Sökning: "Single electron source"

Visar resultat 16 - 20 av 90 avhandlingar innehållade orden Single electron source.

1. 16. Flash Diffractive Imaging in Three Dimensions

   Författare :Tomas Ekeberg; Janos Hajdu; Keith Nugent; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray; diffraction; mimivirus; three dimensional; phase retrieval; EMC; manifold embedding; CXI; FEL; free-electron laser; single particle; Physics with specialization in Biophysics; Fysik med inriktning mot biofysik;

   Sammanfattning : During the last years we have seen the birth of free-electron lasers, a new type of light source ten billion times brighter than syncrotrons and able to produce pulses only a few femtoseconds long. One of the main motivations for building these multi-million dollar machines was the prospect of imaging biological samples such as proteins and viruses in 3D without the need for crystallization or staining. LÄS MER

3. 17. Towards ultrafast imaging with extreme ultraviolet light sources

   Författare :Jörg Schwenke; Lunds universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photo emission electron microscopy; Focusing of X-ray radiation; Digital holography; High-order harmonic generation; Free-electron laser seeding; Secondary electron cascades; Fysicumarkivet A:2012:Schwenke;

   Sammanfattning : This thesis reports experimental studies performed with two advanced coherent XUV sources with ultrashort pulse duration, high-order harmonic generation and seeded-free electron laser. High-order harmonic generation (HHG) is the generation of overtones of a fundamental laser pulse in a medium, e.g. noble gases. LÄS MER

4. 18. Attosecond interferometry: techniques and spectroscopy

   Författare :David Kroon; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysicumarkivet A:2016:Kroon; Electron wave packet; Attosecond Pulse trains; Photoionization; Photoemission time delay; High-order harmonic generation; Interferometry; Electron dynamics;

   Sammanfattning : The interaction between an intense laser pulse and a gas medium leads to the emission of coherent bursts of light in the extreme ultraviolet range. This process, known as high-order harmonic generation, has today, almost three decades after its discovery, developed into a reliable source of extremely short (on the order of 100 as) pulses of electromagnetic radiation, with a wide range of applications in the atomic, molecular and optical sciences. LÄS MER

5. 19. Electron beam-powder bed fusion of Alloy 718 : Effect of process parameters on microstructure evolution

   Författare :Paria Karimi Neghlani; Joel Andersson; Joakim Ålgårdh; Iain Todd; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Additive manufacturing; Electron beam-powder bed fusion; Microstructure evolution; Microstructure tailoring; Process understanding; Alloy 718; Production Technology; Produktionsteknik;

   Sammanfattning : Additive manufacturing (AM) is the technology of building 3D parts through layer-by-layer addition of material. Of the different types of AM techniques, electron beam-powder bed fusion (EB-PBF) has been used in this study. EB-PBF can build parts by melting metallic powders using an electron beam as the energy source. LÄS MER

7. 20. Experimental and theoretical investigations of electron-waveguide devices

   Författare :Jan-Olof Wesström; KTH; []
   Nyckelord :;

   Sammanfattning : This thesis treats electron-waveguide devices bothexperimentally and theoretically. A fabrication method forelectron-waveguide devices with trench-isolated in plane gateswas developed in the In0.53Ga0.47As/InP material system. LÄS MER