Forming uniform HD layers in shells using infrared radiation

Generating a volumetric heat source in solid deuterium hydride, HD, allows the formation of a spherical crystalline shell of HD inside a transparent plastic shell. Pumping the infra-red (IR) collisionally induced vibration-rotation band of solid HD contained inside a transparent plastic shell generates the volumetric heat source in the HD lattice. HD layers 150 - 250 mu m thick formed near the triple point have a surface roughness rms between 1-3 mu m and become rougher with decreasing temperature. Solid growth dynamics have a significant impact on the quality of the resultant layer.