Sökning: "Attosecond"
Visar resultat 1 - 5 av 51 avhandlingar innehållade ordet Attosecond.
1. Attosecond Electron Wave Packet Interferences
Sammanfattning : Attosecond pulses offer a new route to produce temporally localized electron wave packets (EWPs) that can easily be tailored by altering the properties of the attosecond pulses. In this thesis we will present different experiments, supported by theory, where attosecond EWPs are created in presence of a strong infrared (IR) field. LÄS MER
2. Attosecond Wave Packet Metrology
Sammanfattning : Attosecond pulses allow the study of electrons on their natural timescale. They are created from the interaction of atoms with ultrashort, intense laser pulses whose electric field approaches the strength of inner-atomic electric fields. This thesis presents experiments around the generation, characterization and application of attosecond pulses. LÄS MER
3. Sources and Diagnostics for Attosecond Science
Sammanfattning : Ultrafast science refers to physical events that happen on the femtosecond (1 fs=10^-15 s) and attosecond (1 as=10^-18 s) timescales. Generation of attosecond pulses is usually achieved by interacting high-intensity femtosecond pulses with matter (typically gases), in a process called high-order harmonic generation (HHG). LÄS MER
4. Time-Frequency Analysis in Attosecond Spectroscopy
Sammanfattning : This thesis deals with ultrafast dynamics of electronic processes in rare gas atoms. The processes we explore include photoemission, where we time the emission of electrons moving away from the atomic core following ionization by a photon; and auto-ionization, where the atom spontaneously releases an electron wave-packet following photo-excitation. LÄS MER
5. Computing attosecond delays in atomic photoionisation : A non-iterative method for many-electron correlation within the Random Phase Approximation with Exchange
Sammanfattning : När en atom absorberar fotoner, i växelverkan med tillräckligt högenergetisktljus, så kan en (eller flera) av atomens elektroner ”sparkas ut”. Det resulterar i en positivt laddad jon och en (eller flera) så kallade fotoelektroner. Den här processen är känd som den fotoelektriska effekten, men kallas också för fotojonisering. LÄS MER
