The biological shield of a high-intensity spallation source: a Monte Carlo design study

The design of high-intensity spallation sources requires best possible estimates for the biological shield. We discuss the layout of the target station shield using Monte Carlo simulation techniques. In order to achieve reasonable computing times together with acceptable accuracy biasing techniques are to be employed and it is the main purpose of this study to develop a calculational strategy for a 3D Monte Carlo simulation in effective shielding design. Two transport codes, MCNPX and FLUKA, are then applied to the same model spallation source (the European Spallation Source) and the results are compared.