Sökning: "ultra-high vacuum"
Visar resultat 1 - 5 av 69 avhandlingar innehållade orden ultra-high vacuum.
1. 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
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
2. Atomically Resolved ac-Mode Atomic Force Microscopy in Ultra-High Vacuum
Sammanfattning : When the atomic force microscope (AFM) was invented in 1986, it was anticipated that the technique should be able to produce atomically resolved images with aquality similar to what was routinely obtained with the scanning tunnelling microscope (STM). Even though the AFM quickly became a very popular technique, the development toward ultra-high resolution imaging turned out to be slow due to problems of both fundamental and technical nature. LÄS MER
3. Symmetric scanning tunneling microscopes for ultra high vacuum and very low temperatures
Sammanfattning : .... LÄS MER
4. Design and Construction of Low-Temperature Scanning Tunnelling Microscope for Spectroscopy
Sammanfattning : This thesis discusses some of the fundamental requirements needed to be fulfilled when constructing a low temperature scanning tunnelling microscope (STM). Three different designs, two non-vacuum and one ultra-high vacuum (UHV), based on either inertial-mass or novel stepper motor principles are presented. LÄS MER
5. Reactions on nanostructured and microporous surfaces
Sammanfattning : Interactions between surfaces and molecules play a central role in various fields where catalysis is one example. In order to understand different surface processes, physicochemical characterisation of the surface materials and molecules is required. LÄS MER