Uniform coating of micro-spherical substrates to the precision required for fabricating fuel targets is a major challenge limiting the development of inertial fusion energy. Conventionally, spherical substrates have been coated through a process that exposes multiple randomly rolling spheres to a vapor stream. This approach has serious limitations since nearby spheres touch, collide, and experience slipping interaction leading to material wear and contamination of the coating with trap particulates.
This invention configures multiple spherical substrate targets to roll independently of one another. The spheres’ rolling motion is deliberately randomized to promote uniform coating while eliminating the interaction (rubbing, sliding) of adjacent spheres that is present in conventional sphere coating designs. The devices’ novel structure features enable the collimation of depositing species flux, improving the deposition energetics and ballistics and preventing the coating of the substrate holder surfaces. The devices also allow for the continuous removal of unwanted dust and particulates.
Current stage of technology development: TRL 2
LLNL has filed for patent protection on this invention.
• Scalable design.
• Eliminates defects and particulate inclusions generated by conventional techniques.
• Achieves higher degree of precision and uniformity not possible with current techniques.
• Works with a wide variety of substrates and coating materials.
• Fabricating precision uniformly coated microspheres
• Fabricating jewelry
• Fabricating precision, custom optical resonators
• Fabricating precision ball bearings
