基于蒙特卡罗-离散纵标方法的氘氚激光等离子体聚变反应率数值模拟  

Numerical simulation of deuterium-tritium fusion reaction rate in laser plasma based on Monte Carlo-discrete ordinate method

作　　者：陈忠[1,2] 赵子甲 吕中良 李俊汉 潘冬梅 Chen Zhong;Zhao Zi-Jia;Lü Zhong-Liang;Li Jun-Han;Pan Dong-Mei(School of National Defense Science and Technology,Southwest University of Science and Technology,Mianyang 621010,China;College of Liberal Arts and Science,National University of Defense Technology,Changsha 410073,China;University of Science and Technology of China,Hefei 230027,China)

机构地区：[1]西南科技大学国防科技学院,绵阳621010 [2]国防科技大学文理学院,长沙410073 [3]中国科学技术大学,合肥230027

出　　处：《物理学报》2019年第21期219-225,共7页Acta Physica Sinica

基　　金：西南科技大学博士基金(批准号:13zx7138);湖南省科技创新计划(批准号:2018JJ2473);国家自然科学基金(批准号:11475150,11475260);中国科学院中子输运理论与辐射安全重点实验室开放研究课题基金(批准号:NEUTRON201707);哈尔滨工程大学核安全与仿真技术国防重点学科实验室基金(批准号:HEUNSS18SF04);特殊环境机器人技术四川省重点实验室基金(批准号:17kftk01)资助的课题~~

摘　　要：惯性约束聚变(ICF)是实现受控热核聚变可能途径之一.聚变中子源项是氘氚激光等离子体物理设计与分析的重要参数之一,其准确性直接影响分析结果的可靠性.目前国内外对于ICF氘氚聚变反应产生的中子源项研究主要基于解析公式法,在温度和反应类型等方面适用范围有限.本文采用粒子云概念对氘、氚粒子云团开展了随机抽样与时空网格划分,然后基于麦克斯韦速率分布律对氘氚聚变反应开展了多普勒能量展宽效应分析与微分截面温度修正工作,耦合蒙特卡罗方法和离散纵标方法,开展了激光等离子体中D-T粒子云团聚变反应率的数值模拟工作.研究结果显示,与原核数据库截面相比,D-T,D-D,T-D截面经修正后多普勒温度效应显著.在20 100 keV的等离子体温度范围内,相较传统的解析公式法,本文模拟结果更符合最新的ENDF核数据库的氘氚反应截面数据,且与解析公式法结果在低能区存在较大误差,可能是计算方法不同与低温截面差异过大原因导致.Inertial confinement fusion(ICF)is one of the possible ways to realize controlled thermonuclear fusion.Thefusion neutron source term is one of the important parameters in the physical design and analysis of laserplasma.The accuracy of the fusion neutron source term directly affects the reliability of the analysis results.Atpresent,the neutron source term of deuterium-tritium fusion reaction in ICF is mainly based on formulamethod.It has limited applications in temperature and reaction type.Because of a large quantity of data,it isimpossible to simulate the fusion reaction of each particle.In this paper,the concept of particle cloud isintroduced,that is,the collection of the like particles with the same position and speed,and it is consideredthat the action of particle cloud is the same reaction.Because the particles should satisfy the Maxwell velocitydistribution at a certain temperature and the direction is all around the circumference angle,the collision crosssections between the incident particle and different target particles are different.Therefore,the design programtakes all the possible velocities,polar angles and direction angles,reads the collision cross sections betweendeuterium and tritium and makes corrections,and obtains the multi-temperature differential correction crosssections of deuterium and tritium fusion with Doppler energy broadening.On these bases,Monte Carlo methodand discrete ordinate method method are used.A numerical simulation program for the fusion rate of D-Tparticles in laser plasma is developed in this paper.It is found that there are significant differences between theDT,DD,TD cross sections and the original cross sections after Doppler broadening.In a range of plasmatemperature between 20 keV and 100 keV,the simulation results are more consistent with the cross section dataof ENDF/B-VI and ENDF/B-VII databases of deuterium-tritium fusion reaction than those from the analyticalformula method.There is a large error between the numerical simulation results and the analytical formulam

关 键 词：激光等离子体 氘氚聚变反应 微分截面温度修正 蒙特卡罗方法 离散纵标方法 

分 类 号：TL632[核科学技术—核技术及应用]