Fabrication of Surface Bumps on a Capsule to Simulate Fill Tube Mass Defects

Precision single bumps were deposited on the surface of ICF capsules to simulate the hydrodynamic instability caused by a fill tube. The bump is fabricated by placing an aperture mask on the capsule and coating plasma polymer through the aperture. The apparatus and procedures used to align and hold the shell for coating are described. Bumps were made having a width of about 50 (mu)m and from 1 to 10 (mu)m in height. The bumps were characterized using interference microscopy and AFM.