Emission of thermally activated electrons from rare gas clusters irradiated with intense VUV light pulses from a free electron laser.
The ionization dynamics of Ar and Xe clusters irradiated with intense vacuum ultraviolet light from a free-electron laser is investigated using photoelectron spectroscopy. Clusters comprising between 70 and 900 atoms were irradiated with femtosecond pulses at 95 nm wavelength (approximately 13 eV photon energy) and a peak intensity of approximately 4 x 10(12) W/cm2. A broad thermal distribution of emitted electrons from clusters with a maximum kinetic energy up to 30-40 eV is observed. The observation of relatively low-energy photoelectrons is in good agreement with calculations using a time-dependent Thomas-Fermi model and gives experimental evidence of an outer ionization process of the clusters, due to delayed thermoelectronic emission.
Laarmann
T
T
Max-Born-Institute, Max-Born Strasse 2a, D-12489 Berlin, Germany. laarmann@mbi-berlin.de
Rusek
M
M
Wabnitz
H
H
Schulz
J
J
de Castro
A R B
AR
Gürtler
P
P
Laasch
W
W
Möller
T
T