Few-photon multiple ionization of ne and ar by strong free-electron-laser pulses.
Few-photon multiple ionization of Ne and Ar atoms by strong vacuum ultraviolet laser pulses from the free-electron laser at Hamburg was investigated differentially with the Heidelberg reaction microscope. The light-intensity dependence of Ne2+ production reveals the dominance of nonsequential two-photon double ionization at intensities of I<6x10(12) W/cm2 and significant contributions of three-photon ionization as I increases. Ne2+ recoil-ion-momentum distributions suggest that two electrons absorbing "instantaneously" two photons are ejected most likely into opposite hemispheres with similar energies.
Moshammer
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R
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
Jiang
Y H
YH
Foucar
L
L
Rudenko
A
A
Ergler
Th
T
Schröter
C D
CD
Lüdemann
S
S
Zrost
K
K
Fischer
D
D
Titze
J
J
Jahnke
T
T
Schöffler
M
M
Weber
T
T
Dörner
R
R
Zouros
T J M
TJ
Dorn
A
A
Ferger
T
T
Kühnel
K U
KU
Düsterer
S
S
Treusch
R
R
Radcliffe
P
P
Plönjes
E
E
Ullrich
J
J