Firstly, a non equilibrium model is developed in order to simulate non ideal multicomponent react... more Firstly, a non equilibrium model is developed in order to simulate non ideal multicomponent reactive separation processes. This model is characterised by mass and energy transfer description completed up by hydrodynamics consideration based on the film theory model. The Maxwell Stefan approach is used for the description of mass transfer without restrictive hypotheses. Moreover, there are no restrictive hypotheses about
Two-photon excitation of a single-photon forbidden Auger resonance has been observed and investig... more Two-photon excitation of a single-photon forbidden Auger resonance has been observed and investigated using the intense extreme ultraviolet radiation from the free electron laser in Hamburg. At the wavelength 26.9 nm (46 eV) two photons promoted a 3d core electron to the outer 4d shell. The subsequent Auger decay, as well as several nonlinear above threshold ionization processes, were studied by electron spectroscopy. The experimental data are in excellent agreement with theoretical predictions and analysis of the underlying multiphoton processes.
The absolute photoionization cross sections of the excited, short-lived He* 1s2p 1P and 1s3p 1P s... more The absolute photoionization cross sections of the excited, short-lived He* 1s2p 1P and 1s3p 1P states are determined experimentally in the region close to the He+ 1s 2S threshold (from 0 to 2 eV). The intermediate He* states are prepared by photoabsorption of a high-order harmonic of an intense picosecond tunable laser and subsequently ionized by absorption of photons of
In the photoelectron spectrum of N2 the apparent ionization energy to form the BSigmau+2 state in... more In the photoelectron spectrum of N2 the apparent ionization energy to form the BSigmau+2 state increases linearly with the photon energy. Rotationally resolved measurements of the fluorescent decay of this state show a linear increase of rotational heating with increasing photon energy. These results are in quantitative agreement with the prediction of the theory of recoil-induced rotational excitation, indicating that
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
Recent experiments using the combination of conventional lasers and synchrotron radiation are pre... more Recent experiments using the combination of conventional lasers and synchrotron radiation are presented and discussed. The controlled laser-manipulation of atoms prior to ionization by the synchrotron radiation provides an ideal experimental basis for detailed investigations of atomic photoionization. Due to the recent advances in high-resolution electron spectroscopy, it has become possible to analyze the J-resolved fine structure of the final
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
Two-color experiments combining synchrotron radiation from the SuperACO storage ring in Orsay (Fr... more Two-color experiments combining synchrotron radiation from the SuperACO storage ring in Orsay (France) and conventional dye lasers have been performed to investigate excited atoms and molecules. Synchronization between synchrotron and laser pulses has been applied to study even-parity Xe*5p5 mf′, np′ autoionization states of atomic xenon via the short-lived intermediate states Xe* 5p5 (2P3/2) 5d and 6d. In addition, we
Two-color photoionization processes in rare gases have been studied using the combination of XUV ... more Two-color photoionization processes in rare gases have been studied using the combination of XUV pulses from the Free Electron Laser in Hamburg (FLASH) and intense femtosecond pulses from an external synchronized near infrared laser. In the low field regime of the NIR dressing laser (<1011 W/cm2), the partial cross sections of the two-photon ionization were determined by measuring the polarization
We have performed high-resolution photoionization experiments in laser-excited atoms by combining... more We have performed high-resolution photoionization experiments in laser-excited atoms by combining a cw dye laser and the photon beam available at the 10.0.1 station of the Advanced Light Source. Photoelectron ejected from laser-excited sodium atoms were analyzed using a high-resolution hemispherical Scienta analyzer. Ultimate resolution (FWHM) was 13 meV, while previous experiments were performed with 200 to 300 meV resolution [1, 2]. Strong differences are observed in the relative intensity of various J-resolvved photoelectron lines following inner-shell 2p ionization when the laser is tuned to the 3s--3p1/2 or 3s--3p3/2 transition. The lifetime of some 2p53s3p strongly autoionizing states has been measured to be surprizingly long. Detailed results will be presented at the meeting. [1] J. M. Bizau et al., Phys. Rev. Lett. 55, 1281 (1985) [2] D. Cubaynes et al., Phys. Rev. Lett. 63, 2460 (1989)
Firstly, a non equilibrium model is developed in order to simulate non ideal multicomponent react... more Firstly, a non equilibrium model is developed in order to simulate non ideal multicomponent reactive separation processes. This model is characterised by mass and energy transfer description completed up by hydrodynamics consideration based on the film theory model. The Maxwell Stefan approach is used for the description of mass transfer without restrictive hypotheses. Moreover, there are no restrictive hypotheses about
Two-photon excitation of a single-photon forbidden Auger resonance has been observed and investig... more Two-photon excitation of a single-photon forbidden Auger resonance has been observed and investigated using the intense extreme ultraviolet radiation from the free electron laser in Hamburg. At the wavelength 26.9 nm (46 eV) two photons promoted a 3d core electron to the outer 4d shell. The subsequent Auger decay, as well as several nonlinear above threshold ionization processes, were studied by electron spectroscopy. The experimental data are in excellent agreement with theoretical predictions and analysis of the underlying multiphoton processes.
The absolute photoionization cross sections of the excited, short-lived He* 1s2p 1P and 1s3p 1P s... more The absolute photoionization cross sections of the excited, short-lived He* 1s2p 1P and 1s3p 1P states are determined experimentally in the region close to the He+ 1s 2S threshold (from 0 to 2 eV). The intermediate He* states are prepared by photoabsorption of a high-order harmonic of an intense picosecond tunable laser and subsequently ionized by absorption of photons of
In the photoelectron spectrum of N2 the apparent ionization energy to form the BSigmau+2 state in... more In the photoelectron spectrum of N2 the apparent ionization energy to form the BSigmau+2 state increases linearly with the photon energy. Rotationally resolved measurements of the fluorescent decay of this state show a linear increase of rotational heating with increasing photon energy. These results are in quantitative agreement with the prediction of the theory of recoil-induced rotational excitation, indicating that
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
Recent experiments using the combination of conventional lasers and synchrotron radiation are pre... more Recent experiments using the combination of conventional lasers and synchrotron radiation are presented and discussed. The controlled laser-manipulation of atoms prior to ionization by the synchrotron radiation provides an ideal experimental basis for detailed investigations of atomic photoionization. Due to the recent advances in high-resolution electron spectroscopy, it has become possible to analyze the J-resolved fine structure of the final
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
Two-color experiments combining synchrotron radiation from the SuperACO storage ring in Orsay (Fr... more Two-color experiments combining synchrotron radiation from the SuperACO storage ring in Orsay (France) and conventional dye lasers have been performed to investigate excited atoms and molecules. Synchronization between synchrotron and laser pulses has been applied to study even-parity Xe*5p5 mf′, np′ autoionization states of atomic xenon via the short-lived intermediate states Xe* 5p5 (2P3/2) 5d and 6d. In addition, we
Two-color photoionization processes in rare gases have been studied using the combination of XUV ... more Two-color photoionization processes in rare gases have been studied using the combination of XUV pulses from the Free Electron Laser in Hamburg (FLASH) and intense femtosecond pulses from an external synchronized near infrared laser. In the low field regime of the NIR dressing laser (<1011 W/cm2), the partial cross sections of the two-photon ionization were determined by measuring the polarization
We have performed high-resolution photoionization experiments in laser-excited atoms by combining... more We have performed high-resolution photoionization experiments in laser-excited atoms by combining a cw dye laser and the photon beam available at the 10.0.1 station of the Advanced Light Source. Photoelectron ejected from laser-excited sodium atoms were analyzed using a high-resolution hemispherical Scienta analyzer. Ultimate resolution (FWHM) was 13 meV, while previous experiments were performed with 200 to 300 meV resolution [1, 2]. Strong differences are observed in the relative intensity of various J-resolvved photoelectron lines following inner-shell 2p ionization when the laser is tuned to the 3s--3p1/2 or 3s--3p3/2 transition. The lifetime of some 2p53s3p strongly autoionizing states has been measured to be surprizingly long. Detailed results will be presented at the meeting. [1] J. M. Bizau et al., Phys. Rev. Lett. 55, 1281 (1985) [2] D. Cubaynes et al., Phys. Rev. Lett. 63, 2460 (1989)
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