D-D/D-T快中子诱发铀235,238活化截面与裂变产额实验研究

铀235和238的中子核反应数据是快中子增值堆（FBR）、加速器驱动次临界反应堆核能系统（ADS）和钍基熔盐堆（TMSR）等核能利用的关键数据。现有相关数据库还不够完善，最新的测量和评价数据精度上也达不到应用需求。本项目拟采用蒙特卡洛方法模拟快中子诱发铀同位素的核反应过程，分析解决影响实验测量精度的关键因素；依托兰州大学ZF-400型强流中子发生器和中国原子能科学研究院的CPNG-600高压倍加器，利用中子活化和离线伽马能谱法精确测量2.5MeV和14MeV能区快中子诱发铀235和238的(n,γ)与(n,2n)等反应道活化截面，与已有实验和评价数据比较，找出分歧并进行修正；同时采用直接γ能谱法测量铀235和238在多个能点的裂变产额质量分布，测量精度达到国际先进。研究成果将为完善我国中子核反应数据库、自主开展相关核数据评价、发展核反应模型理论和新型反应堆开发提供必需的高精度数据。

The data of nuclear reaction for Uranium isotopes induced by fast neutrons is fundamental for the research of Fast Breeder Reactor (FBR)、Accelerator Driven Sub-critical System (ADS) and fuel increment and transmutation in Thorium based Molten Salt Reactor (TMSR). At present the related database is not perfect and the accuracy of the existing experimental data are insufficient or lacking. Meanwhile, the evaluated data from the neutron data libraries are still far from meeting the application demand. .This project is proposed to simulation the fast neutron induced nuclear reaction process of Uranium isotopes using the Mento-Carlo method, analysis the key factors which affecting the measurement accuracy. Based on the CPNG-600 Cockcroft-Walton accelerator at China Institute of Atomic Energy (CIAE) and the ZF-400 Intense Neutron Generator at Lanzhou University, the activation cross sections of (n,γ), (n,2n) reactions as well as the fission product yields of 235,238U will be measured using the activation method and off-line γ-ray spectrometric technique. The research achievements will complementing of the nuclear data libraries, provide reliable bases for independent nuclear data evaluation, model calculations and nuclear power development of China.