Radiation Shielding Materials: Half-value layer determination for separate and simultaneous photonand neutron emissions by a 252Cf source

The present study aimed to determine half-value layers (hvl) ofdifferent materials with neutron, photon, and simultaneous neutron andphoton emissions by a 252cf source. mcnpx code was used for the simulationof the applicator tube (at) 252cf source and the attenuation materials.materials and methods: the 252cf source, a source collimator, a detector, adetector collimator, and hvl material were defined in the present study. hvlwas determined for lead, concrete, water, polyethylene, and polyethylenemixtures with various concentrations of boric acid for separate neutron,separate photon, and simultaneous emissions of neutron and photon by the252cf source. results: hvl values were tabulated for the aforementionedmaterials for separate neutron, separate photon, and for simultaneousneutron and photon emissions by the 252cf source. among the evaluatedmaterials, polyethylene was the most adequate material for neutronshielding. conclusion: the obtained hvl results for different materials couldbe used for shielding design around a 252cf source. according to thecomparison of lead with concrete, lead was a suitable material for shieldingagainst the photons emission. on the other hand, concrete with a lower hvlvalue seemed to be superior for neutron shielding. the combination ofseveral hvl layers of polyethylene and lead could result in proper shieldingagainst neutron and photon. in simultaneous neutron and photon emissions,the emitted neutrons from the source generate secondary photons. the issueled to increase hvl, and could be considered in the protection and shieldingagainst the source.keywords: hvl, attenua