Search for dissertations about: "aligned currents"

Showing result 1 - 5 of 14 swedish dissertations containing the words aligned currents.

  2. 1. Investigations of auroral electric fields and currents

    Author : Tommy Johansson; Göran Marklund; Kristina Lynch; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; auroral physics; auroral electric fields; auroral potential structures; auroral particle acceleration; Space physics; Rymdfysik;

    Abstract : The Cluster spacecraft have been used to investigate auroral electric fields and field-aligned currents (FACs) at geocentric distances between 4 and 7 Re. The electric fields have been measured by the EFW instrument, consisting of two pairs of spherical probes, and the FACs have been calculated from measurements of the magnetic field by the FGM fluxgate magnetometer. READ MORE

  4. 2. Electron beam profile measurements and emittance manipulation at the MAX-laboratory

    Author : Åke Andersson; Lunds universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; optics; quantum excitation; emittance; synchrotron radiation; electron beam; lattice; Accelerator; storage ring; diffraction; Physics; Fysik;

    Abstract : The emittances of the electron beams at the MAX-laboratory accelerator system have been studied. Apart from the build-up of the diagnostic tools for precise determination of the beam spatial profiles, the objectives have been: a) to verify the accelerator design emittances at low currents and to try to determine the emittances also at high currents; b) to investigate possibilities to manipulate the emittances. READ MORE

  5. 3. Plasma and dust interaction in the magnetosphere of Saturn

    Author : Jonas Olson; Svetlana Ratynskaia; Carmine Castaldo; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; saturn; dusty plasma;

    Abstract : The Cassini spacecraft orbits Saturn since 2004, carrying a multitude of instruments for studies of the plasma environment around the planet as well as the constituents of the ring system. Of particular interest to the present thesis is the large E ring, which consists mainly of water ice grains, smaller than a few micrometres, referred to as dust. READ MORE

  6. 4. Auroral Electric Fields From Satellite Observations and Numerical Modelling

    Author : Tomas Karlsson; KTH; []
    Keywords : Satellite measurements; electric fields; ionosphere; magnetosphere; diverging electric fields; downward current region; black aurora; westward travelling surge; auroral bulge; subauroral ion drifts SAID ; subauroral electric fields SAEF ; mid-latit; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : This thesis is about electrodynamics of thehigh-latitude/auroral region of near-Earth space. The work ismainly based on electric field measurements made by the doubleprobe instrument on the Freja satellite at altitudes ofapproximately 800-1700 km, together with measurements fromother instruments on the same satellite, and ground-basedinstrumentation. READ MORE

  7. 5. Field Emission from Multi-walled Carbon Nanotubes and its Application in Nanoelectromechanical Systems

    Author : Martin Sveningsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; nanoelectromechanical systems; electron field emission; Fowler-Nordheim theory; Carbon nanotubes; Ohmic heating;

    Abstract : Films of aligned multi-walled carbon nanotubes (MWCNTs) areinteresting for applications such as cold emission cathodes in flat-panel display technology and in lighting elements. MWCNTs are, besides this, good candidates to be used innanoelectromechanical systems (NEMS). READ MORE