Electron bunch timing with femtosecond precision in a superconducting free-electron laser.
High-gain free-electron lasers (FELs) are capable of generating femtosecond x-ray pulses with peak brilliances many orders of magnitude higher than at other existing x-ray sources. In order to fully exploit the opportunities offered by these femtosecond light pulses in time-resolved experiments, an unprecedented synchronization accuracy is required. In this Letter, we distributed the pulse train of a mode-locked fiber laser with femtosecond stability to different locations in the linear accelerator of the soft x-ray FEL FLASH. A novel electro-optic detection scheme was applied to measure the electron bunch arrival time with an as yet unrivaled precision of 6 fs (rms). With two beam-based feedback systems we succeeded in stabilizing both the arrival time and the electron bunch compression process within two magnetic chicanes, yielding a significant reduction of the FEL pulse energy jitter.
Löhl
F
F
Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany. florian.loehl@cornell.edu
Arsov
V
V
Felber
M
M
Hacker
K
K
Jalmuzna
W
W
Lorbeer
B
B
Ludwig
F
F
Matthiesen
K-H
KH
Schlarb
H
H
Schmidt
B
B
Schmüser
P
P
Schulz
S
S
Szewinski
J
J
Winter
A
A
Zemella
J
J