Reflective Optics for Hard X-ray Nanofocusing Applications at the ESRF

摘要

The advent of high-brightness X-ray light sources has provided the impetus for the development of focusing systems capable of yielding spatially resolved information from samples at length scales below 10 nm. Beams of such dimensions are fundamental elements in a range of instruments providing powerful analytical tools for a broad range of scientific domains including life, materials, chemical, environmental, and physical sciences. At the ESRF, particular efforts have been made towards the design and implementation of reflective optical systems capable of routine nanoprobe formation at hard X-ray wavelengths (0.1 nm and below) with resolutions in the sub-50 nm range. Often, one of the principal driving forces for the use of such systems is the capacity of reflective optics to deliver very high photon fluxes to the sample. For imaging applications at the ESRF, monochromatic photon fluxes in excess of 10~8ph/sm~2 are achievable at energies above 15keV—typically 1–2 orders of magnitude greater than accessible with current alternative technologies. Of course, such performance is not straightforward to achieve and requires considerable care both in the manufacture and implementation of the mirror systems. In this article, we describe some of the technological characteristics and limits of these optics and report on the performance of some of the systems currently in service at ESRF beamlines.