1. |
- Boll, Rebecca, et al.
(författare)
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Imaging molecular structure through femtosecond photoelectron diffraction on aligned and oriented gas-phase molecules
- 2014
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Ingår i: Faraday Discussions. - : Royal Society of Chemistry (RSC). - 1364-5498. ; 171, s. 57-80
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Tidskriftsartikel (refereegranskat)abstract
- This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump-probe setup combining optical lasers and an X-ray free-electron laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) and dissociating, laser-aligned 1,4-dibromobenzene (C6H4Br2) molecules and discuss them in the larger context of photoelectron diffraction on gas-phase molecules. We also show how the strong nanosecond laser pulse used for adiabatically laser-aligning the molecules influences the measured electron and ion spectra and angular distributions, and discuss how this may affect the outcome of future time-resolved photoelectron diffraction experiments.
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2. |
- Kuepper, Jochen, et al.
(författare)
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X-Ray Diffraction from Isolated and Strongly Aligned Gas-Phase Molecules with a Free-Electron Laser
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:8, s. 083002-
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Tidskriftsartikel (refereegranskat)abstract
- We report experimental results on x-ray diffraction of quantum-state-selected and strongly aligned ensembles of the prototypical asymmetric rotor molecule 2,5-diiodobenzonitrile using the Linac Coherent Light Source. The experiments demonstrate first steps toward a new approach to diffractive imaging of distinct structures of individual, isolated gas-phase molecules. We confirm several key ingredients of single molecule diffraction experiments: the abilities to detect and count individual scattered x-ray photons in single shot diffraction data, to deliver state-selected, e.g., structural-isomer-selected, ensembles of molecules to the x-ray interaction volume, and to strongly align the scattering molecules. Our approach, using ultrashort x-ray pulses, is suitable to study ultrafast dynamics of isolated molecules.
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3. |
- Leitner, Torsten, 1979-, et al.
(författare)
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Coherent wave packet dynamics in photo-excited Nal
- 2013
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. - 9782759809561 ; 41, s. 02027-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Time and energy resolved photoelectron distributions of photo-excited Nal are presented. A splitting in the photo-excited state suggested by calculations of the intramolecular potential energy surfaces could be confirmed experimentally for the first time.
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4. |
- Rouzée, Arnaud, et al.
(författare)
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Molecular Movies from Molecular Frame Photoelectron Angular Distribution (MF-PAD) Measurements
- 2014
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Ingår i: Ultrafast Phenomena in Molecular Sciences : Femtosecond Physics and Chemistry - Femtosecond Physics and Chemistry. - Cham : Springer International Publishing. - 0172-6218. - 9783319020501 ; 107, s. 1-24
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Bokkapitel (refereegranskat)abstract
- We discuss recent and on-going experiments, where molecular frame photoelectron angular distributions (MFPADs) of high kinetic energy photoelectrons are measured in order to determine the time evolution of molecular structures in the course of a photochemical event. These experiments include, on the one hand, measurements where single XUV/X-ray photons, obtained from a free electron laser (FEL) or by means of high-harmonic generation (HHG), are used to eject a high energy photoelectron, and, on the other hand, measurements where a large number of mid-infrared photons are absorbed in the course of strong-field ionization. In the former case, first results indicate a manifestation of the both the electronic orbital and the molecular structure in the angle-resolved photoelectron distributions, while in the latter case novel holographic structures are measured that suggest that both the molecular structure and ultrafast electronic rearrangement processes can be studied with a time-resolution that reaches down into the attosecond and few-femtosecond domain.
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