Growth of a solid D-T ice and β-layering in the GDP capsule

Abstract

The most common way to make a high-quality ice layer that meets the requirements of inertial confinement fusion (ICF) is to follow the single crystal growing process under the condition of the heat of decay. We attempted to optimize a complete set of processes for the preparation of uniform D-T ice in a ICF target with a fill tube. During seed nucleation, we found that an appropriate temperature strategy can reduce the requirement for temperature stability in the capsule and improve the success rate of seed crystallization. During the initial stage of crystal growth, if the cooling rate is below 1mK/min, the thermal disturbance from the fill tube into the capsule can easily lead to ice melting. Beta-layering with constant temperature and temperature oscillations after crystal growth can further improve the Root-Mean-Square roughness of the inner surface.