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Showing result 1 - 5 of 73 essays matching the above criteria.

  1. 1. Generation of attosecond X-ray pulses in free-electron lasers using electron energy modulation and undulator tapering

    University essay from Uppsala universitet/FREIA

    Author : Karl-Fredrik Boholm Kylesten; [2023]
    Keywords : attosecond; free-electron laser; XFEL; self-amplified spontaneous emission; SASE; tapering; energy modulation;

    Abstract : Free-electron lasers (FELs) are among the world's most intense artificial artificial sources of coherent light and are tunable to various wavelengths, including the X-ray spectrum. X-ray FELs (XFELs) are extremely useful for diffraction experiments to study molecules, materials, and quantum systems. READ MORE

  3. 2. Spectral broadening of 4 mJ femtosecond pulses using a bulk multi-pass cell

    University essay from Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Author : Saga Westerberg; [2023]
    Keywords : Lasers; Ultrashort; Nonlinear Optics; femtosecond; Multi-Pass Cell; Spectral broadening; pulse post-compression; Self phase modulation; Physics and Astronomy;

    Abstract : Nonlinear optical effects can be used for spectral broadening, which the basis of the field of post-compression of laser pulses. When the intensity of light becomes high enough the refractive index becomes intensity dependent, and as the intensity often varies both with position and time so does the refractive index. READ MORE

  4. 3. Study of vector control strategy on Interior Permanent Magnet Synchronous Motors

    University essay from Högskolan Väst/Institutionen för ingenjörsvetenskap

    Author : Prabhu Bernard; [2023]
    Keywords : Direct Torque Control; IPMSM; implementation; performance;

    Abstract : This thesis presents a comprehensive study of Direct Torque Control (DTC) for Interior Permanent Magnet Synchronous Motors (IPMSMs) evaluating its potential in high performance motor drive systems. The research begins with a literature review, looking into the fundamental principles of DTC, Pulse Width Modulation (PWM), Space Vector Modulation (SVM) and Field Oriented Control (FOC). READ MORE

  5. 4. A Novel Two-Level Inverter Design for Efficient Energy Conversion in a Maglev Train Rail

    University essay from Högskolan i Halmstad/Akademin för informationsteknologi

    Author : Oskar Zetterström; Stefan West Westholm; [2023]
    Keywords : IGBT; Inverter; Gate-driver; Prototype; Pulse width modulation; Sine wave; Maglev train; IGBT; Växelriktare; Grinddrivenhet; Prototyp; Pulsbreddsmodulering; Sinusvåg; Maglevtåg;

    Abstract : This report covers the construction of a prototype inverter system designed to power the rail of a maglev train, from component selection through simulations and power demands to mounting and wiring the components into a cabinet. The inverter is made with insulated gate bipolar transistors controlled with pulse-width modulated signals provided by a custom microcontroller. READ MORE

  6. 5. Focal Spot Optimization Using Spatial Light Modulation and a Phase Retrieval Algorithm

    University essay from Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Author : Robert Petersen; [2023]
    Keywords : Spatial Light Modulation; Phase Retrieval Algorithm; Focal Spot Optimization; Adaptive Optics; Wavefront Sensing; Lasers; Physics and Astronomy; Technology and Engineering;

    Abstract : Aberrations to the wavefront of a laser beam reduce the quality of the focal spot and are generally undesired. This project is aimed at determining the aberrations of laser beams by using a phase retrieval algorithm and to show that it is possible to correct the aberrations with a spatial light modulator to optimize the focal spot. READ MORE