Using ion implantation for figure correction in glass and silicon mirror substrates for X-ray telescopes

摘要

Ion implantation is a method of correcting figure errors in thin silicon or glass substrates. For future high-resolution, high-throughput x-ray observatories, such figure correction may be critical for thin mirror substrates. Ion implantation into both glass and silicon results in surface stress, which bends the substrate. We demonstrate that this stress may be used to improve the surface figure of flat glass wafers. We then describe three effects of ion implantation in glass and silicon. The first effect is the stress resulting from the implanted ions, and the implications for figure correction with each material. Second, each material studied also shows some relaxation after the ion beam is removed; we report on the magnitude of this relaxation and its implications. Finally, the surface stress may affect the strength of implanted materials. We report on ring-on-ring strength tests conducted on implanted glass samples.