| 1. |
- Mondal, S., et al.
(författare)
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Photoelectron angular distributions for the two-photon sequential double ionization of xenon by ultrashort extreme ultraviolet free electron laser pulses
- 2013
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
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Tidskriftsartikel (refereegranskat)abstract
- Xenon atoms are double-ionized by sequential two-photon absorption by ultrashort extreme ultraviolet free-electron laser pulses with a photon energy of 23.0 and 24.3 eV, produced by the SPring-8 Compact SASE Source test accelerator. The angular distributions of photoelectrons generated by two-photon double ionization are obtained using velocity map imaging. The results are reproduced reasonably well by the present theoretical calculations within the multi-configurational Dirac-Fock approach.
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| 2. |
- Gryzlova, E. V., et al.
(författare)
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Doubly resonant three-photon double ionization of Ar atoms induced by an EUV free-electron laser
- 2011
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 84:6
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Tidskriftsartikel (refereegranskat)abstract
- A mechanism for three-photon double ionization of atoms by extreme-ultraviolet free-electron laser pulses is revealed, where in a sequential process the second ionization step, proceeding via resonant two-photon ionization of ions, is strongly enhanced by the excitation of ionic autoionizing states. In contrast to the conventional model, the mechanism explains the observed relative intensities of photoelectron peaks and their angular dependence in three-photon double ionization of argon.
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| 3. |
- Ma, R., et al.
(författare)
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Photoelectron angular distributions for the two-photon ionization of helium by ultrashort extreme ultraviolet free-electron laser pulses
- 2013
-
Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
-
Tidskriftsartikel (refereegranskat)abstract
- The two-photon ionization of helium atoms by ultrashort extreme-ultraviolet free-electron laser pulses, produced by the SPring-8 Compact SASE Source test accelerator, was investigated at photon energies of 20.3, 21.3, 23.0 and 24.3 eV. The angular distribution of photoelectrons generated by two-photon ionization is obtained using a velocity map imaging spectrometer. The phase-shift differences and amplitude ratios of the outgoing s and d continuum wave packets are extracted from the photoelectron angular distributions. The obtained values of the phase-shift differences are distinct from scattering phase-shift differences when the photon energy is tuned to a resonance with an excited level or Rydberg manifold. The difference stems from the co-presence of resonant and non-resonant path contributions in the two-photon ionization by femtosecond pulses. Since the relative contribution of both paths can be controlled in principle by the pulse shape, these results illustrate a new way to tailor the continuum wave packet.
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| 4. |
- Nagaya, K., et al.
(författare)
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Multiple photoionization of rare-gas clusters by EUV-FEL at Spring-8
- 2012
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 388:3, s. 032082-
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Tidskriftsartikel (refereegranskat)abstract
- Multiple photoionization processes of giant rare-gas clusters are investigated in the wavelength region of 51 to 61nm at Spring8. We report here some latest results of our investigation; the frustration of photoionization for giant xenon clusters and the charge transfer in Ar-core Ne-shell clusters.
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| 5. |
- Sugishima, A., et al.
(författare)
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Charge and energy transfer in argon-core-neon-shell clusters irradiated by free-electron-laser pulses at 62 nm
- 2012
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 86:3, s. 033203-
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Tidskriftsartikel (refereegranskat)abstract
- The multiple ionization of Ar-core-Ne-shell clusters in intense extreme-ultraviolet laser pulses (lambda similar to 62 nm) from the free-electron laser in Japan was investigated utilizing a momentum imaging technique. The Ar composition dependence of the kinetic energies and the yields of the fragment ions give evidence for charge transfer from the Ar core to the Ne shell. We have extended the uniformly charged sphere model originally applied to pristine clusters [Islam et al., Phys. Rev. A 73, 041201 (R) (2006)] to the core-shell heterogeneous clusters to estimate the amounts of charge and energy transfers.
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