Sökning: "ultrafast nuclear dynamics"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden ultrafast nuclear dynamics.

1. 1. Theoretical perspectives on ultrafast and non-linear spectroscopy

   Författare :Emil Vinas Boström; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-linear optics; Ultrafast dynamics; Non-equilibrium Green s functions; Density functional theory; Multi-photon absorption; Second harmonic generation; Desorption dynamics; Auger decay; Charge-separation dynamics; Quantum Zeno effect; Fysicumarkivet A:2018:Vinas Boström;

   Sammanfattning : In this thesis we discuss a theoretical description of ultrafast and non-linear spectroscopy. Due to the high intensities and ultrashort pulse durations involved in such experiments, it is necessary to use an explicitly time-dependent formalism. LÄS MER

3. 2. Investigation of Ultrafast Molecular Dynamics via Covariance Mapping : A Tool for Intense XUV Light Sources

   Författare :Jan Lahl; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Covariance; Ultrafast; High-order harmonic generation; Extreme Ultraviolet; Pump probe; FLASH; Velocity map imaging; wavefront; FEL; photodissociation; Coulomb explosion; Fysicumarkivet A:2019:Lahl;

   Sammanfattning : The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. LÄS MER

4. 3. Quantum chemical calculations of multidimensional dynamics probed in resonant inelastic X-ray scattering

   Författare :Emelie Ertan; Michael Odelius; Åsa Larson; Oriol Vendrell; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; X-ray spectroscopy; RASSCF; density functional theory; ultrafast nuclear dynamics; kemisk fysik; Chemical Physics;

   Sammanfattning : This thesis is devoted to the theoretical study of the dynamical processes induced by light-matter interactions in molecules and molecular systems. To this end, the multidimensional nuclear dynamics probed in resonant inelastic X-ray scattering (RIXS) of small molecules, exemplified by H2O (g) and H2S (g), as well as more complex molecular systems, exemplified by NH3 (aq) and kaolinite clay, are modelled. LÄS MER

5. 4. Ultrafast dynamics of small quantum systems studied using electron-ion coincidence spectroscopy

   Författare :Smita Ganguly; Synkrotronljusfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coincidence spectroscopy; photodissociation dynamics; fragmentation reaction; MOLECULAR-BEAM; Cluster fission; Astrochemistry; Carbon dioxide CO2 ; ; Adamantane;

   Sammanfattning : Studying how small quantum systems, like molecules and clusters, interact with X-rays is crucial to understanding the ultrafast processes that occur in nature on incredibly short timescales, ranging from femtoseconds to picoseconds. X-rays excite small quantum systems to unstable core hole states, leading to a cascade of phenomena, including Auger decay, nuclear rearrangement, and dissociation. LÄS MER

7. 5. Ultrafast Photoionization Dynamics Studied with Coincidence Momentum Imaging Spectrometers

   Författare :Yu-Chen Cheng; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photoionization; High-order Harmonic Generation; Extreme Ultraviolet; Free-Electron Laser; Molecular Dissociation; Charge Transfer; Coincidence Measurement; Momentum Imaging; Electron Wave Packet; Fysicumarkivet A:2019:Cheng;

   Sammanfattning : The time scale of the dynamics in atoms and molecules varies from attoseconds (10-18) to picoseconds (10-12) depending on the size of the particles. To study such dynamics, ultrafast light pulses are needed to trigger and capture the reaction. One of the most direct methods consists in ionizing the system and observing the following response. LÄS MER