Tracking studies of top-up injection for a safe operation of the ESRF-EBS

Abstract Since 25th August 2020 the new European Synchrotron Radiation Facility Extremely Brilliant Source (ESRF EBS) storage ring (Biasci et al., 2014 and Admans et al., 2014)  [1] , [2] has been providing beam to users in top-up mode with front-end (FE) shutters open. The obvious need to extract X-rays from the electron vacuum chamber generates a potential in-vacuum gate available to 6 GeV electrons for reaching the beam-line hutches. This event represents a major radio-protection issue (Berkvens, 2020)  [3] . We must thus assure that no electron will ever reach the beam-line hutches in the presence of stored beam with FE open. To this end, we performed a complete set of simulations to assess the safety of top-up injection including all possible scenarios.