A New Application of Track-Etched Membranes in X-Ray and Vacuum Ultraviolet Optics

Due to their unique structure properties, track-etched membranes are widely used in scientific and engineering practice to solve specific tasks and perform certain functions. Typical examples are diffraction filters, supports for thin-film X-ray filters and collimators in solar X-ray radiometers. In this paper new non-trivial application of track-etched membranes in optical instruments exploited in vacuum is suggested. Metal-coated track-etched membranes with modified architecture of pore channels can be used as air inlet/outlet elements that block the stray optical radiation within the inner space of the instruments. The membrane consists of two arrays of opaque channels intersecting at a certain angle inside its volume. Both surfaces are coated with light-absorbing and reflective layers of aluminum, which allows background optical radiation to be suppressed by several orders of magnitude. Residual air can pass through the membrane, which reduces the mechanical load on the sensitive elements of the device during fluctuations in external pressure. The developed “black” membranes are promising for use in various X-ray optical devices, including those for space purposes.