Figure measurements of high-energy x-ray replicated optics

We are developing grazing incidence x-ray optics for a balloon-borne hard-x-ray telescope (HERO). The HERO mirror shells are fabricated using electroform-nickel replication off super-polished cylindrical mandrels. One of the sources for mirror resolution error is departure of the shell figure from prescription. We have modified a Vertical-scan Long Trace Profilometer (VLTP) in order to measure the figure of the inner surface of the HERO mirror shells for diameters as small as 74 mm. Metrology of the figure, the microroughness, tilt angle, the circularity for the shell mirrors and the mandrels, as well as alignment procedures are discussed. Comparison of metrology of the mandrel and the shells is presented together with results from x-ray tests.