HfO2/Al2O3 Multilayer on Parabolic Cylinder Substrate to Monochromatize and Collimate Divergent X-Ray Beam

Abstract

A monochromatic parallel X-ray beam is essential for some X-ray applications and a multilayer on a parabolic cylinder substrate is a good choice to obtain it. In this work, an HfO2/Al2O3 multilayer with a period of 3.80 nm and a bilayer number of 60 is grown on a smooth, flat Si substrate via atomic layer deposition for a monochromatizing Cu kα 0.154 nm X-ray and the first-order peak of the X-ray reflectivity is about 45%. The multilayer-coated Si substrate is then glued on a pre-made stainless steel body with a designed parabolic cylinder profile to convert divergent X-rays from a laboratory X-ray source into a parallel beam. The surface profiles before and after gluing Si on the stainless steel body are almost the same and basically consistent with the designed one. The results show that a monochromatic parallel X-ray (0.154 nm) beam can be acquired by an HfO2/Al2O3 multilayer on a parabolic cylinder substrate and the divergence angle of the reflected beam is 0.67 mrad.