Sökning: "Coherent Diffraction Radiation"

Hittade 3 uppsatser innehållade orden Coherent Diffraction Radiation.

  1. 1. Generation of attosecond X-ray pulses in free-electron lasers using electron energy modulation and undulator tapering

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/FREIA

    Författare :Karl-Fredrik Boholm Kylesten; [2023]
    Nyckelord :attosecond; free-electron laser; XFEL; self-amplified spontaneous emission; SASE; tapering; energy modulation;

    Sammanfattning : Free-electron lasers (FELs) are among the world's most intense artificial artificial sources of coherent light and are tunable to various wavelengths, including the X-ray spectrum. X-ray FELs (XFELs) are extremely useful for diffraction experiments to study molecules, materials, and quantum systems. LÄS MER

  3. 2. Time-resolved x-ray diffraction study of longitudinal optical phonons in zincblende semiconductors

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Lassi Linnala; [2022]
    Nyckelord :femtosecond THz radiation; ultrafast x-ray diffraction; pump-probe; longitudinal optical phonons; zincblende semiconductors; anharmonic decay; density functional perturbation theory; Physics and Astronomy;

    Sammanfattning : Anharmonic decay of longitudinal optical (LO) phonons in zincblende semiconductors is not at present well characterized due to the polar and many-body nature of the problem. Femtosecond THz radiation offers a novel route to this study, as the interaction of this radiation is directly with the phonon lattice and these THz excited phonons do not have enough energy to excite electrons over the band gap. LÄS MER

  4. 3. A Near-Infrared Diffraction Radiation Spectrometer for MHz Repetition Rate Electron Bunch Diagnostics at the European XFEL

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Tillämpad kärnfysik

    Författare :Simon Fahlström; [2019]
    Nyckelord :European XFEL; XFEL; Free-Electron Laser; FEL; bunch diagnostics; Coherent Diffraction Radiation; Spectrometer;

    Sammanfattning : We have built a spectrometer to investigate the Near-Infrared (NIR) range of this radiation, which is used for bunch diagnostics at the European X-ray Free-Electron Laser. This could give information on the development of microbunching, periodic features in the longitudinal charge profile of the bunches which have a negative impact on the operation of the facility. LÄS MER