Progress in ion beam figuring of very thin slumped glass plates for lightweight x-ray telescope

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

doi:10.1117/12.2313599

28 August 2018 Progress in ion beam figuring of very thin slumped glass plates for lightweight x-ray telescope

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

Proceedings Volume 10699, Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray; 106990T (2018) https://doi.org/10.1117/12.2313599
Event: SPIE Astronomical Telescopes + Instrumentation, 2018, Austin, Texas, United States

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.

Citation Download Citation

M. Civitani, M. Ghigo, J. Holyszko, G. Vecchi, S. Basso, V. Cotroneo, C. T. De Roo, E. D. Schwartz, and P. B. Reid "Progress in ion beam figuring of very thin slumped glass plates for lightweight x-ray telescope", Proc. SPIE 10699, Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray, 106990T (28 August 2018); https://doi.org/10.1117/12.2313599

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
13 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Glasses

Ion beam finishing

Error analysis

Ion beams

Mirrors

X-ray telescopes

Data acquisition

Show All Keywords

Keywords/Phrases

Search In:

Publication Years