Micromachining applications for ICF target fabrication

Abstract

Micromachining techniques used in Inertial Confinement Fusion (ICF) target fabrication encompass laser drilling, single point diamond turning, and plasma as well as chemical etching. These techniques have been developed by several laboratories to produce target components with tolerances and surface finishes in the micron to submicron regime. Some of the spherical target components produced by micromachining techniques include free standing hemispherical shells (diameters 50–500 μm), micron-sized holes in thin glass shells, and plastic-coated glass microballons with surfaces which have been smoothly machined to remove a mounting stalk. Planar targets and components produced by these techniques include small disks and washers of thin brittle materials. Micromachining techniques are also used to fabricate diagnostic instruments such as x-ray mirrors and zone plates. This paper will examine micromachining techniques used to produce target components and diagnostic instruments. The relationship of each micromachining technique to presently used target configurations will also be discussed.