Measurement of 2l-nl' x-ray transitions from approximately 1 microm Kr clusters irradiated by high-intensity femtosecond laser pulses.
X-ray line emission from 2l-nl' transitions in Ne-like Kr and nearby ions has been observed from approximately 1 microm Kr clusters irradiated by fs-scale laser pulses at the JAERI facility in Kyoto, Japan. The incident laser intensity reached 10(19) W/cm2, with pulse energies from 50 to 300 mJ and pulse durations from 30 to 500 fs. The dependence of the x-ray spectral features and intensity on the incident laser intensity is rather weak, indicating that the 1-2 ps cluster lifetimes limit the number of ions beyond Ne-like Kr that can be produced by collisional ionization. Lines from F- to Al-like Kr emitted from the cluster plasmas have been identified using data from the relativistic multiconfiguration flexible atomic code. A collisional-radiative model based on these data has been constructed and used to determine that the cluster plasma has electron densities near 10(22) cm(-3), temperatures of a few hundred eV, and hot electron fractions of a few percent.
Hansen
S B
SB
Lawrence Livermore National Laboratory, P.O. Box 808, L-473, Livermore, California 94550, USA.
Fournier
K B
KB
Faenov
A Ya
AY
Magunov
A I
AI
Pikuz
T A
TA
Skobelev
I Yu
IY
Fukuda
Y
Y
Akahane
Y
Y
Aoyama
M
M
Inoue
N
N
Ueda
H
H
Yamakawa
K
K