Abstract: To quantitatively control the aspect ratio of hollow glass microspheres(HGMs)for inertial confinement fusion(ICF)targets,a model was developed to describe the relationship between HGM aspect ratios and compositions and pressures of furnace gas,based on the process analysis of transformation mechanism from gel microspheres to HGMs in the drop-tower furnace.Furthermore,the mean diameters and aspect ratios of HGM batches under different compositions and pressures of furnace gas were experimentally investigated.The results showed that the shell-blowing process from the initial molten glass bubble to the resulting liquid HGM could be regulated by the partial pressures of argon gas in the furnace atmosphere,and therefore the diameters and aspect ratios of HGMs could be quantitatively controlled by the partial pressure of argon gas in the furnace atmosphere.However,it was infeasible to produce large-diameter HGMs with target quality by simply reducing the partial pressures of argon gas to zero.To meet the stringent requirements of ICF targets,special furnace gases with enough partial pressures of helium gas must be used to obtain high quality HGMs with good sphericity,surface finish and high yield.Except for the extreme operation conditions of excessively high(>0.08 MPa)or low(<0.01 MPa)partial pressures of argon gas in the furnace atmosphere,the predicted values of the model proposed in this work agreed well with the experimental results.

Key words: hollow glass microsphere, aspect ratio, dried-gel method, inertial confinement fusion, target fabrication

摘要： 为实现对惯性约束聚变(ICF)靶用空心玻璃微球(HGM)纵横比的调控,基于对干凝胶法制备HGM炉内成球过程的分析,建立了HGM纵横比的定量控制模型,实验研究了载气组分和压力对HGM直径和纵横比的影响。结果表明:通过调节载气中氩气分压可以控制熔融玻璃液泡的膨胀程度,从而定量控制最终HGM的直径和纵横比。但是,通过大幅度降低载气中的氩气分压来提高HGM半径和纵横比是不可行的。为提高载气的传热能力,确保HGM球形度、表面粗糙度和合格率满足ICF制靶的要求,必须在载气中添加一定分压的氦气。除部分极端工艺条件外,提出的HGM纵横比控制模型预测值与实验结果吻合良好。

关键词: 空心玻璃微球, 纵横比, 干凝胶法, 惯性约束聚变, 靶制备