Sökning: "above threshold ionization"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden above threshold ionization.
1. Ionization of large molecules with short laser pulses
Sammanfattning : The decay dynamics of fullerenes and polyaromatic hydrocarbons (PAH) after femtosecond-laser excitation have been studied experimentally by electron momentum mapping and mass spectrometry. The electron spectra of fullerenes and large PAH-molecules were found to be exponentially decreasing with energy without any distinct peaks outside the photon energy. LÄS MER
2. Two photon above threshold ionization in a relativistic framework : Attosecond delays in high Z elements
Sammanfattning : Recent advances in experimental physics opens up for improved time resolution on measurements of ionizing processes in atoms caused by an EM-field. There exist non-relativistic models that describe photo-ionization events involving two photons, for various atoms, where relativistic effects, e.g. spin-orbit interactions, are small. LÄS MER
3. Soft X-ray Scattering Dynamics Close to Core Ionization Thresholds in Atoms and Molecules
Sammanfattning : In this Thesis studies of highly excited states in gas-phase atoms and molecules (He, Ne, N2, O2, N2O and CO2) using a variety of synchrotron-radiation based techniques are presented. The three techniques used most frequently are X-ray-emission-threshold-electron coincidence (XETECO), X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy (XPS) and they are all given a brief introduction. LÄS MER
4. Attosecond photoelectron interferometry: from wavepackets to density matrices
Sammanfattning : Through the advent of high-order harmonic generation and attosecond light pulses, photoionization dynamics has been studied on the attosecond time-scale, the intrinsic time-scale of such dynamics. When the electron leaves the atomic potential a phase shift is imprinted on the electron wavefunction. LÄS MER
5. Time-of-Flight Ion and Electron Spectroscopy: Applications and Challenges at Storage Ring Light Sources
Sammanfattning : This dissertation contains seven studies exploring novel instrumentation for ion and electron spectroscopy, including their applicability at storage ring light sources. The studies focus on instrumentation to study decay, dynamics and dissociation of photoexcited molecules, and the possibility to host such instruments at MAX~IV. LÄS MER
