Radiation Shielding And Radiation Protection Issues At The European Synchrotron Radiation Facility P Berkvens*, European Synchrotron Radiation Facility

Abstract: The paper describes specific radiation shielding and radiation protection issues at the ESRF, the 6 GeV third generation light source in Grenoble, France. A very strict radiation protection policy has been adopted at the ESRF since many years, whereby all persons working at the facility, including users and contractors must be considered as non-exposed workers, using a derived dose constraint of 2 mSv (0.2 mrem) integrated over 4 hours. Special attention will be given to electron loss patterns in the storage ring and corresponding dose distributions outside the shield walls and to gas-bremsstrahlung issues and photo-neutrons around beamline hutches. These aspects will be discussed in the framework of the upgrade of the facility, including the creation of longer insertion device straight sections (including the provision for canted undulators) and a possible increase of the stored electron current from 200 mA to 300 mA. Results from calculations and results from measurements, both outside the storage ring and around beamline hutches, will be presented. Since several years the ESRF is operating in a non-continuous topping-up mode, with the front end shutters remaining open during injection. The paper will include an overview of radiation measurements outside the beamlines’ optics hutches, in relation to this mode of operation.