Design progress on the Lynx soft x-ray critical-angle transmission grating spectrometer

摘要

Lynx is one of the Surveyor-class mission concept studies for the 2020 Astrophysics Decadal Survey. One of the nominal science instruments for Lynx is a soft X-ray grating spectrometer and our design using critical-angle transmission (CAT) gratings can achieve the required resolving power R < 5000 and effective area < 4000 cm2. We presented an initial optical design in Gunther and Heilmann 2019 (JATIS 5, 02), and identified several points where additional ray-trace work can improve our design of the instrument. We add additional non-ideal effects to our ray-traces, namely diffraction and shadowing by the support structures of the gratings membranes and a finite energy resolution of the detector. Taken together, resolving power and effective area do not change much compared to our initial work, but this higher level of detail in the simulations shows that the design is workable in the presence of non-ideal effects.