The mid and low-spatial frequency error control technology research during the process with ion-beam figuring in large aperture standard mirror
Abstract
By the ion-beam figuring machine IBF600, a 630 mm aperture fused silica flat standard mirror was polished up to surface PV value 38.9 nm and RMS 6.556 nm in low frequency error, during the same time ,the mirror's mid-spatial frequency(spatial frequency band 2.5 mm 33 mm) wavefront RMS error converged to 1.502 nm from initial value 2.022 nm.During the process, two removal functions were used in the simulation after parameter optimization. According to the residual error map, we choose the appropriate removal function and calculate the dwell time, finally we successfully attained the optical acquirements of the standard mirror in both low and middle frequency error, this high middle frequency.
- Publication:
-
Second Symposium on Novel Technology of X-Ray Imaging
- Pub Date:
- May 2019
- DOI:
- 10.1117/12.2524634
- Bibcode:
- 2019SPIE11068E..1TZ