High quality hollow diamond shell for inertial confinement fusion

Diamond shell with outstanding physical and chemical properties is a promising ablator material for the inertial confinement fusion (ICF) application. In this paper, high-quality hollow diamond shells were synthesized through multiple steps. Microstructure, chemical bonding, sphericity, wall thickness uniformity, and mass density of the diamond shell were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray camera, respectively. Results show that the diamond shell composed of large amount of sp3 bonded carbon was very compact and free of cracks. The sphericity and wall thickness uniformity were about 93 % and 95 %, respectively. Mass density of the diamond film was higher than 3.2 g/cm3 when 1 vol% of CH4 was introduced. At relative low CH4 concentrations, secondary nucleation sites emerged at the grain boundaries and on the faceted crystal plane of micron-sized grains.