大型激光原型装置低燃料面密度诊断技术

Measurement of fuel areal density for large laser prototype facility

由于某大型激光原型装置内爆实验的燃料面密度很低,提出了利用充纯D燃料内爆产生的初级DD中子和次级DT中子的产额比值来诊断燃料面密度的方法。在该原型装置的首轮内爆实验中,利用研制的高灵敏塑料闪烁体探测器对初级DD中子产额和次级DT中子产额进行了测量。通过实验发现,当初级DD中子产额高于108时,可以测得次级DT中子实验数据。建立了均匀内爆模型,用初级和次级中子产额比值法对燃料面密度进行计算,获得的该原型装置首轮内爆实验燃料压缩的平均面密度小于4.0 mg/cm2。

In the first run of the large laser prototype facility,two sensitive plastic scintillation detectors were used to measure the primary neutron yield and the secondary neutron yield in the implosion experiments.When the primary neutron yield exceeded 108,the secondary neutron yield could be gained.Under the low fuel areal density,the ratio of the secondary neutron yield to the primary neutron yield was used to calculate the fuel areal density.This is the first time that the values of fuel areal density was obtained through this way in China,and the fuel areal density is lower than 4 mg/cm^2.