Planar parabolic lenses for focusing high-energy x-rays

Microelectronics technology involving photolithography and highly anisotropic plasma etching techniques was applied to fabricate planar parabolic refractive lenses. A set of Si planar parabolic lenses with apertures from 0.5 to 1.8 mm and 200 microns deep has been fabricated especially for high energy X-rays (E > 50 keV). Focusing properties in terms of the spot size and the efficiency in the energy range from 50 to 100 keV have been studied at the ESRF ID15 beamline. Linear focusing by single lens and by two-lens system as well as two-dimensional focusing by two lenses in cross geometry has been realized. Features of refractive collimator based on a set of planar lenses have been investigated and a technique for evaluation of the beam divergence in a micro radian range has been proposed. Future applications of proposed planar lenses are discussed.