Classical explanation for electrons above energy 2 Up in strong-field double ionization at 390 nm

Physical Review A - Atomic, Molecular, and Optical Physics

Volumn 76, Issue 5, 2007, Pages

  Haan, S L ^a   Smith, Z S ^a  

^a CALVIN COLLEGE   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

HELIUM; IMPACT IONIZATION; TIME DELAY; WAVELENGTH;

DOUBLE IONIZATION; ELECTRON ENERGY; LASER FORCES;

ELECTRONS;

EID: 36248990105     PISSN: 10502947     EISSN: 10941622     Source Type: Journal    
DOI: 10.1103/PhysRevA.76.053412     Document Type: Article

References (24)

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20. The maximum return energy can be estimated as 3.17 Up =1.83 au. For nuclear shielding parameter a=0.825 (described in the text), our well depth after single ionization is -2.4 au, below the energy -2.0 au of the helium ion. For the electron-electron interaction we use shielding parameter 0.05 au.
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23. When the shielding parameter is reduced, there is a small starting region around z=-5.6 au that leads to final electron energy 3.5 Up. If one allows initial perpendicular velocity vx =0.1, then there is a larger starting region near z=-5.6 au and x=-1.65 for which the electron scatters off the nucleus into the z direction, and finishes with energy 3.4 Up.
24. If we examine high-energy trajectories 0.10c before final ionization, we find that as the Coulomb shielding is reduced the percentage of high-energy trajectories in which the high-energy electron is bound and the low-energy free drops from 56 to 15%, and the percentage in which the high-energy electron is free and the low-energy bound increases from 23 to 68%. Also, the number of trajectories in which both electrons achieve high energy increases from 2 to 10%. The remaining 7% of the high-energy trajectories are doubly excited at the chosen time.