Preparation and characterization of inertial confinement fusion capsules

The main point of inertial-confinement-fusion (ICF) lies on the concept that via capsule-based implosion fuel inside capsules can be pressured to high temperature, high density plasma to approach ignition. Capsules, taken as fuel containers and being related with hydrodynamic instability and compression symmetry during implosion, must meet some specifications on spherecity, wall-thickness, surface smoothness and doping level. In order to meet these specifications, a series of techniques are developed, such as microencapsulation technique, degradable mandrel technique and glow discharge polymerization method and dried gel method to prepare polymer capsules and hollow glass microspheres respectively. ICF capsules are relatively small, light, and fragile and possess smooth surfaces which are subject to deface, different techniques are developed to characterize the capsule profile, component , doping level and fuel density, such as contact X-ray radiography, wall-mapping technique and white light interferometry. These techniques make the preparation and characterization of ICF capsules, such as multilayer polymer capsules, hollow glass microspheres, poly-α-methyl styrene mandrel capsules and doped glow discharge polymerization capsules advance quickly in these years. These capsules succeed in implosion experiments held on 'SG' series facilities. (authors)