Open Access Version

Abstract:
In the advent of diffraction-limited storage rings (DLSR) [1], long-term plans for a possible successor of the BESSY II storage ring are under investigation. Such a facility would have a significantly reduced beam lifetime compared to a standard third-generation light source, placing stringent requirements on radiation protection, especially on controlling the annual number of injected electrons per year and on shielding design. A complex facility like this cannot be simulated in total and in necessary detail in a reasonable time frame. Therefore, semi-empirical shielding formulas [2-6] can be an essential tool for designing an overall shielding concept. Existing formulas had been mostly devised for and fitted to different parameter regimes than those common to next-generation light sources. In this paper, we present recent FLUKA [7, 8] simulations tailored to adapt the existing formulas to the specific needs of a possible BESSY II successor. For example, source terms for niobium, and the giant resonance neutron yield as function of target length for different materials are derived.