Presentation details
» Glass Thermal Forming for X-ray Space Telescopes
Presentation duration: 20 minutes
Presenter: Martin Mika
We have studied the thermal forming of glass foils with the aim to develop a low-cost technology suitable for the mass-producing of thin X-ray optics shells. The parameters of the shells should meet the requirements of future large X-ray space telescopes. We have done the our experiments with commercially available 0.75 mm thin glass foils having a low micro-roughness of few 0.1 nm. Our special composite mandrels with the surface avoiding the sticking of the glass supported the foils during the slumping process. In some experiments additional force was applied on samples from the top. To find out the effects, we varied both temperature and heat-treatment time following our experiment design. We measured the shape and the surface quality (the waviness and the micro-roughness) of the micro-sheets employing the Tylor-Hobson mechanical profilometry, the optical interferometry (ZYGO), and the Atomic Force Microscopy (AFM) analysis. Knowing the response surfaces of the measured properties, we were able to determine the time-temperature area where we achieved the best surface quality with the micro-roughness below 0.3 nm. In this area the shape of the foils was dependent on the soaking time and temperature. We are able to modify the shape by controlling these two process parameters keeping the high surface quality. This way we can fabricate foils of various shapes using just one mandrel. We suppose that this approach can substantially reduce the number of expensive mandrels needed for the production of X-ray mirror shells with various shapes. We expect that besides lowering costs this technology can also significantly speed up the manufacture of X-ray telescope mirrors.
Coauthors:- Martina Landova
- Veronika Semencova
- Michaela Skulinova
- Rene Hudec
- Adolf Inneman
- Libor Sveda
- Ladislav Pina