Scandium/carbon filters for soft x rays

This Note deals with thin-film soft x-ray filters for operation at the wavelengths near carbon K edge (similar to4.5 nm). The filters were fabricated by magnetron sputtering deposition of thin layers of scandium (total thickness 0.1-0.2 mum) onto films of polypropylene (thickness 1.5 mum) and polyimide (thickness 0.15-0.3 mum). To protect the scandium layers from oxidation processes in the ambient environment, the filters were coated with 3 nm layers of carbon. The measured transmissions of 0.1 mum Sc/C filters are about 0.6 at the working wavelength and similar to10(-4) in the visible. The developed soft x-ray filters can be useful for soft x-ray investigations of carbon-containing materials and biological structures, utilizing radiation of laser produced plasmas and other compact x-ray sources. (C) 2003 American Institute of Physics