High energy X-ray nanofocusing by silicon planar lenses

Abstract

Optimizing the lens design and improving the technological process, we manufactured X-ray planar compound refractive lenses with vertical sidewalls up to 70 microns deep. The lens surface roughness in the order of 20 nm was attained. The minimal thickness of the material between two individual lenses of 2 μm was realized. The optical tests of the new planar lenses were performed at the ESRF BM05 and ID15 beamlines. The technological breakthrough allows reaching the nanometer focusing. The resolution below 200 nm was measured in the energy region of 15–80 keV. The best resolution of 150 nm was demonstrated at 50 keV X-rays.