Photoionization of helium by attosecond pulses: extraction of spectra from correlated wave functions
Autor: | Johannes Feist, Emil Persson, Matthias Liertzer, Luca Argenti, Joachim Burgdörfer, Eva Lindroth, Stefan Nagele, Renate Pazourek |
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Přispěvatelé: | UAM. Departamento de Física de la Materia Condensada |
Jazyk: | angličtina |
Rok vydání: | 2012 |
Předmět: |
Physics
education.field_of_study Atomic Physics (physics.atom-ph) Wave packet Double ionization Attosecond Population Física FOS: Physical sciences Photoionization 01 natural sciences Atomic and Molecular Physics and Optics Spectral line 3. Good health 010305 fluids & plasmas Physics - Atomic Physics Photoexcitation Autoionization 0103 physical sciences Physics::Atomic and Molecular Clusters Physics::Atomic Physics Atomic physics 010306 general physics education |
Zdroj: | Biblos-e Archivo. Repositorio Institucional de la UAM instname |
Popis: | We investigate the photoionization spectrum of helium by attosecond XUV pulses both in the spectral region of doubly excited resonances as well as above the double ionization threshold. In order to probe for convergence, we compare three techniques to extract photoelectron spectra from the wavepacket resulting from the integration of the time-dependent Schroedinger equation in a finite-element discrete variable representation basis. These techniques are: projection on products of hydrogenic bound and continuum states, projection onto multi-channel scattering states computed in a B-spline close-coupling basis, and a technique based on exterior complex scaling (ECS) implemented in the same basis used for the time propagation. These methods allow to monitor the population of continuum states in wavepackets created with ultrashort pulses in different regimes. Applications include photo cross sections and anisotropy parameters in the spectral region of doubly excited resonances, time-resolved photoexcitation of autoionizing resonances in an attosecond pump-probe setting, and the energy and angular distribution of correlated wavepackets for two-photon double ionization. 19 pages, 12 figures |
Databáze: | OpenAIRE |
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