Analysis of the Effect of Cracking of Aluminum Coating on Cryogenic Target Sealing Film on Capsule and Ice Layer

In response to the cracking phenomenon of aluminum coating on the low-temperature target sealing film, the effects of aluminum coating cracking on the uniformity of the ice layer and the uniformity of the target temperature field were studied using experimental methods and CFD simulation methods. Through experimental methods, it was confirmed that the reason for the cracking of the aluminum coating on the sealing film is due to the high pressure of the filling gas. Three different crack locations were compared using CFD simulation methods. The results indicate that the cracking of the aluminum coating on the low-temperature target sealing film can lead to a decrease in the uniformity of the target temperature field, resulting in a deterioration of the uniformity of the ice layer. To avoid cracking of the aluminum coating, the pressure difference between the inside and outside of the sealing film should be controlled, and for experimental targets, it should be controlled within 10 kPa. The fracture mode of the aluminum coating caused by high filling gas pressure in the experiment should be overall cracking. The cracking of the aluminum film in the central area of the sealing film has the smallest impact on the uniformity of the target temperature field, while the cracking of the periphery has the greatest impact.