Future X-ray observatory missions, such as IXO or Gen-X, require grazing incidence optics of large collecting area in
combination with a very good angular resolution. Wolter type I X-ray telescopes made of slumped glass segments could
be a possible alternative to silicon pore optics. To achieve these requirements we develop slumping methods for high
accuracy segments by experimental means. In particular, we follow the approach of indirect slumping and aim to
produce parabola and hyperbola in one piece. In order to avoid internal stress in the glass segments the thermal
expansion coefficient of the glass should closely match the thermal expansion of the mould material. Currently we focus
on a combination of the alloy KOVAR for the mould and D263 for the glass; additionally a platinum-coated silica as
mould material is studied. We investigate the behaviour of both materials during slumping in order to obtain the ideal
environment for the slumping process. Additionally we report on the design of different metrology methods to measure
the figure and thickness variations of the glass segments in visual light, e.g. interference, and on bearings used for shape
measurements and integration.
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