Speakers
Dr
Stefan Simrock
(DESY)Dr
Valeri Ayvazyan
(DESY)
Description
In the RF system for the Vacuum Ultraviolet Free Electron Laser (VUV-FEL) Linac each
klystron supplies RF power to up to 32 cavities. The superconducting cavities are
operated in pulsed mode and high accelerating gradients close to the performance
limit. The RF control of the cavity fields to the level of 1e-4 for amplitude and
0.1 degree for phase however presents a significant technical challenge due to the
narrow bandwidth of the cavities which results in high sensitivity to perturbations
of the resonance frequency by mechanical vibrations (microphonics) and Lorenz force
detuning. The VUV-FEL Linac RF control system employs a completely digital feedback
system to provide flexibility in the control algorithms, precise calibration of the
accelerating field vector-sum, and extensive diagnostics and exception handling
capabilities. The RF control algorithm is implemented in DSP firmware and DOOCS
(Distributed Object Oriented Control System) servers. The RF control system design
objectives are discussed. Hardware and software design of the DSP based RF control
are presented.
Authors
Dr
Stefan Simrock
(DESY)
Dr
Valeri Ayvazyan
(DESY)
Co-authors
Dr
Alexander Matyushin
(DESY)
Mr
Gevorg Petrosyan
(DESY)
Mr
Guenter Moeller
(DESY)
Mr
Kay Rehlich
(DESY)
Dr
Petr Vetrov
(DESY)
Dr
Stefan Choroba
(DESY)
