Monte Carlo studies for the radiation shielding of LCLS-II

*Intensive Monte Carlo simulations performed with state-of-the-art computation codes are applied to the radiation shielding design of LCLS-II, which will be the extension of Linac Coherent Light Source (LCLS) at SLAC and will use the middle one-third of SLAC two-mile Linac. This paper describes the Monte Carlo studies of the first and last system where electron beams are involved, namely the LCLS-II Injector and the X-ray Transport and Diagnostics System (XTOD).