激光直接驱动内爆DT燃料面密度诊断

DT FUEL AREAL DENSITY DIAGNOSTIC IN DIRECT-DRIVEN IMPLOSIONS

在神光Ⅱ基频光直接驱动内爆实验中 ,利用CR39径迹探测器测量了DT靶丸释放出的 14MeV中子弹性散射后逃逸出燃料的反冲D核和反冲T核的数量 ,实现了激光聚变实验中燃料面密度〈ρR〉的诊断 .测量结果表明 ,靶面激光照射均匀度对压缩状态具有一定程度的影响 ,爆推靶〈ρR〉低于烧蚀靶〈ρR〉一个量级左右 ,表明烧蚀靶压缩情况比爆推靶好 。

The diagnostic of DT fuel plasma areal density in the direct-driven implosion experiments on SG-Ⅱ laser facility has been performed by measuring the number of recoil D and T produced by 14MeV neutron′s scattering. The particles of recoil D and T were detected by CR39 solid-state nuclear track detector. The experimental results indicate that the uniformity of laser illuminating affects the compression to a certain extent. The areal density of exploding pusher target is about one order lower than that of ablative-driven target. This means that the compression of ablative-driven target is better than exploding pusher target. There is a strong relationship between areal density and suprathermal electron heating.