Sökning: "0281-2762"

Visar resultat 1 - 5 av 64 avhandlingar innehållade ordet 0281-2762.

  1. 1. Numerical and Experimental Studies of Wakefield Accelerators

    Författare :Henrik Ekerfelt; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; laser wakefield acceleration; betatron radiation; ionization-induced trapping; density down-ramp trapping; colliding pulse injection; direct laser acceleration; laser wakefield merging; particle-in-cell simulations; high-intensity optics; Fysicumarkivet A:2019:Ekerfelt;

    Sammanfattning : This thesis is based on work done by the author on the development of laser wakefield accelerators.Wakefield acceleration in plasmas is a promising technique to provide the next generation of accelerating structures and particle beams. LÄS MER

  3. 2. Generation and metrology of ultrashort pulses and their application in attosecond science

    Författare :Lana Neoricic; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ultrashort; filamentation; femtosecond; dispersion scan; RABBIT; photoionisation; attosecond; interferometry; pump-probe; spectroscopy; photoelectron; wavepacket; Fysicumarkivet A:2022:Neoricic;

    Sammanfattning : This thesis deals with the dynamical processes in atoms and small molecules initiated by the absorption of ultrashort, coherent light pulses. The studied phenomena takeplace on the femtosecond (1 fs = 10−15 s) and attosecond (1 as = 10−18 s) timescales and critically depend on the properties of the light fields that drive them. LÄS MER

  4. 3. Target and Laser Pulse Optimization for Laser-Driven Ion Acceleration

    Författare :Alexander Permogorov; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Terawatt laser; Target normal sheath acceleration; laser-driven ion acceleration; proton acceleration; double plasma mirror; Thomson parabola spectrometer; Fysicumarkivet A:2021:Permogorov;

    Sammanfattning : The research presented in this thesis is primarily focused on experimental investigations of laser-driven ion acceleration from solid targets via the target normal sheath acceleration mechanism. In particular, ways of optimizing the absorption of the laser pulse energy by free plasma electrons in the target, or modifying the shape of the accelerating electron sheath were addressed. LÄS MER

  5. 4. Studies of Phonons and Phase Transitions by Time-Resolved X-ray Diffraction

    Författare :Henrik Enquist; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; synchrotron radiation; ultrashort pulses; material science; phase transition; X-ray diffraction; phonon; X-ray detector;

    Sammanfattning : When light is used to study structures, the wavelength limits the size of the details that can be resolved. Visible light can be used to investigate structures as small as a micrometre in size. To study smaller structures a shorter wavelength is required. LÄS MER

  7. 5. Time-Resolved Spectroscopy for Pharmaceutical Applications

    Författare :Christoffer Abrahamsson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elektromagnetism; optik; Near-infrared spectroscopy; Time-resolved spectroscopy; Pharmaceutical analysis; Multivariate data analysis; Electromagnetism; Light transport in turbid media; Photon migration; akustik; acoustics; optics;

    Sammanfattning : The work presented in this thesis aims at improving spectroscopic techniques for analysis of pharmaceutical solids. This improvement is achieved by the combining and development of instrumentations and data evaluation tools from two research fields: the fields of near infrared spectroscopy and biomedical optics. LÄS MER