Speaker
Description
To estimate attenuation of accelerator-produced neutrons in labyrinths and penetrations, we use a semi-analytical technique developed at Fermilab, as well as Monte Carlo radiation transport codes MARS, PHITS, and MCNP. The semi-analytical formalism suggests calculating the neutron attenuation factors for the labyrinth legs based merely on the source term at the entrance of the labyrinth; the source term could be either calculated using a Monte Carlo code, or simply estimated from the beam parameters. On the other hand, Monte Carlo codes, with their realistic underlying physics, calculate the radiation environment inside and outside of the labyrinths in great detail. The Monte Carlo results are more reliable, but they are usually computationally expensive. Knowing the relation between the semi-analytical and Monte Carlo results, one can use a more appropriate technique in time-sensitive situations.