Sökning: "free electron model"

Visar resultat 1 - 5 av 21 uppsatser innehållade orden free electron model.

  1. 1. Effects of Ultrafast Ionization in X-ray Coherent Diffraction Imaging

    Master-uppsats, KTH/Kemi

    Författare :Arezu Sehati; [2023]
    Nyckelord :Coherent Diffraction Imaging; X-ray Free Electron Lasers; Refractive index; Core-shell nanoclusters; Rare-gas ionization; Koherent Diffraktionsavbildning; Röntgenfrielektronlaser; Brytningsindex; Core-shell-nanokluster; Ädelgasjonisering;

    Sammanfattning : Koherent Diffraktionsavbildning med en intensiv röntgenpuls från en Frielektronlaser har möjliggjort strukturbestämning av isolerade nanopartiklar som inte går att studera med hjälp av konventionella metoder, så som elektronmikroskopi. En mycket kort pulslängd tillsammans med spridningssignalens beroende av objektets elektroniska struktur medför också möjligheten att studera inducerad ultrasnabb dynamik med denna teknik. LÄS MER

  3. 2. A Machine Learning Approach on Analysis of Emission Spectra for Application in XFEL Experiments

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Institutionen för fysik och astronomi

    Författare :Harald Agelii; [2023]
    Nyckelord :Structural biology; Machine learning; Neural networks; emission spectrum; XFEL; X-ray free electron laser; SFX; Serial femtosecond X-ray crystallography; Proteins; Diagnostics;

    Sammanfattning : In this thesis we investigate two potential applications of machine learning in the context of X-ray imaging and spectroscopy of biological samples, particularly such using X-ray free electron lasers (XFEL). We first investigate the possibility of using an emission spectrum, recorded from a sample after being probed by an incident X-ray, as a diagnostic tool. LÄS MER

  4. 3. Electron-skyrmion systems, in and out of equilibrium, and isolated or contacted to reservoirs

    Magister-uppsats, Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionen

    Författare :Emil Adam Jonatan Östberg; [2023]
    Nyckelord :skyrmion; skyrmions; NEGF; freen s function; quantum transport; non-equlibrium; topology; topological charge; skyrmionics; current induced; open system; Physics and Astronomy;

    Sammanfattning : A Kondo lattice skyrmion model in contact with a macroscopic environment is simulated to explore skyrmion dynamics, which is an extension of previous work. The system is simulated using non-equilibrium Green's functions within the generalized Kadanoff-Baym ansatz and the wide band limit. LÄS MER

  5. 4. 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

  7. 5. Double-layer vs single-layer cryogels as a dye affinity chromatography column, comparison study

    Master-uppsats, Lunds universitet/Kemiska institutionen

    Författare :Thi Hoai Thu Trinh; [2022]
    Nyckelord :dye-affinity chromatography; single-layer cryogels; double-layer cryogels; protein purification; bovine serum albumin; biochemistry; Chemistry;

    Sammanfattning : Dye affinity chromatography is one of the chromatography techniques which uses dye as a ligand for protein purification. In this study, single-layer poly(acrylamide-allyl glycidyl ether) cryogel was prepared, which contains free epoxy groups at sub-zero temperature. LÄS MER