激光聚变靶设计中参数不确定性指标的线性近似法

Linear approximation method to determine parameter uncertainty indexes in target designing for laser fusion

激光聚变的点火对实验、器件、制靶及诊断等各方面的控制能力都有很高的要求。随着实验逐步趋近点火设计,实验的精密化要求也逐步提高。精密化实验要求靶设计不仅给出激光能量、靶尺寸、气压等参数,还需要给出这些关键参数的不确定性指标要求。因此,获得这些不确定性指标也成为靶设计的主要内容之一。针对如何在实验设计中更为方便有效地获得参数的不确定性指标问题,通过理论结合数值模拟研究给出了一种基于线性近似的方法。这一方法综合考虑各种关键参数变化对实验结果的影响,平衡器件、制靶等对各种参数的控制能力,来获得参数的不确定性指标。以一个气体靶设计为例,通过数值模拟来展示这种方法的使用。结果表明,这一方法可以在显著降低工作量的情况下有效地获得实验设计的参数不确定性指标。

Laser fusion ignition requires strict control over laser facility,target quality and diagnosis precision in experiments.With the experiments approaching ignition regime,the requirement of precision is increased.In the precision experiments,the target design should determine not only the parameters such as laser energy,target dimensions and gas density,et al,but also the uncertainty indexes of these important parameters.Hence it is important for target design to obtain the uncertainty indexes of parameters.This paper investigates the method to effectively obtain the uncertainty indexes in target design.The method is presented by theoretical analysis based on linear approximation,and takes into account the difference of the control abilities of different parameters.This paper also shows an example of the application of this method to a gas-filled target design.It is indicated that the parameters uncertainty indexes can be effectively specified in target design by this method with greatly reduced workload.