Sökning: "X-ray free-electron lasers"
Visar resultat 11 - 15 av 36 avhandlingar innehållade orden X-ray free-electron lasers.
11. Ultrafast spin dynamics at the nanoscale : using coherent X-ray and terahertz radiation
Sammanfattning : The field of ultrafast magnetism is driven by the growing need for faster and more efficient magnetic data storage, which comprises the vast majority of the digital information worldwide. However, after more than two decades of intense research, the understanding of the fundamental physical processes governing the transfer of angular momentum necessary for magnetic switching, is still lacking, partially hampered by the appropriate experimental tools. LÄS MER
12. Efficiency Enhancement Techniques for Free-Electron Lasers
Sammanfattning : The central question addressed in this thesis is how to make the free-electron laser (FEL) more efficient. In recent years, coherent diffraction imaging provides an important motivation for efficiency enhancement. This is because a more efficient FEL process enables converting a larger fraction of the electron beam's power into optical power. LÄS MER
13. Simulations of ultrafast photon-matter interactions for molecular imaging with X-ray lasers
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
14. Ultrafast Coherent X-ray Diffractive Nanoimaging
Sammanfattning : X-ray lasers are creating unprecedented research opportunities in physics,chemistry and biology. The peak brightness of these lasers exceeds presentsynchrotrons by 1010, the coherence degeneracy parameters exceedsynchrotrons by 109, and the time resolution is 105 times better. LÄS MER
15. Probing and improving coherence in Free-electron lasers
Sammanfattning : Free electron lasers or FELs, have transformed the way science has been done in the last decades by providing coherent, highly brilliant radiation at wavelengths not achievable with conventional lasers. Their most important characteristic, along side brightness, is their coherence, which allows users to perform experiments that rely on precise phase characteristics of the probing radiation. LÄS MER