Affordable and lightweight high-resolution x-ray optics for astronomical missions

Abstract

Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major xray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

Next generation x-ray optics for astronomy: high resolution, lightweight, and low cost

“…Many considerations have been taken into account to arrive at the above technology paradigm [19][20][21][22][23][24][25][26][27] , both for achieving the best possible science performance and for the purpose of practical implementation in terms of schedule and cost, as well as post-launch operations. This paradigm has many advantages.…”

European x-ray optics for next generation space observatories

“…SPO has been selected by ESA as the baseline technology for Athena, but slumped glass optics have been investigated as a backup technology [10] in Europe. Slumped Glass Optics from the US are used for the NuSTAR small explorer mission [11] and further developments to improve the optical performance for high resolution x-ray observatories are being undertaken by NASA [12].…”

Gas bearing slumping and figure correction of x-ray telescope mirror substrates

“…Forming a substrate with good figure may be achieved by slumping glass 2,3,4,5 , or grinding and polishing silicon 2 . Error correction may potentially be achieved using either stress-based methods to bend the substrate to the desired shape (e.g., magneto-strictive films 6 , ion implantation 7 , or piezoelectric films 5 ); or direct methods, such as differential deposition 8,9 , to remove/add material to achieve the desired surface height.…”