Sökning: "electron cloud"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden electron cloud.

  1. 1. Low Secondary Electron Yield Carbon Coatings for Electron Cloud Mitigation in Modern Particle Accelerators

    Författare :Christina Yin Vallgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Raman spectroscopy; NRA; amorphous carbon; secondary electron yield; LIU; X-Ray Photoelectron Spectroscopy; SEY; AFM; electron cloud; SPS dipole magnet;

    Sammanfattning : In order to upgrade the Large Hadron Collider (LHC) performance to be oriented towards higher energies and higher intensities in the future, a series of improvementsof the existing LHC injectors is planned to take place over the next few years. Electron cloud effects are expected to be enhanced and play a central role in limiting theperformance of the machines of the CERN complex. LÄS MER

  3. 2. Electron-lattice dynamics in π-conjugated systems

    Författare :Magnus Hultell (Andersson); Sven Stafström; Alessandro Troisi; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; charge transport; electron-lattice dynamics; polaron; adiabatic transport; electron localization; internal conversion; Computational physics; Beräkningsfysik;

    Sammanfattning : The work presented in this thesis concerns the dynamics in π-conjugated hydrocarbon systems. Due to the molecular bonding structure of these systems there exists a coupling between the electronic system and the phonons of the lattice. LÄS MER

  4. 3. The high Arctic summer aerosol : Size, chemical composition, morphology and evolution over the pack-ice

    Författare :Evelyne Hamacher-Barth; Caroline Leck; Stephan Weinbruch; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; aerosol; marine gel; electron microscopy; EDX-spectroscopy; chemical composition; morphology; size distribution; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : Aerosol particles, especially in the high Arctic are still not very well represented in climate models. Particle size and number concentrations are strongly under-predicted and temporal variations of aerosol composition and size are still not very well understood, mainly due to the sparsity of observations. LÄS MER

  5. 4. Dynamics and Structure of Negative Ions - Photoinduced double detachment on nano- and femtosecond time scales

    Författare :Hannes Hultgren; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The goal of the presented work is to investigate double detachment of negative ions on nano- and femtosecond time scales. I have performed three types of experiments. Femtosecond time resolved pump-probe experiments have been performed on electron dynamics in the valence shell of carbon, silicon and germanium atoms. LÄS MER

  7. 5. Analytical and Numerical Developments in Strongly Correlated Systems: Perspectives from TDDFT and Green's Functions

    Författare :Daniel Karlsson; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Many-Body Perturbation Theory; Hubbard model; TDDFT; Green s function; DFT; Quantum Transport; Disorder; Fysicumarkivet A:2014:Karlsson;

    Sammanfattning : This thesis investigates different methods for treating strongly correlated systems, and discusses their respective strengths and weaknesses. Many of the results presented in this thesis come from comparing the different methods and approximations to exact results. LÄS MER