In the actual installation and layout process of shielding devices,structural gaps are usually difficult to avoid,and different gaps have significant differences in their impact on the shielding effect of the device.This article is based on the Monte Carlo program Geant4,and investigates the effects of gap in concrete,iron(Fe),and lead(Pb)structures on 60Co and 137Cs sources,respectively calculate the attenuation factor of the γ ray and the half-value layer Δ1/2.Focus on analyzing and studying the shielding performance of different shielding materials under different straight seam widths and Pb shielding performance under different types of structural seam widths;and experimental verification was conducted on the calculation results of Fe plates with different straight seam widths under the same conditions.The results show that,for straight seams,as the thickness of the shielding body increases,the lower half value layer Δ1/2 of the same gap width gradually increases;Among the five types of structural gaps,the oblique seam has the smallest negative impact on the shielding effect of Pb shielding material.For every 1 mm increase in width,the average increase in half value layer Δ1/2 is about 2.03％(60Co)and 2.02％(137Cs),followed by single V seam,and the worst is straight seam.This study mainly evaluates the impact of various gap structures on the protective effect of shielding devices,which has important application value in guiding the structural design and selection of shielding devices.
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