Null corrector forΦ1200 F/1.5 paraboloidal mirror must compensate 0.087mm surface departure from the best fitting sphere
and realize the surface error less than 0.033λ(RMS). The design
error analysis
manufacturing
certification and final application of the corrector are introduced in detail. The certification by computer-generated hologram (CGH) in advance shows that the shape and conic errors produced by corrector are 0.012λ(RMS)and 0.0064%
and the final null testing results
surface and conic error
of primary mirror are 0.027λ(RMS)and 0.0306%
all these are consistent with the tolerance analysis. The results indicate the design ,tolerance analysis and quality of corrector are rational and reliable
and this has laid solid foundation for the null test of larger fast primary mirror.