Sökning: "Atomic Physics"

Visar resultat 11 - 15 av 661 avhandlingar innehållade orden Atomic Physics.

  1. 11. Effect of Substrate on Bottom-Up Fabrication and Electronic Properties of Graphene Nanoribbons

    Författare :Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; graphene nanoribbons; bottom-up; substrate; metal contact; electronic structure; electron doping; PES; ARPES; NEXAFS; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Taking into account the technological demand for the controlled preparation of atomically precise graphene nanoribbons (GNRs) with well-defined properties, the present thesis is focused on the investigation of the role of the underlying metal substrate in the process of building GNRs using bottom-up strategy and on the changes in the electronic structure of GNRs induced by the GNR-metal interaction. The combination of surface sensitive synchrotron-radiation-based spectroscopic techniques and scanning tunneling microscopy with in situ sample preparation allowed to trace evolution of the structural and electronic properties of the investigated systems. LÄS MER

  2. 12. Extreme Electron Beams and Brilliant X-rays : Generation, Manipulation and Characterization of Relativistic Electron Beams for and from Plasma-Based Accelerators

    Författare :Jonas Björklund Svensson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; wakefield; acceleration; accelerator; relativistic; electrons; x-rays; ultra-fast; betatron; laser-wakefield acceleration; plasma-wakefield acceleration; Fysicumarkivet A:2020:Björklund;

    Sammanfattning : This thesis is based on work done by the author on the development of plasma-based electron accelerators driven by ultra-intense laser pulses and dense electron bunches. Plasma based accelerators have several benefits, such as accelerating fields around 1000 times stronger than in “conventional” radio-frequency accelerators, which can allow for shrinking the overall footprint of the accelerator. LÄS MER

  3. 13. Precision Improvements of Penning Trap Mass Measurements Using Highly Charged Ions : Applications to solving current problems in fundamental physics

    Författare :Tomas Fritioff; Reinhold Schuch; Jürgen Kluge; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; Atom- och molekylfysik; Physics; fysik;

    Sammanfattning : In my thesis I describe the improvements of the Penning trap mass spectrometer SMILETRAP. The objective of these improvements have been to increase the reliability and the accuracy with which an atomic mass can be measured using highly charged ions. LÄS MER

  4. 14. Development of laser spectroscopy for scattering media applications

    Författare :Mats Andersson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laserteknik; Laser technology; Atom- och molekylärfysik; Atomic and molecular physics; Fysik; Physics; coherent sampling; optical sensor; light absorption; noninvasive measurement; diode laser; scattering of light; laser spectroscopy; fluorescence spectroscopy; remote sensing; Lidar; DIAL;

    Sammanfattning : Laser spectroscopy for both large and small spatial scales has been developed and used in various applications ranging from remote monitoring of atmospheric mercury in Spain to investigation of oxygen contents in wood, human sinuses, fruit, and pharmaceutical solids. Historically, the lidar group in Lund has performed many differential absorption lidar (DIAL) measurements with a mobile lidar system that was first described in 1987. LÄS MER

  5. 15. Laser Spectroscopy in Scattering Media for Biological and Medical Applications

    Författare :Linda Persson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Instrumentation technology; Mät- och instrumenteringsteknik; Atom- och molekylärfysik; Atomic and molecular physics; Fysik; Physics; Monte Carlo simulations; Biomedical Optics; Scattering media; Gas measurements; Near infrared spectroscopy; Diode laser spectroscopy; Absorption spectroscopy;

    Sammanfattning : Tunable diode laser absorption spectroscopy can be utilised for gas detection in biological and medical applications. The common approach is to analyse transmitted light according to the Beer-Lambertian law. LÄS MER