Radiation protection at the SwissFEL free electron laser facility: Beam stopping devices - Paper 53
The new large-scale facility SwissFEL (Swiss Free Electron Laser) is currently under construction at the Paul Scherrer Institute. The facility is situated underground in the ground floor of a two-floor building, partly integrated in a recreation area. This results into new challenges for radiation protection related tasks, in particular for the design of beam-stopping devices. The design of each beam-stopping device has to ensure that the dose rate during operation outside of the accelerator vault is in compliance with the legal limits defined by the Swiss radiation protection ordinance. In this work, the final design of the dumps is presented with the description of the underlying operational and legal constraints. Reuse of activated material as concrete, lead and steel is included in the main design criteria. As a result, four beam stopping devices consist for more than 90 % of material already available at PSI. In addition, routine operation and maintenance scenarios are discussed from a radiation protection point of view. (authors)