Abstract: It is a huge technical &engineering challenge to realize the precise assembly of thousands large optical units in China’s inertial confinement fusion system SG-III with 48 high power laser beams. Using the reflecting mirror unit as an example, a comprehensive methodology with an integration of theoretical modeling, numerical simulation and experimental study, is proposed. Theoretical modeling methods of tolerance stack-up and surface deflection are presented. Then using some powerful engineering software, ANSYS and 3DCS, both three dimensional assembly errors during mounting optics and surface deformation under fastening forces are analyzed and predicated. Finally, in a real optics assembly building, experiments are undertaken to verify the proposed methodology, and the results also solidify the methodology’s feasibility. This method is promising to apply into more optics assembly studies in the inertial confinement fusion engineering.

Key words: modeling and simulation, optical unit, precision assembly, surface deflection, tolerance stackup