Sökning: "momentum probe"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden momentum probe.

  1. 1. Fluid Dynamics of the Transport Zone of Circulating Fluidized Beds - with Application to Boilers

    Författare :Wennan Zhang; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid dynamics; particle flux probe; momentum probe; circulating fluidized bed boilers; circulating fluidized beds; particle flow pattern; particle concentration probe; spectrum analysis;

    Sammanfattning : The particle suspension flow structure in circulating fluidized beds (CFB) was studied with emphasis on the layer of downflowing particles at the wall. The main experiments were carried out in the furnace of the 12 MWth CFB boiler of 1.7x1.7 m cross-section, and in a two-dimensional CFB cold bed of 0. LÄS MER

  3. 2. Short Attosecond Pulse Trains at High Repetition Rates for Novel Pump-Probe and Coincidence Studies

    Författare :Sara Mikaelsson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond; High-Order Harmonic Generation; Photoionization; Attosecond; High-Order Harmonic Generation; Photoionization; Fysicumarkivet A:2021:Mikaelsson;

    Sammanfattning : This work aims at studying photoionization dynamics from atoms and surfaces at attose time scales. The work was based on development and applications of a high repetition rate High-order Harmonic Generation (HHG) light source that utilizes Optical Parametric Amplification (OPA) laser technology. LÄS MER

  4. 3. Ultrafast Spectroscopy of Atomic and Molecular Quantum Dynamics

    Författare :Pia Johansson; Tony Hansson; Bertrand Girard; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical physics; Kemisk fysik;

    Sammanfattning : An all-pervading feature of the work presented in this thesis is the study of ultrafast dynamics, both theoretically and experimentally, in terms of time-dependent wave functions (wave packets).We have experimentally, by pump-probe fluorescence spectroscopy, examined spin-orbit interactions, by time-tracing molecular wave packets on excited states of diatomic rubidium, and the main channels causing the fast predissociation from one of those states is revealed. LÄS MER

  5. 4. Microscopic Theory of Exciton Dynamics in Two-Dimensional Materials

    Författare :Samuel Brem; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; exciton-phonon interaction; van der Waals materials; relaxation dynamics; excitons; 2D materials; density matrix formalism;

    Sammanfattning : Transition Metal Dichalcogenides (TMDs) present a giant leap forward towards the realization of nanometer-sized quantum devices. As a direct consequence of their truly two-dimensional character, TMDs exhibit a strong Coulomb-interaction, leading to the formation of stable electron-hole pairs, so-called excitons. LÄS MER

  7. 5. Atomic and Molecular Dynamics Probed by Intense Extreme Ultraviolet Attosecond Pulses

    Författare :Jasper Peschel; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond science; Ultrafast phenomena; High-order Harmonics Generation; Free Electron Lasers; Photoionization; Photodissociation; Fysicumarkivet A:2021:Peschel;

    Sammanfattning : This thesis work was aimed to investigate dynamical processes in atoms and molecules on ultrafast time scales initiated by absorption of light in the extreme ultraviolet (XUV) regime. In particular, photoionization and photodissociation have been studied using pump-probe techniques involving ultrafast laser pulses. LÄS MER