Sökning: "UHV"

Visar resultat 1 - 5 av 42 avhandlingar innehållade ordet UHV.

  1. 1. Symmetric scanning tunneling microscopes for ultra high vacuum and very low temperatures

    Författare :Per Anders Davidsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stability; scanning; single crystal; LTTM; VLTTM; tunneling microscope; UHV; dilution refrigator; piezoelectric;

    Sammanfattning : .... LÄS MER

  3. 2. Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution : The Development of Experimental Equipment for Extreme Ultraviolet Spectroscopy

    Författare :Joachim A. Terschlüsen; Johan Söderström; Margaret Murnane; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Angle-resolved photoemission spectroscopy; Angle resolved photoemission spectroscopy; Angle-resolved time-of-flight; Angle resolved time of flight; ARTOF; ARPES; tr-ARPES; fs; fs resolution; Fourier transform spectrometer; Fourier-transform spectrometer; Fourier transform spectroscopy; Fourier-transform spectroscopy; FTS; gas cell; high harmonic generation; laser; liquid jet; monochromator; HELIOS; HHG; off-plane mount; off plane mount; OPA; optical parametric amplifier; PCPDTBT; pulse shaping; pump probe; pump-probe measurements; pump-probe measurements; pump-probe spectroscopy; pump-probe spectroscopy; Rowland spectrometer; time-of-flight spectrometer; time of flight spectrometer; TOF; time-resolved spectroscopy; time resolved spectroscopy; time-resolved experiments; time resolved experiments; T-MOKE; tr-PES; PES; photoelectron spectroscopy; transverse magneto optical Kerr effect; transverse magneto-optical Kerr effect; ultrafast; ultra-high vacuum; ultra high vacuum; UHV; XUV; VUV; X-rays; Permalloy; magnetization dynamic; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : This thesis presents HELIOS, an in-house laboratory for time-resolved pump-probe spectroscopy with extreme-ultraviolet (XUV) probe radiation. A wide span of pump wavelengths can be generated using commercial laser equipment while XUV probe radiation is generated via a high harmonic generation process in a noble gas delivering probe photons with energies between 20 eV and 72 eV. LÄS MER

  4. 3. UHV-CVD growth of Ge/Si nanostructures

    Författare :Vilma Zela; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiconductory physics; Fysik; Physics; Naturvetenskap; Si; Ge; Esaki diode; Halvledarfysik; Ge layer; Natural science; Ge Ilands; posiotioning;

    Sammanfattning : This thesis is based on the results concerning the epitaxial growth and characterization of silicon (Si) and germanium (Ge) nanostructures. The growth technique was the Ultra High Vacuum Chemical Vapor Deposition (UHV-CVD) that works in relatively low temperatures and low growth pressures. LÄS MER

  5. 4. Redox Reactions of Uranium-Based Materials in Aqueous Systems and Under UHV Conditions. : Two models mimicking radiation-induced oxidation of spent nuclear fuel

    Författare :Ghada El Jamal; Mats Jonsson; Christophe Jégou; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kemi; Chemistry;

    Sammanfattning : The demand for clean electricity is a primary concern in Europe. Nuclear power isconsidered as a greenhouse gas-free technology for generation of electricity. However,compared to other energy sources, it generates a highly toxic waste.In Sweden, the long-term solution for the waste disposal issue is called the KBS-3 method. LÄS MER

  7. 5. Oxidation of some Late Transition Metal Surfaces: Structural Studies from UHV to Atmospheric Pressure

    Författare :Johan Gustafson; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kondenserade materiens egenskaper:struktur; phase equilibria; crystallography; thermal and mechanical properties; Condensed matter:stucture; density functional theory; scanning tunneling microscopy; surface x-ray diffraction; high resolution core level spectroscopy; low energy electron diffraction; metal surfaces; oxidation; catalysis; egenskaper termiska och mekaniska ; kristallografi; fasjämvikt;

    Sammanfattning : The oxidation of Rh, Pd and Pt is studied under conditions ranging from ultra high vacuum to ambient pressures, with emphasis on a complete understanding of the geometry of the various oxide structures found. The investigations use a combination of various experimental methods, including high resolution core level spectroscopy, low energy electron diffraction, surface x-ray diffraction and scanning tunneling microscopy, as well as density functional theory calculations. LÄS MER