High-accuracy determination of the U 238 / U 235 fission cross section ratio up to ˜ 1 GeV at n_TOF at CERN
High-accuracy determination of the U 238 / U 235 fission cross section ratio up to ˜ 1 GeV at n_TOF at CERN
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在 CERN 的 n_TOF 处高精度测定高达 Ë 1 GeV 的 U 238 / U 235 裂变截面比
DOI：
10.1103/physrevc.91.024602
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发表时间：
2015
影响因子：
3.1
通讯作者：
Paradela C
中科院分区：
文献类型：
--
作者：
Paradela C
用两种不同的探测系统，在不同的几何构型下，在n_TOF高达101 GeV的条件下，测定了U与U的裂变截面比。总共收集并比较了四个数据集。在3- 4%的相对系统不确定度范围内，它们都是一致的。在n_TOF收集的数据已被适当地组合，以产生一个独特的裂变截面比作为中子能量的函数。结果证实了目前的评估高达200兆电子伏。也观察到良好的协议与理论计算的基础上INCL++/双子座++组合的最高测量能量。n_TOF结果可能有助于解决迄今为止超过20 MeV的两个最重要的实验数据集之间长期存在的差异，同时首次将中子能量范围扩展到100 GeV。
The ²³⁸U to ²³⁵U fission cross section ratio has been determined at n_TOF up to ≈1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets has been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3-4%. The data collected at n_TOF have been suitably combined to yield a unique fission cross section ratio as a function of neutron energy. The result confirms current evaluations up to 200 MeV. Good agreement is also observed with theoretical calculations based on the INCL++/Gemini++ combination up to the highest measured energy. The n_TOF results may help solve a long-standing discrepancy between the two most important experimental datasets available so far above 20 MeV, while extending the neutron energy range for the first time up to ≈1 GeV.