D-D/D-T中子能区钍-232的中子核数据测量研究

钍-232中子反应截面和裂变产额数据是钍铀循环核燃料增值与嬗变研究的重要基础。目前基于熔盐堆的钍铀循环还没有专用核数据库，国际上的实验和评价数据在精度上也远达不到要求。本项目拟解决影响实验测量精度的系列问题，以兰州大学的D-D/D-T强流中子发生器和低本底HPGe伽玛谱仪为基础，利用活化法精确测量3MeV、14MeV能区中子引起的232Th(n, γ)233Th和232Th（n，2n）231Th的反应截面，并与已有的实验数据和评价数据进行比较分析，找到分歧原因并进行修正，给出1～20MeV区间的中子激发函数曲线。采用直接γ能谱法开展3MeV和14MeV中子诱发的232Th裂变产额测量。项目的研究成果将对我国自主开展系统性的数据评价和加工，对理论计算进行实验检验和验证提供可靠依据。为钍基熔盐堆核能系统（MRS）研究项目的顺利开展奠定基础。

As the foundation of nuclear fuel proliferation and transmutation research, the neutron reaction cross sections and fission yield of 232Th are very important for the Thorium-Uranium fuel cycle. At present there were no special database on the Thorium-Uranium fuel cycle. Meanwhile, the existing data are insufficient or lacking and severe discrepancies between the data from the main neutron data libraries exist. This project will make use of the intense D-D/D-T neutron generator and high resolution HPGe γ spectrometer at Lanzhou universty. On the one hand, the 232Th (n, γ) 233Th and 232Th（n，2n）231Th reaction cross-sections at neutron energies 3MeV and 14MeV will be determined using activation and off-line γ-ray spectrometric technique. On the other hand, the direct γ spectroscopy method will be adopt to measure the fission product yields of 232Th producted by the d(d, n)and T(d, n) mono-energetic neutron sources. The research achievements will provide reliable basis for our system data evaluation work and experimental test, ensure the smooth development of the Thorium Molten Salt Reactor system research (MRS).