-resolved EUV photoelectron spectroscopy of dissociating I-2 by laser harmonics at 80 nm Reviewed

Mizuho Fushitani, Akitaka Matsuda, Akiyoshi Hishikawa

OPTICS EXPRESS Vol. 19 ( 10 ) page： 9600 - 9606 2011.5

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

Generation of single-order laser harmonics in extreme ultraviolet (EUV) and the application to the time-resolved photoelectron spectroscopy of I-2 are demonstrated. The EUV pulses at 80 nm were generated from Kr as the 5th order harmonics of intense 400 nm laser pulses and then separated from other harmonic orders by a thin indium foil. The pump-probe photoelectron spectroscopy of I-2 in the B (3)Pi(0(u)(+)) and B" (1)Pi(1(u)) states excited by visible laser pulses at 490 nm showed a rapid increase in the yield of atomic iodine (similar to 400 fs), reflecting the dissociation dynamics evolving simultaneously in the two excited states. (C) 2011 Optical Society of America

DOI： 10.1364/OE.19.009600

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

Time-resolved EUV photoelectron spectroscopy of dissociating I(2) by laser harmonics at 80 nm Reviewed

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

Optics Express Vol. 19 ( 10 ) page： 9600-9606 2011

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

Generation of single-order laser harmonics in extreme ultraviolet (EUV) and the application to the time-resolved photoelectron spectroscopy of I(2) are demonstrated. The EUV pulses at 80 nm were generated from Kr as the 5th order harmonics of intense 400 nm laser pulses and then separated from other harmonic orders by a thin indium foil. The pump-probe photoelectron spectroscopy of I(2) in the B (3)Pi(0(u)(+)) and B" (1)Pi(1(u)) states excited by visible laser pulses at 490 nm showed a rapid increase in the yield of atomic iodine (similar to 400 fs), reflecting the dissociation dynamics evolving simultaneously in the two excited states. (C) 2011 Optical Society of America

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

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

Physical Chemistry Chemical Physics Vol. 13 ( 19 ) page： 8697-8704 2011

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

The visualization of ultrafast isomerization of deuterated acetylene dication (C(2)D(2)(2+)) 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, C(2)D(2)(3+) -> 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, C(2)D(2)(4+) - D(+) + C(+) + C(+) + D(+).

DOI： Doi 10.1039/C0cp02333g

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

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

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

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

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

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

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