Sökning: "ultrafast lasers"

Visar resultat 11 - 15 av 31 avhandlingar innehållade orden ultrafast lasers.

1. 11. 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

3. 12. Atomic and Molecular Dynamics Probed by Intense Extreme Ultraviolet Attosecond Pulses

   Författare :Jasper Peschel; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond science; Ultrafast phenomena; High-order Harmonics Generation; Free Electron Lasers; Photoionization; Photodissociation; Fysicumarkivet A:2021:Peschel;

   Sammanfattning : This thesis work was aimed to investigate dynamical processes in atoms and molecules on ultrafast time scales initiated by absorption of light in the extreme ultraviolet (XUV) regime. In particular, photoionization and photodissociation have been studied using pump-probe techniques involving ultrafast laser pulses. LÄS MER

4. 13. Towards Single Molecule Imaging - Understanding Structural Transitions Using Ultrafast X-ray Sources and Computer Simulations

   Författare :Carl Caleman; Janos Hajdu; Richard Neutze; Uppsala universitet; []
   Nyckelord :Molecular biophysics; XFEL; Ultrafast Melting; InSb; Molecular Dynamics; Water Cluster; Evaporation; Secondary Electron; Photo-cathode; Electron Scattering; Energy Loss Function; Single Particle Imaging; X-ray Diffraction; Water; Ice; KI; CsI; Molekylär biofysik;

   Sammanfattning : X-ray lasers bring us into a new world in photon science by delivering extraordinarily intense beams of x-rays in very short bursts that can be more than ten billion times brighter than pulses from other x-ray sources. These lasers find applications in sciences ranging from astrophysics to structural biology, and could allow us to obtain images of single macromolecules when these are injected into the x-ray beam. LÄS MER

5. 14. 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. 15. 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