Progress in ion beam figuring of very thin glass plates for lightweight X-ray telescopes

M. Civitani; M. Ghigo; J. Holyszko; G. Vecchi; S. Basso; V. Cotroneo; C. T. DeRoo; E. D. Schwartz; P. B. Reid

doi:10.1117/12.2313599

Back

Conference proceeding

Progress in ion beam figuring of very thin glass plates for lightweight X-ray telescopes

M. Civitani, M. Ghigo, J. Holyszko, G. Vecchi, S. Basso, V. Cotroneo, C. T. DeRoo, E. D. Schwartz and P. B. Reid

SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY, Vol.10699

Proceedings of SPIE

01/01/2018

DOI: 10.1117/12.2313599

View Online

Abstract

The combination of the hot slumping and the Ion Beam Figuring (IBF) technologies can be a very competitive solution for the realization of x-ray optics with excellent imaging capabilities and high throughput. While very thin mirrors segments can be realized by slumping with residual figure errors below few hundreds of nanometres, a non-contact and deterministic process (dependent on dwell time), like IBF, is a very effective post facto correction, as it avoids all the problems due to the handling and the supporting system. In the last years, the two processes were proven compatible with very thin sheet of Eagle XG glasses (0.4 mm thickness). Nevertheless, the fast convergence of the process is a key factor to limit the cost of the mirror plate production. A deeper characterization of removal function stability showed that its repeatability between each run has to be improved for a real enhancement of the process convergence factor. A new algorithm based on de-convolution has been implemented and tested, with important advantages in terms of calculation speed, minimum material removal and optimization possibilities. By analysing the metrological data of test slumped glasses, we showed how the IBF is effective in the correction of figure errors on scales above 8 - 10 mm. An overall figuring time of few hours is required with surface error around 100 nm rms. Thanks to the thickness measurement data, which are performed in transmission mode with an interferometric set-up, we demonstrated that it is possible to disentangle the effective amount of the material removed and the deformations introduced during the process.

Astronomy & Astrophysics

Optics

Physical Sciences

Science & Technology

Details

Title: Subtitle: Progress in ion beam figuring of very thin glass plates for lightweight X-ray telescopes
Creators: M. Civitani - INAF, Brera Astron Observ, Via E Bianchi 46, I-23807 Merate, LC, Italy
M. Ghigo - INAF, Brera Astron Observ, Via E Bianchi 46, I-23807 Merate, LC, Italy
J. Holyszko - INAF, Brera Astron Observ, Via E Bianchi 46, I-23807 Merate, LC, Italy
G. Vecchi - INAF, Brera Astron Observ, Via E Bianchi 46, I-23807 Merate, LC, Italy
S. Basso - INAF, Brera Astron Observ, Via E Bianchi 46, I-23807 Merate, LC, Italy
V. Cotroneo - Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
C. T. DeRoo - Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
E. D. Schwartz - Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
P. B. Reid - Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
Contributors: JWA DenHerder (Editor)
S Nikzad (Editor)
K Nakazawa (Editor)
Resource Type: Conference proceeding
Publication Details: SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY, Vol.10699
Publisher: Spie-Int Soc Optical Engineering
Series: Proceedings of SPIE
DOI: 10.1117/12.2313599
ISSN: 0277-786X
eISSN: 1996-756X
Number of pages: 13
Language: English
Date published: 01/01/2018
Academic Unit: Physics and Astronomy; University College Courses
Record Identifier: 9984442013802771

Metrics

4 Record Views