Search for dissertations about: "Chopper"

Showing result 1 - 5 of 8 swedish dissertations containing the word Chopper.

  2. 1. On the Challenges for Time-of-Flight Electron Spectroscopy at Storage Rings

    Author : Christian Stråhlman; Lunds universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; time-of-flight; photoelectron spectroscopy; MAX IV; storage ring; detector gating; chopper; coincidence spectroscopy;

    Abstract : Time-of-flight (TOF) techniques for energy analysis have been common in electron spectroscopy for many decades. TOF-based electron spectrometers benefit from higher transmission and information rate compared to their main competitor: the hemispherical analyser; the drawback being their lower energy resolution. READ MORE

  4. 2. A New Paradigm for Large Brushless Hydrogenerators : Advantages Beyond the Static System

    Author : Jonas Kristiansen Nøland; Urban Lundin; Phil Mellor; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brushless exciters; Rotating exciters; Permanent Magnet Machines; Synchronous Generator Excitation; Thyristor Rectifiers; Chopper Rectifiers; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : The grid code, FIKS, from the Norwegian transmission system operator (TSO), Statnett, states that synchronous generators > 25MVA, must have a static excitation system. However, an improved brushless excitation system is in operation on some commercial power plants (36MVA, 93.75rpm & 52MVA, 166. READ MORE

  5. 3. Techniques and Application of Electron Spectroscopy Based on Novel X-ray Sources

    Author : Stefan Plogmaker; Hans Siegbahn; Håkan Rensmo; Emma Springate; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; High Harmonic Generation HHG; HELIOS; X-ray Beam Chopper; Dye-sensitized Solar Cell; Ultra High Vacuum UHV; Photoelectron Spectroscopy; Pump-Probe; XUV; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : The curiosity of researchers to find novel characteristics and properties of matter constantly pushes for the development of instrumentation based on X-radiation. I present in this thesis techniques for electron spectroscopy based on developments of X-ray sources both in time structure and energy. READ MORE

  6. 4. Design and Implementation of RF Kickers in MAX IV

    Author : David Olsson; Lunds universitet; []
    Keywords : Accelerator cavities; Beam choppers; Bunch-by-bunch feedback; RF kickers; Striplines;

    Abstract : The MAX IV facility in Lund, Sweden, consists of two storage rings for production of synchrotron radiation, and a full-energy LINAC for top-up injections. The LINAC also delivers short high-intensity electron bunches to a short pulse facility. READ MORE

  7. 5. Fault Behavior of Wind Turbines

    Author : Francesco Sulla; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Turbines; Short-Circuit Currents; Doubly-Fed Induction Generator; Grid Fault Ride-Through; Voltage Support; Weak Grid;

    Abstract : Synchronous generators have always been the dominant generation type in the grid. This fact affected both planning and operation of power systems. With the fast increase of wind power share in the grid in the last decade, the situation is changing. In some countries wind power represents already a consistent amount of the total generation. READ MORE