Monte Carlo-based multiphysics coupling analysis method for focusing X-ray pulsar telescope

Focusing X-ray pulsar telescope (XPT) is a typical complex space optical payload, which involves optical, mechanical, electrical and thermal disciplines. The multiphysics coupling analysis plays an important role in improving the in-orbit performance of XPT. However, the conventional multiphysics coupling analysis (MCA) methods encounter two serious problems in dealing with the XTP. One is that the energy and reflectivity information of X-ray cannot be taken into consideration, which always misunderstands the essence of XPT. The other is that the coupling data cannot be transferred automatically among different disciplines, leading to computational inefficiency and thus increase the design cost. Therefore, a new multiphysics coupling analysis method for X-ray pulsar telescope is proposed based on the Monte Carlo and the full reflective theory. The main idea, procedures and operational steps of the proposed method are addressed in detail. Firstly, this method takes both the energy and reflectivity information of X-ray into consideration simultaneously and formulate the thermal-structural coupling equation and multiphysics coupling analysis model based on the finite element analysis (FEA) method. Then, all the thermal-structural, thermal and structural analysis under different working conditions have been implemented. Secondly, the mirror deformation can be obtained using construction geometry function. Meanwhile, the polynomial function is adopted to fit the deformed mirror and meanwhile evaluate the fitting error. Thirdly, the focusing performance analysis of XPT can be evaluated by the root mean square and maximum radius of dispersion spot employing the proposed method. Finally, a six-layer nested XPT is taken as an example to verify the proposed multiphysics coupling analysis method. The simulation results show that the thermal-structural coupling deformation is bigger than others; the influencing law of deformation effect on the focusing performance has been obtained. The focusing performances of thermal-structural, thermal, structural deformations have degraded by 30.01%, 14.35% and 7.85% respectively. The RMSs of dispersion spot are 2.9143 mm, 2.6038 mm and 2.5311 mm. As a result, the validity of the proposed method is verified through comparing the simulation results and experiments, which can be employed in the reliability-based design of XPT.