Sökning: "supersonic"

Visar resultat 11 - 15 av 41 avhandlingar innehållade ordet supersonic.

  1. 11. Experiments on Laser-Based Particle Acceleration : Beams of Energetic Electrons and Protons

    Författare :Kristoffer Svensson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; acceleration; electrons; protons; Fysicumarkivet A:2016:Svensson;

    Sammanfattning : This thesis describes experiments involving laser-plasma-based acceleration of electrons and protons, using the techniques of laser wakefield acceleration (LWFA) and target normal sheath acceleration (TNSA). By using extremely high accelerating field strengths, up to the order of TV m-1, it is possible to reach high kinetic particle energies over very short distances. LÄS MER

  3. 12. Analytical Electron Microscopy Studies for Development of New Carbon Based Materials

    Författare :Staffan Wachtmeister; Stefan Csillag; Gilles Hug; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEM; EELS; CNx thin films; Carbide derived carbons; Gold deconvolution; Resolution improvement; Physics; Fysik; fysik; Physics;

    Sammanfattning : The thesis presents transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) studies of new carbon based materials synthesized with two different techniques. In the first project, nitrogen is incorporated into carbon nanostructures by supersonic cluster beam deposition (SCBD) to favor the formation of curved and cross-linked structures, ultimately aiming at creating a material with high hardness combined with good elasticity. LÄS MER

  4. 13. Ion dynamics and structure of collisionless shocks in space

    Författare :Andreas Johlander; Andris Vaivads; Robert F. Wimmer-Schweingruber; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : Shock waves form when supersonic flows encounter an obstacle. Like in regular gases, shock waves can form in a plasma - a gas of electrically charged particles. Shock waves in plasmas where collisions between particles are very rare are referred to as collisionless shock waves. LÄS MER

  5. 14. Electron-transfer processes in fast ion-atom collisions

    Författare :Kristian Støchkel; Henning Schmidt; Henrik Cederquist; Andreas Wolf; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electron transfer processes fast ion atom collisions hydrogen helium; Atomic and molecular physics; Atom- och molekylfysik;

    Sammanfattning : The subject of this thesis is experimental studies of electron-transfer processes in ion-atom collisions at velocities significantly higher than typical orbital velocities of electrons in bound states of atoms or molecules. The experimental technique applied combines the high beam intensity of heavy-ion storage rings with a supersonic gas-jet target equipped with a recoil-ion-momentum spectrometer. LÄS MER

  7. 15. Flame Dynamics and Deflagration-to-Detonation Transition

    Författare :Damir Valiev; Börje Johansson; R. J. M. (Rob) Bastiaans; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; flame; premixed; instability; fractal; deflagration; detonation; DDT; simulation; Physics; Fysik;

    Sammanfattning : Various premixed flame phenomena are studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics is essential for all premixed combustion problems where multidimensional effects cannot be disregarded.The present thesis consists of six parts. LÄS MER