On December 28 and 29 2003,specialist group organised respectively by committee of national natural science foundation of China (alias NSFC) and bureau of science & technogy of Jiangshu province checked and accepted national key project in the Ninth-Five Year plan period funded by NSFC,namely astronomical mirror telechnogy with large aperture and high accuracy undertaken by NIAOT。It took seven years for research group of astronomical mirror telechnogy with large aperture and high accuracy to solve many technical difficult problem。They firstly developed computer-controlled active polishing technogy and fabricated polishing machine applied this technogy in China and successfully fabricated diameter 450mm active polishing disc as well as diameter 910mm paraboidal mirror with F ratio 2 and with surface accuracy of 1/30 wavelength(RMS)。Difficult problem for high spacial frequence error of surface during mirror fabrication of large aperture and deep asphericity as well as difficult problem during fabrication of large aperture tilted-axis aspherical mirror were solved。
The project group firstly developed fabrication technogy of very thiner mirror with flexible supporting and fabrication method of large aperture very thiner mirror with computer-controlled close-loop active optics technogy。Very thiner hexagonal plano mirror with 1100mm of diagonal,25mm in thickness (applied to LAMOST) was successfully fabricared。Adopting similar fabrication method as that of diameter 4-8 meter mirror,very thinner spherical mirror which is 1035mm in diameter and 26mm in thickness with with surface accuracy of 1/27 wavelength(RMS) was successfully fabricared。That indicates that difficult problem of lower rigidity during fabrication of very thinner mirror is successfully solved。
Aperture of optical/infrared astronomical telescope become much more larger than before in order to meet demands of astronomical research。Correspondingly astronomical mirror become much more larger in size,much more thinner in thickness and much more deeper in asphericity as well as much more higher in accuracy。These success on astronomical mirror telechnogy with large aperture and high accuracy in NIAOT not only stride Chinese astronomical mirror telechnogy with large aperture and high accuracy as well as deep asphericity to a new phase to become one of fewer countries mastering these technologies but also make key technology preparation for re-flourishing of Chinese astronomy in 21th century and developing astronomical telescope with much more larger aperture and much more better technology performance meanwhile creat condition to conduct international cooperation for project of Chinese optical/infrared telescope with aperture of 30-100 meter。
|