基于温度冲击的冷冻靶氘氘冰层结晶生长行为研究

Crystal Growth Technology of Deuterium-deuterium in Cryogenic Target Based on Temperature Shock

惯性约束聚变冷冻靶中氘氘(D2)冰层的质量对聚变实验的成功与否起重要作用。目前文献报道的制备冷冻靶D2冰层的方法并不具备好的可操作性,且技术、工艺不定型,制约了高质量冰层的形成。因此,本文采用将温度梯度、降温速率和温度冲击相结合的技术实现燃料冰层在靶丸内的均化。通过温度控制以及施加温度冲击可控地形成残留冰,并在残留冰的控制技术基础上,实现了高质量冰层的可控结晶生长。同时,研究了温度控制对靶丸内D2冰层品质的影响和D2冰层结晶生长的过程,并应用晶体生长动力学理论分析了D2冰层结晶生长行为。从背光阴影图像中的D2冰层亮环可知,D2冰层均匀度为85.2%、厚度为40.35μm、内表面粗糙度为2.15μm。本方法拓宽了超低温下D2冰籽晶控制、晶体生长技术,为DT冷冻靶中冰层均化打下了坚实基础,并形成了一定的技术储备。

The quality of deuterium-deuterium(D2)ice layer in inertial confinement fusion cryogenic targets plays a crucial role in the success of fusion experiments.At present,the methods reported in the literature for preparing D2 ice layer in cryogenic target do not have good operability,and the technology and process are indeterminate,which restricts the formation of high-quality ice layer.Therefore,in this paper,the technology of the combination of temperature gradient,cooling rate and temperature shock ice was used,and on the basis of the control technology of residual ice,the controllable growth of high-quality ice layer was realized.Meanwhile,the effect of temperature control on the crystallization quality of D2 fuel in target pellets and the crystal growth of process of D2 fuel at cryogenic temperature were studied.The crystallization behavior of D2 fuel was analyzed using the crystal growth morphodynanics theory.Analysis of the bright ring in the backlit shadow image shows that D2 ice layer uniformity is 85.2%,the thickness is 40.35μm,and the inner surface roughness is 2.15μm.This method broadens the technology of the control of D2 ice seed and crystal growth at cryogenic temperature,lays a solid foundation for DT layer,and forms a certain technical reserve.