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Showing result 1 - 5 of 11 swedish dissertations matching the above criteria.

  2. 1. Dissociation dynamics of highly excited molecules: Theory and Experiment

    Author : Shabnam Oghbaie; Synkrotronljusfysik; []
    Keywords : Molecular dissociation; core-electron excitation; double ionization; femtoseconds molecular dynamics; Isomerization; symmetry breaking; momentum imaging; site-selective dissociation; butadiene; cyclopropane; nuclear dynamics; Auger decay;

    Abstract : This thesis presents studies on dissociation of two model molecules: Butadiene and Cyclopropane. Tunable synchrotron radiation was used to ionize or excite the molecules in the gas phase, and the momentum correlation of the resulting fragment ions were measured using a 3D momenta coincident ion spectroscopy. READ MORE

  4. 2. Ultrafast Magnetization Dynamics : Element-selective studies of magnetic alloys using ultra short XUV pulses

    Author : Rameez Saeed Malik; Olof Karis; Uwe Bovensiepen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; magnetization dynamics; magnetic alloys; HHG; ultrashort laser pulses; magneto-optical Kerr effect MOKE ; Gilbert damping; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : In this thesis, I investigate the ultrafast magnetization dynamics in 3d ferromagnets and their alloys with ultrashort laser pulses. The high harmonics generation (HHG) setup provides extreme-ultraviolet photons with energies 35-72 eV, which is the energy range where 3d metals have their M2,3 absorption edges. READ MORE

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

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

    Abstract : 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. READ MORE

  6. 4. Ultra-fast dynamics in atoms and molecules during photoionization: from attoseconds to femtoseconds

    Author : Erik Månsson; Synkrotronljusfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; photoelectron spectroscopy; momentum imaging; coincident detection; correlation; direct double ionization; Born–Oppenheimer approximation; high harmonics; synchrotron radiation; Fysicumarkivet A:2014:Månsson;

    Abstract : Treating the correlated behaviour of multiple particles is challenging for both theory and experiment. This thesis reports on a variety of experimental investigations aiming to advance the understanding of fundamental processes in atoms and molecules: double ionization, isomerization and dissociation. READ MORE

  7. 5. Time-Resolved Diffraction Studies of Structural Dynamics in Solids

    Author : Xiaocui Wang; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Time-resolved X-ray diffraction; phonons; photo-acoustic transducer; electron diffusion; pressure wave; non-thermal melting; Fysicumarkivet A:2019:Wang;

    Abstract : Studies of the structural dynamics of solids can improve our understanding of atomic motion in materials, and may thus help in the manufacture of new devices or the development of materials with novel structures and properties. Ultrashort laser pulses, a few tens of femtoseconds long, can deliver high energies (mJ–kJ). READ MORE