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Abstract

In this thesis Coulomb-explosions of allene molecules (C₃H₄) induced by intense infrared (IR) and extreme ultraviolet (XUV) laser pulses are studied. Over the full solid angle charged particles are detected with a reaction microscope. A software for simulation of molecular fragmentation processes has been developed to facilitate the interpretation of multi-ion coincidence spectra. Multi-photon double-ionization of allene by intense IR pulses with pulse lengths below 10 fs reveals six double-ion fragmentation channels of which four show indications of an isomerization process. Triple-ion fragmentations have not been observed. Measured kinetic energy releases of all Coulomb-explosion channels are independent of IR pulse intensity and of IR pulse length. They also do not differ, if XUV pulses are used. Branching ratios of stable and unstable dications feature a dependence on the intensity of IR pulses. The half-life of long-lived metastable allene dications is estimated from time-of-flight spectra. Pump–probe measurements with XUV and IR pulses indicate dynamics of allene dications on time scales of 50 fs.