Efficient sub 100nm focusing of hard x rays

Abstract

An x-ray beam with energy of 20.5keV has been efficiently focused down to a spot size as small as 90nm×90nm by a Kirkpatrick–Baez reflecting mirrors device. The first mirror, coated with a graded multilayer, plays both the role of vertical focusing device and monochromator, resulting in a very high flux (2×1011photons∕s) and medium monochromaticity (ΔE∕E∼10−2). Evaluation of the error contributions shows that the vertical focus is presently limited by the mirror figure errors, while the horizontal focus is limited by the horizontal extension of the x-ray source. With a gain in excess of a few million, this device opens up new possibilities in trace element nanoanalysis and fast projection microscopy.

Semi-transparent central stop in high-resolution X-ray ptychography using Kirkpatrick–Baez focusing

“…First results using divergent beams have been reported, including nano-focusing refractive X-ray lenses (Schropp et al, 2010(Schropp et al, , 2012Hö nig et al, 2011), Fresnel zone plates (Vila-Comamala et al, 2011;Huang et al, 2012;Wilke et al, 2012) and Kirkpatrick-Baez (KB) mirrors Takahashi et al, 2011Takahashi et al, , 2013Huang et al, 2012;Giewekemeyer et al, 2013). KB mirrors are attractive focusing devices due to their high efficiency at sub-100 nm focusing while providing long working distances of hundreds of millimetres (Hignette et al, 2005;Matsuyama et al, 2006;Mimura et al, 2007Mimura et al, , 2010Mimura et al, , 2011. However, efficient KB mirror optics in combination with the high coherent flux provided by modern synchrotrons such as PETRA III result in data that cannot be processed by current photon-counting detector technologies.…”

Hard x-ray scanning microscopy with coherent radiation: Beyond the resolution of conventional x-ray microscopes

“…3 In conventional x-ray microscopy the spatial resolution is currently limited to a few 10 nm, 3 mainly due to aberrations and the limited numerical aperture of today's x-ray optics. [4][5][6][7] By combining scanning microscopy with coherent x-ray diffraction imaging this limit can be overcome. In recent years, scanning coherent diffraction microscopy, also known as ptychography, has been rediscovered 8 and introduced into the field of x-ray imaging.…”

Correcting lateral chromatic aberrations in non-monochromatic X-ray microscopy

“…4 More recently, microscopy based on Kirkpatrick-Baez mirrors was performed, showing negligible chromatic aberration in the 8-11 keV range, making the technique suitable for spectromicroscopy. 5 Focusing X-ray optics is commonly based either on curved crystal mirrors, [6][7][8] Fresnel zone plates, 9 or compound refractive lenses (CRLs). 10 Using CRLs for microscopy has the advantage of high efficiency, and scalability to higher energy x-rays, 11 which is beneficial when sample transmission is a limiting factor.…”