Refractive lenses fabricated by deep SR lithography and LIGA technology for X-ray energies from 1 keV to 1 MeV

摘要

SU-8 polymer and Nickel were used to manufacture planar high aspect ratio X-ray refractive lenses by the LIGA process (Deep X-ray lithography, electroforming). The exposure of PMMA and highly sensitive SU-8 resist layers were carried out at the ANKA storage ring, Karlsruhe. Lenses of either round, segment or quasi-parabolic (kinoform) profiles have been designed, fabricated and tested at the ESRF and at the ANKA synchrotron sources with X-ray energies ranging from 12 to 55 keV. The SU-8 polymer lenses tested at ESRF showed an uniform focal line spot with FWHM of appr. 0.32 μm and gains in the range of 320. The characteristics did not alter after an absorbed dose of 2 MJ/cm3. Lenses fabricated from electroplated Ni, 320 μm thick, were tested at a photon energy of 212 keV. In this case the uniform focal line spot was about 5 μm.