Monte Carlo optimization simulation of neutron shielding performance of iron/polyethylene combined structure

Abstract

This study aims to get the optimization neutron shielding design of iron/polyethylene combined shield structure. The neutron transmission coefficient with various energies for different thickness of iron and polyethylene combined shield structure were calculated by using Monte Carlo method. The simulation results show that the optimization effect of iron/polyethylene combined shield is not obvious when the neutron energy is low or the shield is thin, there is an optimal thickness ratio of iron to polyethylene adopted to get the best neutron shielding performance when the energy of neutron source is above 2 MeV and the total thickness of combined shielding structure is more than 20 cm. The optimal thickness ratio of iron to polyethylene increases with the increasing energy of neutron source; with the increasing of neutron source energy ranging from 4 MeV to 14 MeV, the optimal thickness ratio of iron to polyethylene trends from 0.11 to nearly 1.6.

Combined Method of Bulk Material Shielding Evaluation for 200 Mev High Energy Neutron Source Using Phits Modelling and Partial Density

“…Compared to a prior work in which Zuo Y et al [24] did an optimization simulation on neutron shielding from a 14 MeV neutron source, iron demonstrated greater shielding effectiveness than polyethylene materials. Jin-Long Wang et al [45] also observed the iron configuration on the shielding design for secondary neutrons at the synchrotron-based proton therapy (PT) facility with the injection proton energy of 3.5 MeV has a smaller thickness than the concrete.…”

“…Consequently, this research verifies previous findings that iron has excellent shielding capabilities for fast neutrons, not only for 14 meV neutron energy distribution and high proton energy distribution but also for 200 MeV neutron energy. The absorption cross-section significantly affects the neutron energy below 1 eV; therefore, polyethylene material is the best option for low neutron shielding material [12,17,24]. However, there are better choices than polyethylene for fast neutrons.…”