Polyethylene/boron composite materials in X-ray attenuation

Abstract

Currently, lead is used as radiological protection due to its high density in both, personal protection and shielding of equipment.. Iron, concrete or water can also be used to stop X-rays and gamma radiation. Shielding thicknesses are different since these materials have different densities. The used measurement is expressed in values of HVL (hemirreductor thickness in cm). In the case of lead, calculations to stop a photon with an energy of 3000 keV, give a shield of 1.5 cm in thickness. Therefore, a plate of 30x40 cm2 will weigh 20 kg, taking into account its density. LDPE and B composite materials are used as neutron shields: polyethylene, because of its high hydrogen content and boron for its ability to absorb neutrons. For this reason, the objective is to replace lead or other heavy materials by boron PMCs with lower densities for the manufacture of radiological shields. For this purpose, low density polyethylene films and LDPE composite films with 15-30 and 60% wt. of boron were made. Films have been manufactured by hot extrusion and compression. The test that has been carried out is to calculate the shielding effect on the aluminum of these films using X-rays provided by a laboratory equipment used for the characterization of materials. The results have shown a greater shielding for a multilayer system, than a single one with the same thickness.