Development of diffraction-limited Wolter x-ray telescope optics

Over the last two decades, surface figure errors of thin-shell Wolter-Schwarzschild X-ray mirrors, under development by the Goddard X-ray mirror group and MIT, have steadily dropped, now trending into the sub-1 arcsec domain and even exceeding the quality of Chandra mirrors. At this rate, within a decade, single mirror pairs should reach a diffraction-limited resolution determined solely by the X-ray wavelength, bottoming out near 0.1 arcsec for 1 keV X-rays. Pushing below this resolution barrier, into the astrophysical domain at the milli- to micro-arcsec (mas to uas) scales, will require coherently combining beams from multiple mirror pairs, which is beyond current capability. Unlocking the science bonanza below 0.1 arc sec will require new metrology tools for Wolter mirror polishing, alignment, assembly and test, driving surface and alignment accuracy into the sub-nanometer domain. We propose to develop and apply these tools to fabricate and align prototype mirrors, and demonstrate their performance with X-rays. We recently published a new concept in diffraction-limited X-ray telescope design, based on extensions of the proven Wolter Type 2 prescription. This breakthrough design features a wide bandwidth (0.1-10 keV) and large collecting area in a compact assembly that scales naturally from the mas to uas domains. Although metrology to support telescopes of this power will be challenging, recent advances in sub-nanometer mirror metrology, including (1) “absolute” shearing interferometry, (2) bright, coherent, table-top X-ray sources enabling at-wavelength X-ray mirror interferometry, and (3) short coherence-length visible light lasers for mirror alignment, will open the door to realizing this powerful new class of telescopes. To our knowledge, these new techniques, many recently developed by the semiconductor industry, have not yet been applied to Wolter telescope optics, creating a rich opportunity that portends rapid advance. In addition to enabling new mission concepts targeted to the 2030+ time frame, improved mirror metrology will also have a direct impact on near-term mission concepts such as STAR-X, AXIS and Lynx, helping to widen fabrication process windows and reduce schedule risk. We propose a three-step research plan designed to reduce risk and cost as we develop, explore and apply these new techniques to prototype mirrors via fabrication, alignment and X-ray tests. Step 1. Extend APRA-funded research already underway to increase the accuracy of the Fizeau interferometers that underpin the Wolter mirror polish-metrology cycle. Step 2. Demonstrate diffraction-limited mirror performance in the lab using a zone plate X-ray microscope and lateral shear interferometer. Step 3. Develop a multiple-mirror alignment technique using a short-coherence-length visible light laser and demonstrate coherent superposition of X-ray beams.

The Astrophysics Research and Analysis program (APRA) supports suborbital and suborbital-class investigations, development of detectors and supporting technology, laboratory astrophysics, and limited ground-based observing. Basic research proposals in these areas are solicited for investigations that are relevant to NASA's programs in astronomy and astrophysics, including the entire range of photons, gravitational waves, and particle astrophysics. The emphasis of this solicitation is on technologies and investigations that advance NASA astrophysics missions and goals.

This is a mature technology (TRL 7+) — the realistic path in is usually NASA's Technology Transfer Program: licensing an existing NASA patent, or a Space Act Agreement to use NASA facilities/expertise directly. NASA also runs a startup licensing program with no upfront fee for companies formed to commercialize a specific NASA technology.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.