Cosmic-ray neutrons (CRNs) account for about half of the radiation dose recieved by airline crews and passengers at aviation altitudes. CRNs also comprise important background radiation near the ground, which should be considered in neutron counts for the purpose of nuclear safeguarding and homeland security. In this study, simulations were conducted with the Geant4 toolkit to describe the air shower of cosmic rays. The latest experimental driving models for the atmosphere, geomagnetic field, and primary galactic cosmic rays were applied in these simulations. The simulation was validated by comparing the results with those measured on the NASA ER-2 aircraft. the CRN fluxes and spectra were calculated at altitudes ranging from one to tens of kilometers. We determined the characteristics of the CRN spectra and analyzed their dependency on the altitude. To consider their impact on the local environment, the CRNs near the ground were modeled with a specific equivalent approach, which allowed the simulations to be conducted with limited computer processing power. The parameters for the incident primary CRNs near the ground were calculated by simulating the cosmic ray air shower. The modeling dimensions were considered for the air and ground, and an appropriate approximation solution was obtained. The model near the ground was used to investigate the dependences of the CRN flux and spectrum on the soil moisture.

宇宙射线中子 (CRN) 约占航空公司机组人员和乘客在航空高度接收的辐射剂量的一半。CRN 还包括重要的近地背景辐射，出于核安全保障和国土安全的目的，应在中子计数中考虑这些辐射。在这项研究中，使用 Geant4 工具包进行了模拟，以描述宇宙射线的空气簇射。在这些模拟中应用了最新的大气、地磁场和初级银河宇宙线实验驱动模型。通过将结果与在 NASA ER-2 飞机上测量的结果进行比较来验证模拟。CRN 通量和光谱是在 1 到数十公里的高度计算的。我们确定了 CRN 光谱的特征并分析了它们对高度的依赖性。为了考虑它们对当地环境的影响，靠近地面的 CRN 使用特定的等效方法进行建模，这允许在有限的计算机处理能力下进行模拟。近地入射初级CRN的参数是通过模拟宇宙射线空气簇射来计算的。考虑了空气和地面的建模尺寸，并获得了适当的近似解。靠近地面的模型用于研究 CRN 通量和光谱对土壤水分的依赖性。这允许在有限的计算机处理能力下进行模拟。近地入射初级CRN的参数是通过模拟宇宙射线空气簇射来计算的。考虑了空气和地面的建模尺寸，并获得了适当的近似解。靠近地面的模型用于研究 CRN 通量和光谱对土壤水分的依赖性。这允许在有限的计算机处理能力下进行模拟。近地入射初级CRN的参数是通过模拟宇宙射线空气簇射来计算的。考虑了空气和地面的建模尺寸，并获得了适当的近似解。靠近地面的模型用于研究 CRN 通量和光谱对土壤水分的依赖性。