Titanium Alloy Strong Back for IXO Mirror Segments

A titanium-alloy mirror-holding fixture called a strong back allows the temporary and permanent bonding of a 50° D263 glass x-ray mirror (IXO here stands for International X-ray Observatory). The strong back is used to hold and position a mirror segment so that mounting tabs may be bonded to the mirror with ultra-low distortion of the optical surface. Ti-15%Mo alloy was the material of choice for the strong back and tabs because the coefficient of thermal expansion closely matches that of the D263 glass and the material is relatively easy to machine.