Soft x-ray free electron laser microfocus for exploring matter under extreme conditions.
We have focused a beam (BL3) of FLASH (Free-electron LASer in Hamburg: lambda = 13.5 nm, pulse length 15 fs, pulse energy 10-40 microJ, 5 Hz) using a fine polished off-axis parabola having a focal length of 270 mm and coated with a Mo/Si multilayer with an initial reflectivity of 67% at 13.5 nm. The OAP was mounted and aligned with a picomotor controlled six-axis gimbal. Beam imprints on poly(methyl methacrylate) - PMMA were used to measure focus and the focused beam was used to create isochoric heating of various slab targets. Results show the focal spot has a diameter of < or =1 microm. Observations were correlated with simulations of best focus to provide further relevant information.
Nelson
A J
AJ
LawrenceLivermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA. nelson63@llnl.gov
Toleikis
S
S
Chapman
H
H
Bajt
S
S
Krzywinski
J
J
Chalupsky
J
J
Juha
L
L
Cihelka
J
J
Hajkova
V
V
Vysin
L
L
Burian
T
T
Kozlova
M
M
Fäustlin
R R
RR
Nagler
B
B
Vinko
S M
SM
Whitcher
T
T
Dzelzainis
T
T
Renner
O
O
Saksl
K
K
Khorsand
A R
AR
Heimann
P A
PA
Sobierajski
R
R
Klinger
D
D
Jurek
M
M
Pelka
J
J
Iwan
B
B
Andreasson
J
J
Timneanu
N
N
Fajardo
M
M
Wark
J S
JS
Riley
D
D
Tschentscher
T
T
Hajdu
J
J
Lee
R W
RW
D017076:Computer-Aided Design; D004583:Electrons; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D007909:Lenses; D008422:Materials Testing / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014961:X-Ray Diffraction / Q000295:instrumentation* / Q000379:methods*