X-ray Multilayers for Next-Generation Astrophysics Missions

Project Overview

In this work, we proposed to demonstrate the feasibility of high-reflectivity multilayer coatings that will enable next-generation astrophysics missions in the x-ray region (2 - 7 nm wavelengths) where currently high-performance coatings largely do not exist. This paucity is due to multilayer interfacial effects that severely reduce the coating reflectance; our approach was based on understanding these interfacial effects and on tailored process modifications to control and minimize them. The experimental validation of our approach was made difficult by issues with our multilayer deposition tool, requiring reducing the scope of the project to the study of Chromium-Carbon (Cr/C) multilayers only. This work produced Cr/C multilayers with a relative increase in reflectivity by up to 13% compared to previous work. The resulting multilayer coatings will be a key, mission-enabling capability, towards investigating the polarization of accreting supermassive black holes in active galactic nuclei.

Mission Impact

This project supports the development of science and technology tools and capabilities in the area of Space Science and Security to meet future national security challenges. This project also supports semiconductor-related technologies (a national priority) and several other Lawrence Livermore National Laboratory Core Competencies by producing fundamental knowledge related to interactions of x-rays with matter and nanoscale thin film physics.