Search for dissertations about: "ion velocity"

Showing result 1 - 5 of 63 swedish dissertations containing the words ion velocity.

  2. 1. Plasma environment of an intermediately active comet : Evolution and dynamics observed by ESA's Rosetta spacecraft at 67P/Churyumov-Gerasimenko

    Author : Elias Odelstad; Anders Eriksson; Andrew Coates; Uppsala universitet; []
    Keywords : Rosetta; comet; 67P; RPC-LAP; RPC-MIP; RPC-ICA; RPC-MAG; ROSINA-COPS; Langmuir probe; spacecraft potential; plasma; Churyumov-Gerasimenko; ion composition analyzer; diamagnetic cavity; ion velocity; electron temperature; ion-neutral drag; collisional coupling; wake effects; filamentation; electron cooling; plasma waves; hybrid waves; Bernstein waves; minimum variance; polarization; wavelet; density fluctuations; magnetic field oscillations; drift-cyclotron instability; asymmetric plasma and magnetic field enhancements; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Abstract : The subject of this thesis is the evolution and dynamics of the plasma environment of a moderately active comet before, during and after its closest approach to the Sun. For over 2 years in 2014-2016, the European Space Agency’s Rosetta spacecraft followed the comet 67P/Churyumov-Gerasimenko at distances typically between a few tens and a few hundred kilometers from the nucleus, the longest and closest inspection of a comet ever made. READ MORE

  4. 2. A study of the structure and dynamics of Saturn's inner plasma disk

    Author : Mika Holmberg; Jan-Erik Wahlund; Nikolai Piskunov; Svetlana Ratynskaia; Thomas Cravens; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Planetary magnetospheres; Saturn; magnetospheric dynamics; Saturn s inner plasma disk; ring plasma; ion densities; ion velocities; dayside nightside asymmetry; ion loss rates; Cassini; Langmuir probe; RPWS; Space Physics; Rymdfysik;

    Abstract : This thesis presents a study of the inner plasma disk of Saturn. The results are derived from measurements by the instruments on board the Cassini spacecraft, mainly the Cassini Langmuir probe (LP), which has been in orbit around Saturn since 2004. READ MORE

  5. 3. Near-ambient pressure velocity map imaging

    Author : Tzu-En Chien; Dan Harding; Klas Engvall; Rainer Beck; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Catalyst; Surface reaction; Near-ambient pressure; CO; CO2; CO oxidation; Pd; Palladium; Instrument design; Velocity-map imaging; Katalysator; Ytreaktion; Näraomgivningstryck; CO; CO2; CO oxidation; Pd; Palladium; Instrumentdesign; Hastighetskartbildning; Chemical Engineering; Kemiteknik;

    Abstract : Catalytic reactions on solid surfaces have been studied under Ultra-high vacuum (UHV) conditions for decades. These studies provide crucial information for catalytic reactions, such as surface structures, adsorption sites, and reaction mechanisms. READ MORE

  6. 4. Case Studies in Ion Beam Assisted Nanostructure Engineering

    Author : Rajdeep Kaur; Petter Ström; Daniel Primetzhofer; Tuan Tran; Naureen Ghafoor; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ion irradiation; material modification; nanostructures; calcium fluoride; polyimide; etching; Fysik; Physics;

    Abstract : Beams of energetic ions can be used for material analysis and modification. It provides us with a tool featuring unique control over the area, depth and amount of damage in the material. This property of ion beams can be used to generate desired changes in material properties or form nanostructures with specific characteristics in the material. READ MORE

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

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

    Abstract : 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. READ MORE