title: Thermal forming of glass microsheets for x-ray telescope mirror segments.
abstract: We describe a technology to mass-produce ultrathin mirror substrates for x-ray telescopes of near Wolter-I geometry. Thermal glass forming is a low-cost method to produce high-throughput, spaceborne x-ray mirrors for the 0.1-200-keV energy band. These substrates can provide the collecting area envisioned for future x-ray observatories. The glass microsheets are shaped into mirror segments at high temperature by use of a guiding mandrel, without polishing. We determine the physical properties and mechanisms that elucidate the formation process and that are crucial to improve surface quality. We develop a viscodynamic model for the glass strain as the forming proceeds to find the conditions for repeatability. Thermal forming preserves the x-ray reflectance and scattering properties of the raw glass. The imaging resolution is driven by a large wavelength figure. We discuss the sources of figure errors, and we calculate the relaxation time of surface ripples.
authors.affiliation: Center for Space Research, Massachusetts Institute of Technology, 70 Vassar Street, NE80-6091, Cambridge, Massachusetts 02139, USA. mario@alum.mit.edu
authors.forename: Mario A
authors.initials: MA
authors.lastname: Jimenez-Garate
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Hailey
authors.forename: William W
authors.initials: WW
authors.lastname: Craig
authors.forename: Finn E
authors.initials: FE
authors.lastname: Christensen