ABSTRACT A deep-penetration shielding experiment was performed at the CERN High-energy AcceleRator Mixed-field (CHARM) facility. The protons (24 GeV/c) were injected into a 50-cm-thick copper target and the released neutrons were transmitted through a bulk concrete shield located vertically upward from the target, where they were measured with bismuth and aluminum activation detectors placed at various penetration distances in the shield. From the radionuclide production rate in the activation detectors, the attenuation profiles through the concrete shield were obtained for the reactions of 209Bi(n,xn)210-x Bi(x = 4–9) and 27Al(n,α)24Na. The attenuation length of the high-energy neutrons through ordinary concrete was estimated as 120 g/cm2, in good agreement with Monte Carlo simulations using simple slabs as a universal geometry implemented in Particle and Heavy Ion Transport System (PHITS) code. Proton energy dependence of attenuation length was also investigated with simulations by PHITS code and comparisons with the published data were discussed.

中文翻译：

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高能中子穿过厚混凝土屏蔽层的衰减长度由 CHARM 的激活探测器测量

摘要 在欧洲核子研究中心高能加速器混合场 (CHARM) 设施中进行了一次深穿透屏蔽实验。质子 (24 GeV/c) 被注入 50 厘米厚的铜靶中，释放的中子通过位于靶垂直向上的大块混凝土屏蔽传输，在那里用放置在不同位置的铋和铝激活探测器进行测量。护盾中的穿透距离。从激活探测器中的放射性核素产生率，通过混凝土屏蔽获得 209Bi(n,xn)210-x Bi(x = 4-9) 和 27Al(n,α)24Na 反应的衰减曲线。高能中子穿过普通混凝土的衰减长度估计为 120 g/cm2，与使用简单板作为在粒子和重离子传输系统 (PHITS) 代码中实现的通用几何形状的蒙特卡罗模拟非常一致。还通过 PHITS 代码的模拟研究了衰减长度的质子能量依赖性，并讨论了与已发布数据的比较。