A New International Evaluation of the Neutron Cross Section Standards
A New International Evaluation of the Neutron Cross Section Standards
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DOI：
10.1080/00223131.2002.10875366
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发表时间：
2002-08
影响因子：
1.2
通讯作者：
A. Carlson
中科院分区：
文献类型：
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作者：
A. Carlson
大多数中子截面的测量都是相对于中子截面标准进行的。对ENDF/B-VI标准的最后一次完整评估发生在近15年前。ENDF/B-VI评价的截面标准为H（n, n）、3He（n, p）、6Li（n, t）、10B（n, α）、10B（n, α）、C（n, n）、Au（n, γ）和235U（n, f）反应。另外一些重要的反应，包括在NEANDC/INDC核标准文件中用作标准截面的238U（n, f）截面，也进行了评估。这些标准在国际上得到接受，以确保所有评价项目都使用同一套标准。自评价完成以来，对该标准进行了重大的实验活动，这将导致对该标准的新评价发生变化。目前正在进行国际努力，以更新以前的工作，包括自评价完成以来所作的标准测量，并改进评价进程。由于高能量标准的需要，部分截面标准的能量区域将扩大到200 MeV左右。标准评估工作已开始对已完成的实验进行调查，以确定数据集内部和数据集之间的不确定性和相关性。与ENDF/B-VI使用的评价程序相比，进一步的工作可能导致改进的评价程序。将讨论这一评价工作的现状。
The measurements of most neutron cross sections are made relative to neutron cross section standards. The last complete evaluation of the standards, which was for ENDF/B-VI, took place almost 15 years ago. The cross section standards produced for the ENDF/B-VI evaluation were for the H(n, n), 3He(n, p), 6Li(n, t), 10B(n, α), 10B(n, α1γ), C(n, n), Au(n, γ) and 235U(n, f) reactions. Some additional important reactions including the 238U(n, f) cross section, which is used as a standard cross section in the NEANDC/INDC Nuclear Standards File, were evaluated. These standards were accepted internationally to ensure that all evaluation projects were using the same set of standards. Significant experimental activity on the standards has occurred since that evaluation was completed which will cause changes in a new evaluation of the standards. International efforts are now underway to update the previous work by including standards measurements made since that evaluation was completed and to improve the evaluation process. Due to the need for high energy standards, the energy region will be extended to about 200 MeV for some of the cross section standards. Work on the standards evaluation has begun with an investigation of the completed experiments to determine uncertainties and correlations within and among data sets. Further work could lead to an improved evaluation procedure compared with that used in ENDF/B-VI. The status of the work on this evaluation will be discussed.