激光烧蚀R-T不稳定性研究中的双模式CH平面调制靶制备

为研究同一次激光驱动下初始扰动幅值不同时瑞利-泰勒（Rayleigh-Taylor，R-T）不稳定性非线性演化的差别，采用单点金刚石车削技术，以太空铝合金为材料加工了两侧具有不同扰动幅度的模板。然后利用旋转涂覆工艺将模板表面的扰动图形转移至CH薄膜表面，制得了双模式CH平面调制靶。通过QC-5000型光学显微镜、alpha-step 500型台阶仪、NT1100型白光干涉仪等对铝合金模板及CH平面调制靶的周期、振幅等参数进行测量。结果表明：模板和CH平面调制靶的两侧均具有不同的扰动图形；两侧扰动的波长相同，均为54 μm左右，但振幅不同，分别为4.8 μm和1.9 μm；两侧扰动的平衡位置在同一水平面，调制图形的各项参数与设计值基本一致，模板表面的扰动图形成功地转移到了CH薄膜表面，获得了满足R-T不稳定性实验需求的双模CH平面调制靶。

Fabrication of Dual-mode CH Planar Perturbation Target for Laser Ablative R-T Instability Experimental Study

In order to study the difference of the nonlinear evolution of Rayleigh-Taylor instability under the same driven condition while the initial perturbation amplitude was different. The aluminum alloy templates with different perturbation amplitudes at two sides of its surface were fabricated via single-point diamond turning technology. Then the perturbation pattern was transferred from the template to the CH film via spin coating process, and the dual-mode CH planar perturbation target was prepared. Parameters of the aluminum alloy template and the CH target, such as the perturbation period and perturbation amplitude were characterized by QC-5000 tool microscope, alpha-step 500 surface profiler and NT1100 white light interferometer. Results show that both the template and the CH planar perturbation target have different perturbation patterns at two sides of their surfaces. The perturbation periods at two sides are both 54 μm, while the perturbation amplitude is 4.8 μm and 1.9 μm at the left and right sides, respectively. The equilibrium position of the perturbation pattern at two sides is in the same horizontal plane. Parameters of the template and the target are consistent with the designed value, the perturbation pattern is transferred from the aluminum alloy template to the CH film successfully, and the dual-mode CH planar perturbation target which meets the requirements of the Rayleigh-Taylor instability experiment was fabricated.