Abstracts Brochure - CERN

TUPCH028
TUPCH029
TUPCH030
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
Layout of the Optical Synchronization System for the VUV-FEL
A. Winter, P. Schmüser, A. Winter (Uni HH) F.O. Ilday (Bilkent
University) F.X. Kaertner (MIT) F. Loehl, F. Ludwig, H. Schlarb, B.
Schmidt (DESY)
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The present RF synchronization system of
the VUV-FEL can typically stabilize the arrival
time of the electron bunches at the undulator
to about 200 fs on a timescale of
minutes and to several picoseconds on a
timescale of hours. To improve the machine stability and to ensure optimal performance for the VUV-FEL user
facility, a new ultra-precise timing system is mandatory. The optical synchronization system under construction will
satisfy three goals: Firstly, it provides a local oscillator frequency with the same stability as the existing low-level
RF regulation, secondly, it can synchronize the experimental lasers of the FEL users with a precision in the order of
30 fs, thirdly, it provides an ultra-stable reference for beam arrival time measurements and enables a feedback on
the electron beam to compensate residual drifts and timing jitter. The optical synchronization system is based on
an optical pulse train from a mode-locked laser with a highly stabilized repetition rate. This paper describes the
proposed layout of the optical synchronization system, the integration into the machine layout and the diagnostic
experiments to monitor the performance of the system.
High-precision Laser Master Oscillators for Optical Timing Distribution Systems
A. Winter, P. Schmüser, A. Winter (Uni HH) J. Chen, F.X. Kaertner
(MIT) F.O. Ilday (Bilkent University) F. Ludwig, H. Schlarb (DESY)
X-ray pulses with a pulse duration in the 10 fs
regime or even less are needed for numerous
experiments planned at next generation free
electron lasers. A synchronization of probe
laser pulses to the x-ray pulses with a stability on the order of the pulse width is highly desirable for these experiments.
This requirement can be fulfilled by distributing an ultra-stable timing signal to various subsystems of the machine
and to the experimental area to provide synchronization at the fs level over distances of several kilometers. Modelocked
fiber lasers serve as laser master oscillators (LMO), generating the frequencies required in the machine. The
pulse train is distributed through length-stabilized fiber links. This paper focuses on the LMO, devoting special
attention to the phase noise properties of the frequencies to be generated, its reliability to operate in an accelerator
environment, and the residual timing jitter and drifts of the RF feedback for the fiber links. A prototype experimental
system has been constructed and tested in an accelerator environment and its performance characteristics will be
evaluated.
A Beam Diagnostics System for the Heidelberg Cryogenic Storage Ring CSR
At the MPI-K Heidelberg a cryogenic storage
T. Sieber, M. Grieser, A. Wolf, R. von Hahn (MPI-K)
ring (CSR) for atomic- and molecular physics
experiments is under development. The CSR
shall prove the possibility of ring operation at very low temperatures (