In this study, compounds; which are highly absorbent for neutrons due to their high absorption cross-section, are used in different volume proportions within cubic geometry for concrete as the primary shielding substrate. For this purpose, these compounds were investigated using Monte Carlo simulation method using the MCNP code. For achieving different volume percentages, the radius of the absorbent balls must vary from 200 µm(1%) to 750 µm(52%). The designed sample was exposure to an Am—Be neutron source with 5 Ci intensity. 37.5% of total activity of this source is Gamma emission. The goal of designing the geometry in this form is increasing the probability of interactions of fast and energetic neutrons which are moving along diffusion path inside the shield to decrease the speed and energy of these neutrons by inelastic scattering. The compounds have been investigated CdO, B₄C, and BN; which are filled in serpentine concrete. According to the simulation results, based on the efficiency of various compounds and smooth production of these compounds and also the necessary costs for their production and acceptable descending process of equivalent dose, boron carbide and boron nitride compound exhibited satisfactory performance in reducing equivalent doses. so using these compounds as absorbent balls seems to be a reasonable choice.

中文翻译：

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B 4 C，CdO和BN微粒填充的混凝土中子屏蔽性能的研究

在这项研究中，化合物；由于其吸收截面高，它们对中子具有高吸收性，它们在立方几何形状内以不同的体积比例用于混凝土作为主要的屏蔽基材。为此，使用蒙特卡罗模拟方法使用MCNP代码研究了这些化合物。为了实现不同的体积百分比，吸收球的半径必须改变从200 μ M（1％），以750 μm（52％）。设计的样品暴露于强度为5 Ci的Am-Be中子源。此源的总活动量的37.5％是伽马发射。设计这种形式的几何形状的目的是增加快速中子和高能中子相互作用的可能性，这些中子沿着屏蔽内部的扩散路径移动，以通过非弹性散射降低这些中子的速度和能量。该化合物已经过研究CdO，B ₄C和BN；用蛇形混凝土填充。根据模拟结果，基于各种化合物的效率和这些化合物的平稳生产，以及其生产所需的成本以及可接受的当量剂量下降工艺，碳化硼和氮化硼化合物在降低当量剂量方面表现出令人满意的性能。因此，将这些化合物用作吸收球似乎是一个合理的选择。