基于场反位形的磁约束氘氘脉冲聚变中子源方案设计

Project Design of a Pulsed D-D Fusion Neutron Source Based on Field Reversed Configuration

聚变中子源可以真实反映材料在聚变中子辐照下的特性变化,对于开展聚变堆材料测试具有重要意义。基于加速器打靶原理的国际聚变材料辐照装置(IFMIF)与理想聚变中子源在聚变中子能谱等方面仍有一定差异,因此需对聚变中子源方案进行新的思索。本文围绕磁约束聚变中子源开展了磁场位形、加热方案设计与相关计算,分析了场反等离子体在两级级联磁压缩后的等离子体温度、密度演化过程及相应的中子产额,并研究了考虑双流体效应与有限拉莫尔半径效应后场反等离子体倾斜模、旋转模等磁流体不稳定性的抑制情况,最终给出了氘氘脉冲聚变中子源的关键物理参数。研究结果表明,该中子源有望获得年均2 MW/m2以上的高通量密度的聚变中子,能够满足商业聚变示范堆材料测试要求;经功率估算显示,基于场反位形进行两级级联磁压缩的新型聚变中子源方案还具备成为氘氘脉冲聚变能源的应用前景。

The fusion neutron source is of great significance for conducting material testing for future fusion reactors,as it can genuinely reflect the change of material properties under fusion neutron irradiation.The International Fusion Materials Irradiation Facility(IFMIF)is an accelerator-driven neutron source.It still has some differences from the ideal fusion neutron source in terms of fusion neutron energy spectrum,which has led to the reconsideration of the fusion neutron source approach.In this paper,the magnetic field configuration,heating scheme design,and related calculations are carried out regarding the fusion neutron source.The plasma temperature,density evolution process,and the corresponding neutron yield of the field reversed configuration(FRC)plasma after two-stage cascade magnetic compression are analyzed,and the suppression of the magnetic fluid instabilities such as tilted and rotating modes of the FRC plasma after considering the two-fluid effect and the finite Larmor radius effect are studied.The fundamental physical parameters of the fusion neutron source are finally given.The calculation results show that the neutron source is expected to obtain fusion neutrons with an annual average power density higher than 2 MW/m2,which can meet the requirements of material testing of the demonstration reactors(DEMO).The power estimation also shows that the scheme has the potential to become an energy source based on the pulsed deuterium-deuterium fusion.