Multiphoton ionization and stabilization of helium in superintense xuv fields

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.033414· OSTI ID:21541320

Soerngaard, S A; Askeland, S; Nepstad, R; Foerre, M ^[1]

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1. Department of Physics and Technology, University of Bergen, N-5007 Bergen (Norway)

Multiphoton ionization of helium is investigated in the superintense field regime, with particular emphasis on the role of the electron-electron interaction in the ionization and stabilization dynamics. To accomplish this, we solve ab initio the time-dependent Schroedinger equation with the full electron-electron interaction included. By comparing the ionization yields obtained from the full calculations with the corresponding results of an independent-electron model, we come to the somewhat counterintuitive conclusion that the single-particle picture breaks down at superstrong field strengths. We explain this finding from the perspective of the so-called Kramers-Henneberger frame, the reference frame of a free (classical) electron moving in the field. The breakdown is tied to the fact that shake-up and shake-off processes cannot be properly accounted for in commonly used independent-electron models. In addition, we see evidence of a change from the multiphoton to the shake-off ionization regime in the energy distributions of the electrons. From the angular distribution, it is apparent that the correlation is an important factor even in this regime.

• OSTI ID: 21541320
• Journal Information: Physical Review. A, Vol. 83, Issue 3; Other Information: DOI: 10.1103/PhysRevA.83.033414; (c) 2011 American Institute of Physics; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
ELECTRON-ELECTRON INTERACTIONS
ENERGY SPECTRA
EXTREME ULTRAVIOLET RADIATION
HELIUM
MULTI-PHOTON PROCESSES
PARTICLES
PHOTOIONIZATION
SCHROEDINGER EQUATION
STABILIZATION
TIME DEPENDENCE
DIFFERENTIAL EQUATIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUATIONS
FLUIDS
GASES
INTERACTIONS
IONIZATION
LEPTON-LEPTON INTERACTIONS
NONMETALS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE INTERACTIONS
RADIATIONS
RARE GASES
SPECTRA
ULTRAVIOLET RADIATION
WAVE EQUATIONS