X-ray refractive planar lens with minimized absorption

Silicon refractive planar parabolic lenses with minimized absorption were fabricated by a combination of photolithography and dry-etching techniques. Focusing and spectral properties of the lenses were studied with synchrotron radiation in the energy range 8-25 keV at the European Synchrotron Radiation Facility. A focal spot of 1.8 mum with a gain of 18.5 and transmission of more then 80% was measured at 15.6 keV. The spectral characteristics were analyzed taking into account material dispersion and photon-energy attenuation in the hard x-ray range. (C) 2000 American Institute of Physics. [S0003-6951(00)00151-0].