磁化套筒惯性聚变中端面损失效应的一维唯象模型与影响分析

得益于激光预加热和轴向磁场的作用,磁化套筒惯性聚变(magnetized liner inertial fusion,MagLIF)构型理论上能有效降低聚变实现的难度,具有极大的应用潜力.本文选择MagLIF过程中伴随激光预加热所必然存在端面损失效应作为研究目标,搭建了能够描述几何参数与腊肠不稳定性等高维效应的一维唯象物理模型,并分别通过与二维流体动力学程序和国外同类程序的计算对比完成参数拟合校验;在此基础上,获得端面损失效应对MagLIF内爆过程及预加热效果的影响规律.计算结果表明:不同喷射半径下MagLIF负载在内爆过程的绝大多数时间内保持了相近的流体动力学演化过程,并在迟滞阶段经历了相同的质量损失比例,且考虑端面效应后得到的预加热和内爆产额相对变差,但却不改变规律性的趋势.所建立的模型与结论有助于加深对MagLIF预加热和端面损失过程中物理图像的认知和理解.

One-dimensional modeling and simulation of end loss effect in magnetized liner inertial fusion

Benefiting from laser preheat and magnetization,magnetized liner lnertial fusion(MagLIF)has a promising potential because theoretically it can dramatically lower the difficulties in realizing the controlled fusion.In this paper,the end loss effect caused by laser preheat in MagLIF process is chosen as an objective to explore its influences,and a one-dimensional and heuristic model of this effect is proposed based on the jet model of ideal fluid,in which the high-dimensional influences,such as geometric parameters and sausage instability,are taken into consideration.To complete the verification progress,the calculation results of one-dimensional MIST code and two-dimensional programs TriAngels and HDYRA are compared,and the application scopes of this heuristic model are discussed and summarized.Based on this model,the key parameters and influences of the end loss effect on the MagLIF implosion process and pre-heating effect are obtained.The calculation results show that the MagLIF load maintains a similar hydrodynamic evolution process in most of the implosion processes with different laser entrance radii,and experiences the same percentage of mass(~16%)lost during stagnation stage.With the same driving current,the fuel temperature will rise higher in the model with more mass losing,so the fusion yields do not change too much.The mass loss ratio seems to play a dominant role.It is recommended to design the laser entrance hole as small as possible in the experiment to increase the yield.The predictions obtained after considering the end loss effect lower the preheating temperature and fusion yield,but no change happens to the regularity trend.As the liner height increases,the preheating temperature,peak current,fuel internal energy,and fusion yield each still show a monotonically downward trend.Therefore,under the premise of fixed driving capability and laser output capability,it is suggested that the liner height in MagLIF load design should be as short as possible.The established heuristic model and conclusions are helpful in better understanding the physical mechanism in the process of MagLIF preheat and end loss.