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Abstract

Experimental developments in the field of petawatt lasers promise to provide in the near future strong zeptosecond multi-MeV photon pulses. The interaction of such pulses with nuclei would provide access to regimes so far unexplored of high nuclear excitation energy and low angular momentum. In this thesis we investigate theoretically for the first time the sudden regime of laser-nucleus interaction, in which multiple photon absorption occurs faster than the nucleus has time to equilibrate. We construct a master equation that determines the temporal evolution of the nuclear state starting from the underlying processes: dipole absorption, stimulated dipole emission, equilibration and neutron evaporation. Equilibration is taken into account by considering the coupling of states with different particle-hole numbers at constant energy. We use state-of-the-art matrix exponential solvers based on the Chebyshov rational approximation method to solve numerically the master equation. The results show the interplay between photon absorption and nuclear equilibration and its effects on neutron emission. Our quantitative estimates predict the excitation path and range of nuclei reached by neutron decay towards the proton-rich region of the nuclide table and provide relevant information for the layout of future experiments.