第Ⅵ和第Ⅶ副族稀有高熔点金属同位素快中子核反应激发函数研究

The accurate and reliable cross-section data induced by fast neutrons on rare refractory metal isotopes of Group ⅥB and Group ⅦB elements W, Mo, Re (which and their alloys have been widely used in the industries of electronic, atomic energy, aerospace and so on) are of important significance for the development of nuclear power and radiation resistance reinforcement. However, there are discrepancies in the experimental data of the cross sections obtained by various laboratories due to differences in experimental methods, equipments and datum processing methods, and there is no experimental cross-section datum in the experimental nuclear reaction databases for some nuclear reactions so far. Making use of the neutron generator of the China Academy of Engineering Physics as an experimental platform, this project will systematically research the cross sections of nuclear reactions induced by D-T fast neutrons on the isotopes of Group ⅥB and Group ⅦB elements W, Mo, Re by using activation technique. At the same time, the excitation functions of these reactions will be calculated and evaluated on the basis of statistics and exciton theory model, and the conformity and the discrepancies between the obtained data and the existing data in the experimental nuclear reaction databases and the recommended values in the evaluated nuclear reaction libraries will be analyzed and found by comparing. For the nuclear reactions which there is no experimental cross-section datum in the experimental nuclear reaction databases will be measured and be given reliable cross-section data.

第Ⅵ和第Ⅶ副族稀有高熔点金属钨、钼、铼及其合金被广泛用于电子、原子能和航空航天等工业领域，这些金属同位素精确可靠的快中子核反应截面数据对核能开发和抗辐射加固等有重要意义。然而，由于不同实验室所用实验方法、仪器设备和数据处理方法等不同，获得的核反应截面实验数据之间往往存在很大分歧，有些核反应至今无截面实验数据。本项目以中国工程物理研究院的中子发生器为实验平台，用氘-氚快中子活化第Ⅵ和第Ⅶ副族钨、钼、铼的天然同位素，用高分辨率的高纯锗探测器对核反应生成核活度进行测量，从而对快中子引起钨、钼、铼同位素核反应截面进行系统的实验研究，同时结合统计与激子理论模型对其激发函数进行计算与评价，与核反应实验数据库中已有的数据和核反应评价数据库的推荐值进行对比，分析数据的符合性，找出数据分歧的原因并进行矫正；而对于在核反应实验数据库中尚无实验数据的核反应进行探索性测量，并给出可靠的核反应截面实验结果。

钨、钼、铼同位素精确可靠的快中子核反应截面实验数据，是核反应堆设计、核能开发和核技术应用的重要基础数据。本项目针对钨、钼、铼同位素至今在国内外没有快中子核反应截面实验数据，或虽有实验数据但数据少且有较大分歧的10个核反应进行系统的实验研究，并结合核反应理论模型，用国际著名的核数据理论模型计算程序Talys-1.9对其激发函数进行模拟计算，获得了项目任务书中5个核反应、19个中子能量点的截面实验数据，以及这5个核反应从阈能到20MeV能区的中子核反应激发函数曲线；获得了任务书中另外5个核反应，从阈能到20MeV能区的中子核反应激发函数曲线。此外，还获得了任务书以外29个核反应、100多个中子能量点的截面实验数据。这些核反应截面实验数据和它们的激发函数曲线，对聚变装置设计、核反应实验数据库和评价数据库的建设、核反应理论模型的完善，以及相关科学与技术的研究等有重要意义。