New Approach to Shielding Calculations for Very High Energy Accelerators

A new Monte Carlo program, CASIM, has been written specifically to solve high energy hadron shielding problems. The program starts from inclusive distributions of nucleons and pions from nuclear interactions and generates averages (over many incident particles) of particle fluxes and energy deposition throughout the shield. Within this limitation the program has several advantages over other shielding calculations: a) quite complicated source terms (e.g., Hagedorn's thermodynamical model) can easily be used, b) weighting techniques permit following cascades over large distances as well as examining of selected geometries, heterogeneous media, etc., c) short coding and d) short execution times. Results of CASIM are presented for protons incident on realistic geometries as well as an intercomparison of predictions for a solid beamstop using two different production models.