Few-photon multiple ionization of N2 by extreme ultraviolet free-electron laser radiation.
Few-photon multiple ionization of N2 was studied differentially in a reaction microscope using 44 eV, approximately 25 fs, intense ( approximately 10(13) W/cm(2)) photon pulses from FLASH. Sequential ionization is observed to dominate. For various intermediate charge states N(2)(n+0 we find a considerable excess of photons absorbed compared to the minimum number that would energetically be required. Photoionization of aligned N(2)(n+) ions, produced by photon absorption in sequential steps, is explored and few-photon absorption pathways are traced by inspecting kinetic energy releases and fragment-ion angular distributions.
Jiang
Y H
YH
Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany.
Rudenko
A
A
Kurka
M
M
Kühnel
K U
KU
Ergler
Th
T
Foucar
L
L
Schöffler
M
M
Schössler
S
S
Havermeier
T
T
Smolarski
M
M
Cole
K
K
Dörner
R
R
Düsterer
S
S
Treusch
R
R
Gensch
M
M
Schröter
C D
CD
Moshammer
R
R
Ullrich
J
J