Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Abstract. The high current SRF electron accelerator facility ELBE started user operation at the Bremsstrahlung facility in 2003, followed straight-line by channelling X-rays and the infrared FEL laboratories. Since then, automated beam stabilization in terms of energy, intensity and also trajectory became a clear necessity for a number of experiments carried out. This contribution describes observed instabilities of the electron beam and the infrared beam at FELBE and alludes to their certain or possible sources. For slow (mHz) beam energy drift compensation, a dispersion based feedback loop was developed and implemented, using strip line beam position monitors and the accelerating RF gradient. Further, the IR beam intensity is measured by a newly developed scatter wire detector system and stabilized via the electron beam current up to the few Hz range. Control theory aspects used to design both solutions are shown, also their implementation into the existing ELBE control landscape and performance characteristics.