Sökning: "electronic excitation"

Visar resultat 1 - 5 av 227 avhandlingar innehållade orden electronic excitation.

  1. 1. Electronic excitation, luminescence and particle emission : Studying ion-induced phenomena in ToF-MEIS

    Författare :Svenja Lohmann; Daniel Primetzhofer; Friedrich Aumayr; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TOF-MEIS; ion beam analysis; deep UV; desorption; electronic sputtering; TiN;

    Sammanfattning : Medium energy ion scattering (MEIS) is an experimental technique for the high-resolution depth profiling of thin films. Commonly, ions with energies between several ten to a few hundred keV are employed as probes, and backscattered particles are detected. LÄS MER

  3. 2. Photoelectron Spectroscopy on Atoms, Molecules and Clusters : The Geometric and Electronic Structure Studied by Synchrotron Radiation and Lasers

    Författare :Torbjörn Rander; Olle Björneholm; Gunnar Öhrwall; Maxim Tchaplyguine; Matthias Neeb; Uppsala universitet; []
    Nyckelord :Atomic and molecular physics; Free clusters; Electron spectroscopy; Doped clusters; Laser excitation; Alkali metals; Electronic structure; Geometric structure; X-ray photoelectron spectroscopy XPS ; Resonant Auger spectroscopy RAS ; Near-threshold x-ray absorption fine structure NEXAFS ; Ultraviolet photoelectron spectroscopy UPS ; Detuning; Ultra-fast dissociation UFD ; Sodium; Potassium; Oxygen; Bromomethane; Argon; Xenon; Krypton; Molecular field splitting; Core hole lifetime; Core excitation; Atom- och molekylfysik;

    Sammanfattning : Atoms, molecules and clusters all constitute building blocks of macroscopic matter. Therefore, understanding the electronic and geometrical properties of such systems is the key to understanding the properties of solid state objects. LÄS MER

  4. 3. Synchronous Machines with High-Frequency Brushless Excitation for Vehicle Applications

    Författare :Junfei Tang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrically Excited Synchronous Machines; Machine Modeling; Brushless Excitation; Machine Control; Machine Design; Electric Vehicles;

    Sammanfattning : Electrically excited synchronous machines (EESM) are becoming an alternative to permanent magnet synchronous machines (PMSM) in electric vehicle (EV) applications. This mainly attributes to the zero usage of rare-earth material as well as the capabilities of high starting torque and good field weakening provided by EESM. LÄS MER

  5. 4. Hydropower generator and power system interaction

    Författare :Johan Bladh; Urban Lundin; Rafael Escarela-Perez; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Amortisseur windings; applied voltage test; automatic voltage regulators; damper windings; damping torque; empirical modelling; equivalent circuits; excitation control; finite element method; hydropower generators; power system restoration; power system stability; synchronous machines; self excitation; shaft torque amplification; short circuit test; single machine infinite bus; slip test; standstill frequency response test; subsynchronous oscillations; synchronising torque; synchronous generators; torsional interaction.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : After decades of routine operation, the hydropower industry faces new challenges. Large-scale integration of other renewable sources of generation in the power system accentuates the role of hydropower as a regulating resource. LÄS MER

  7. 5. Fast-response rotating brushless exciters for improved stability of synchronous generators

    Författare :Jonas Kristiansen Nøland; Urban Lundin; Oskar Wallmark; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synchronous generators; permanent magnet machines; excitation systems; power electronic interfaces; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : The Norwegian Network Code FIKS from the Norwegian Transmission System Operator (TSO) Statnett, states that synchronous generators ≥ 25 MVA must have a static excitation system. It also includes requirements on the step time response and the available field winding ceiling voltage of the excitation system. LÄS MER