Numerical dynamical analysis of two types of X-ray baffles onboard EP-FXT mirror assembly

Purpose:In order to evaluate the mechanical feasibilityof the domestic baffle made by wire electrode cutting for the mirror assembly of the Follow-upX-ray Telescope (FXT) onboard the Einstein Probe (EP) mission.
Methods:Finite element analysis was performedto compare the structural differences between the domestic bafflemade by wire electrode cutting and the eROSITA baffle made by bonding. The finite element models were verifiedby test data in advance to avoid significant deviations. Finally, the differences indynamical performances between the FXT mirror assemblies with the two baffles were investigated throughmodal analysis and frequency response analysis usingthe pre-verified models.
Results and conclusions:The results show that, from the perspective of the entiremirror assembly, their eigenfrequenciesremain similar, except for the second lateral eigenfrequency, which shifts forward by approximately24 Hz inthe mirror assembly equipped with the domestic baffle. However, for the X-ray baffles themselves, the axial and lateral eigenfrequenciesof the two baffles differ by approximately 49 Hz and 185 Hz, respectively. These eigenfrequencies are staggered, ensuringthat over-response is avoided. In terms of response amplification, the domestic baffle, compared to theeROSITA baffle, exhibits inferioraxial mechanical characteristics but superior lateral characteristics. In summary, from a mechanical perspective, the domestic baffle is feasible.