不同控温过程下冷冻靶冰层结晶生长行为研究

Study on crystal growth behavior of deuterium ice layer of cryogenic target temperature control process

为制备满足物理实验要求的冷冻靶氢同位素冰层,需控制冰结晶生长过程,实现燃料的单晶生长,由此减少影响冰层均匀性及晶体缺陷。采用数值模拟方法研究冷冻靶温度场,通过可见光背光阴影成像技术在线表征了低温下靶丸内氘(D2)的结晶生长行为。结果表明:当降温速率为0.4 K/min时,在靶丸内可重复形成D2籽晶;通过优化控温过程,可显著降低D2晶体生长过程中形成的缺陷。

In order to prepare the frozen deuterium(D2)ice layer of cryogenic target that meets the requirement of physical experiments,it is necessary to control the ice crystal growth process to achieve single crystal growth of the fuel,thereby reducing the influence of ice layer uniformity and crystal defects.In this work,the numerical simulation method was used to study the temperature target.Backlit shadowgraphy was used to characterize the crystal growth behavior of D2 in the target at cryogenic temperature.The results show that when the cooling rate reaches 0.4 K/min,D2 seed crystal can be formed repeatedly in the capsule;the defects formed during the growth of D2 crystal can be significantly reduced by optimizing the temperature control process.