Ablation layer coating of mechanically nonsupported inertial fusion targets

Autor: R. Q. Gram, M. Wittman, J. F. Mason, H. Kim
Rok vydání: 1986
Předmět:
Zdroj: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 4:1145-1149
ISSN: 1520-8559
0734-2101
DOI: 10.1116/1.573427
Popis: Ablation layers are deposited on DT‐filled glass microballoon targets by a parylene coating scheme while the targets are bounced on the surface of a mechanical resonator. Optimum bouncing is achieved with the resonator surface moving with a peak vertical velocity of ∼3 cm/s at a frequency much greater than the bounce frequency of the targets. The resonator, a solid cylinder of high‐Q material, uses a longitudinal mode of vibration to achieve vertical motion, which is uniform over its surface. A flexural mode of the cylinder is used for dislodging targets which have become stuck. In their natural state, the targets become charged triboelectrically and by the beta emission from the tritium decay. The adhesion of these charged targets is eliminated by creating a low power plasma in the bouncing region. Real time monitoring and control of coating thickness are achieved by use of a laser reflectometer. Coatings are examined with electron microscopy and x‐ray radiography.
Databáze: OpenAIRE