Design and optimization of 1.2-m primary mirror supporting systems

The 1.2-m primary mirror supporting systems are composed of axial support system with whiffletree structure and lateral support system with 6 tangent links. With the simulation based on the finite element analysis (FEA), the 18 points positions of the axial support are determined and the bottom chamber structure of the primary mirror is improved. In order to reduce the mirror surface deformation, the assembly stress on the primary mirror is reduced by optimizing the lateral support structure. The analysis results demonstrated that the root-mean-square (RMS) of the surface deformation is 10.9nm when the primary mirror points vertically. Meanwhile the RMS of the surface deformation is 10.3nm when the primary mirror points horizontally.