Fabrication of transmission gratings for use in cosmic x-ray and XUV astronomy.

The manufacturing process of open transmission gratings with high efficiency and high line density is described. This process is developed by Dr. Johannes Heidenhain GmbH in cooperation with the Max- Planck-Institut and involves two steps, the mechanical ruling of the original master and the photochemical replication of the individual grating facets. The freestanding transmission grating is added by a regular support structure obstructing about one-third of the grating area. For application in space astronomy, gratings have been subjected to vibration and acoustic-noise tests.