结构效应对核子引发{6,7}Li核反应产物的影响研究

核子引发{6,7}Li反应对核工程中的氚增值比、热分布和结构材料的辐射损伤等都有着重要的影响，对核工程的设计制造等具有重要的应用价值。目前国内外仍没有成熟的模型理论能同时定量给出核子引发{6,7}Li反应的出射中子、质子、氘、氚、3He及4He双微分截面，对6Li(n,t)α造氚反应截面远大于弹性截面亦缺乏理论解释。本项目拟基于中子引发轻核反应的统计理论，研究低能核子引发{6,7}Li反应及不同反应过程中剩余核的结构特性对最终反应产物的影响，考虑入射道和不同出射道的库伦位垒效应以及各种复杂粒子在靶核及剩余核中的预形成几率，在严格保证能量、角动量及宇称守恒的情况下，发展一个能很好地描述核子引发{6,7}Li核反应机制的模型，定量给出所有反应产物的双微分截面，以及中子入射能量小于3MeV情况下无阈的造氚反应6Li(n,t)α的反应截面及氚角分布。

The neutron- and proton-induced {6,7}Li reactions have a significant impact on tritium breeding ratio, nuclear heating distribution, radiation damage of structural materials in nuclear engineerings. In view of the facts that there are still no perfect theories which can calculate simultaneously and quantitatively the double-differential cross sections of neutron, proton, deuteron, tritium, 3He, and 4He from reactions of {6,7}Li induced by nucleons and the differential cross section of (n, t) reaction, this project will focus on the structural properties of target nuclei {6,7}Li and the corresponding residual nuclei in different reaction processes. Taking into account the coulomb barriers of the incoming channel and different outgoing channels, the pre-formation probabilities of various composite particles in target nuclei and residual nuclei, and keeping strictly conservations of energy, angular momentum, and parity, we will further develop a theory that can well describe the mechanism of nucleon-induced {6,7}Li reactions to calculate the double-differential cross sections of all the reaction products on the basis of the statistical theory for neutron-induced reaction of light nuclei. Meanwhile, a new method will be devoloped to describe the cross section and angular distribution of {6}Li(n,t) reaction below 3MeV with no threshold energy.