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

Abstract

The capability of an X-ray telescope depends on the quality of its mirror, which can be characterized by four quantities: point-spread-function, photon-collecting area, field of view, and energy bandwidth. In this paper, we report on our effort of developing an X-ray mirror technology that advances all of those four quantities for future X-ray astronomical missions. In addition, we have adopted a modular approach, capable of making mirror assemblies for missions of all sizes, from large missions like Lynx, to medium-sized Probes like AXIS, TAP, and HEX-P, to Explorers like STAR-X and FORCE, and to small sub-orbital missions like OGRE. This approach takes into account that all X-ray telescopes must be spaceborne and therefore require their mirror assemblies be lightweight. It is designed to make use of modern mass production techniques and commercial off-the-shelf equipment and materials to maximize production throughput and thereby to minimize implementation schedule and costs.

Performance Testing of a Large-Format X-ray Reflection Grating Prototype for a Suborbital Rocket Payload

“…The assembled spectrometer was constructed in the PANTER test chamber and consisted of three main components: a mono-crystalline silicon Wolter I-type (Wolter, 1952) focusing optic (Zhang et al, 2019b), an OGRE reflection grating prototype, and a detector at the focal plane. The quasi-collimated light from the source end of the facility was incident first on the focusing optic.…”

“…Mono-crystalline silicon optics are an X-ray optics technology developed at NASA Goddard Space Flight Center (Zhang et al, 2019b). The mirrors are produced from a block of single-crystal silicon, which allows them to theoretically be manufactured free of internal stresses for improved mirror performance.…”

“…In addition to these proposed missions, monocrystalline silicon X-ray optics will also be used on OGRE (Donovan et al, 2019). To date, the technology has produced single-shell Wolter I-type optics with half-power diameters of < 1.3 arcsec (Zhang et al, 2019b). The mono-crystalline silicon optic used for this test campaign was a single-shell Wolter I-type optic with a radius at the paraboloid-hyperboloid intersection node of 156 mm and a focal length of ∼ 8.4 m for a source at infinity.…”

A comprehensive line spread function error budget for the Off-plane Grating Rocket Experiment

“…The x-ray optic on board the OGRE spectrometer will be a monocrystalline silicon x-ray optic assembly developed by NASA GSFC. 2 The optic assembly will consist of 12 Wolter I-type 5 (paraboloid + hyperboloid) mirror shells with radii from r 0 ¼ 162. .364 mm and a common focal length of Z 0 ¼ 3500 mm.…”

“…The development of the OGRE optic assembly is led by NASA GSFC. 2 Since this component is manufactured externally, a detailed error analysis of this component is beyond the scope of this error budget; however, similar error budgets for monocrystalline optic assemblies have been developed for other x-ray missions such as Lynx. 9 The presented error budget only considers the final performance of a 60-deg azimuthal section of the OGRE optic assembly in the dispersion and cross-dispersion directions.…”