At the Joint Institute for Nuclear Research (JINR) we are involved in the Accelerator-Driven-System (ADS) research. We perform experiments with assemblies composed of a spallation target and a subcritical blanket irradiated with high-energy proton or deuteron beams that generate high-energy neutron fields by spallation and fission reactions. In this paper, three uranium assemblies are presented: Energy plus Transmutation (E+T), QUINTA and BURAN. We discuss the results of the E+T and QUINTA irradiations by 1.6 GeV deuterons and 660 MeV protons, respectively. We have focused on the regions close to the primary beam passage through the targets. The field has been measured using activation detectors of ²⁰⁹Bi, ⁵⁹Co, and ^natPb. Monte Carlo simulations using MCNPX 2.7.0 have been performed and compared to the experimental results. We discovered that the field intensity near the primary beam is very dependent on the precision of the accelerator beam settings. Therefore, a Monte Carlo-based study of the influence of the uncertainty of primary proton beam parameters on experimental result accuracy of the QUINTA assembly has been carried out. The usage of MCNPX 2.7.0 in the future BURAN irradiations has been assessed.

中文翻译：

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监测散落靶中主质子和氘核束附近的混合中子-质子场

在联合核研究所（JINR），我们参与了加速器驱动系统（ADS）研究。我们对由散裂靶和亚临界覆盖层组成的组件进行实验，该覆盖层由高能质子或氘核束辐照，并通过散裂和裂变反应产生高能中子场。本文介绍了三种铀组件：能量加Trans变（E + T），QUINTA和BURAN。我们分别讨论了1.6 GeV氘核和660 MeV质子对E + T和QUINTA的辐照结果。我们将重点放在靠近穿过目标的主光束通道的区域上。该场已使用²⁰⁹ Bi，⁵⁹ Co和^nat的激活检测器进行了测量铅 已经进行了使用MCNPX 2.7.0的蒙特卡罗模拟，并将其与实验结果进行了比较。我们发现，主光束附近的场强非常取决于加速器光束设置的精度。因此，已经进行了基于蒙特卡洛的对质子束主参数参数不确定性对QUINTA组件实验结果精度的影响的研究。已经评估了MCNPX 2.7.0在将来的BURAN照射中的使用。