An optimized optical system with 1.65m wide-field corrector for the 6.5m high-performance MUltiplexed Survey Telescope

• Yifan Zhang, Qi Bian, Liquan Guo, Stephen Schectman, Zhongtian Tian, Jinlong Huang, Chen Xu, Zheng Cai, Song Huang, Lu Lu, Yamin Zheng, Shude Mao, and Lei Huang
• received 02/20/2024; accepted 04/28/2024; posted 04/29/2024; Doc. ID 521907
• Abstract: The development of modern large-scale spectroscopicsurvey telescopes responds to the urgent demand forspectral information in astronomical research. TsinghuaUniversity has previously proposed a 6.5m MUltiplexedSurvey Telescope composed of a Ritchey-Chretien configuration and a 1.8m multi-element wide-field corrector, achieving excellent performance and world-leadingsurvey efficiency. However, an optimized 1.65m multielement corrector with five lenses is proposed to overcome the constraints on glass uniformity and verificationin fabrication of the previous corrector design. It maintains outstanding image quality with the 80% enclosedenergy diameter not more than 0.559 arcsec within 3°FoV over at up to 55° zenith angle. The optimized optical system does not revise the working mode of theADC and the curvature of the primary mirror, while ensuring the reasonability and accuracy of manufacturingof large corrector elements. It provides a more feasible reference optical design for the MUltiplexed SurveyTelescope in subsequent iterations and communicationswith manufacturers.