Sökning: "Free-Electron Lasers"

Visar resultat 16 - 20 av 40 avhandlingar innehållade orden Free-Electron Lasers.

1. 16. X-ray scattering and spectroscopy of supercooled water and ice

   Författare :Jonas A. Sellberg; Anders Nilsson; Lars G. M. Pettersson; Thomas Loerting; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supercooled water; ice; x-ray scattering; x-ray spectroscopy; free-electron laser; kemisk fysik; Chemical Physics;

   Sammanfattning : This thesis presents experimental studies of water and ice at near-atmospheric pressures using intense x-rays only accessible at synchrotrons and free-electron lasers. In particular, it focuses on the deeply supercooled, metastable state and its implications on ice nucleation. LÄS MER

3. 17. 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

4. 18. Simulations of Biomolecular Fragmentation and Diffraction with Ultrafast X-ray Lasers

   Författare :Christofer Östlin; Carl Caleman; Nicusor Timneanu; Helmut Grubmüller; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray free-electron laser; X-ray imaging; Single particle imaging; Computer simulation; Radiation damage; Molecular dynamics; Diffraction theory; Coulomb explosion; Sample heterogeneity; Diffractive noise; XFEL; SPI; Physics with specialization in Biophysics; Fysik med inriktning mot biofysik;

   Sammanfattning : Studies of biomolecules have recently seen substantial developments. New X-ray lasers allow for high-resolution imaging of protein crystals too small for conventional X-ray crystallography. Even structures of single particles have been determined at lower resolutions with these new sources. LÄS MER

5. 19. Simulations of ultrafast photon-matter interactions for molecular imaging with X-ray lasers

   Författare :Ibrahim Eliah Dawod; Nicusor Timneanu; Carl Caleman; Adrian P. Mancuso; Lars Schäfer; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray free-electron laser; molecular dynamics; radiation damage; plasma simulations; density functional theory¸ coherent diffractive imaging; protein structure; X-ray crystallography; single particle imaging;

   Sammanfattning : Biological structure determination has had new avenues of investigation opened due to the introduction of X-ray free-electron lasers (XFELs). These X-ray lasers provide an extreme amount of photons on ultrafast timescales used to probe matter, and in particular biomolecules. LÄS MER

7. 20. Algorithms for Coherent Diffractive Imaging with X-ray Lasers

   Författare :Benedikt J. Daurer; Filipe Maia; Tomas Ekeberg; Janos Hajdu; Richard Neutze; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; X-ray lasers; coherent diffractive imaging; algorithms; lensless imaging; flash diffractive imaging; flash X-ray imaging; aerosol injection; FEL; XFEL; CXI; CDI; FXI; Physics with specialization in Biophysics; Fysik med inriktning mot biofysik;

   Sammanfattning : Coherent diffractive imaging (CDI) has become a very popular technique over the past two decades. CDI is a "lensless" imaging method which replaces the objective lens of a conventional microscope by a computational image reconstruction procedure. LÄS MER