Temperature effects on the behavior of liquid hydrogen isotopes inside a spherical-shell inertial confinement fusion target

An important task in the inertial confinement fusion (ICF) research is to fabricate targets which will result in high fusion yield. A spherical shell containing a uniform liquid (or solid) deuterium-tritium (D-T) layer on the inner surface represents one of the most popular high-gain ICF target configurations. The uniformity of the D-T layer is a must to achieve the desired high gain. This work studies the temperature effects on the formation of a uniform liquid hydrogen layer inside a spherical glass shell (SGS). The profile of the liquid layer is first investigated for an isothermal case. An equation suitable for describing the profile is derived by including the London-van der Waals attractive forces between the liquid and substrate molecules. Two theoretical models are then established to explain the changes in the liquid layer profile under the influence of a vertically applied temperature gradient. It is found that a uniform liquid layer of single-component hydrogen can be created and maintained by an appropriate negative temperature gradient, namely, a temperature gradient which will keep the top of the SGS cooler than the bottom