Precise wavefront characterization of X-ray optical elements using a laboratory source

• Main Authors: Dresselhaus, J. L, Fleckenstein, H, Domaracky, M, Prasciolu, M, Ivanov, N, Carnis, J, Murray, K. T, Morgan, A. J, Chapman, H. N, Bajt, S
• Format: Journal Article
• Language: English
• Published: 27-03-2022
• Subjects: Physics - Accelerator Physics; Physics - Optics
• DOI: 10.48550/arxiv.2203.14378

Improvements in X-ray optics critically depend on the measurement of their
optical performance. The knowledge of wavefront aberrations, for example, can
be used to improve the fabrication of optical elements or to design phase
correctors to compensate for these errors. Nowadays, the characterization of
such optics is made using intense X-ray sources such as synchrotrons. However,
the limited access to these facilities can substantially slow down the
development process. Improvements in the brightness of lab-based X-ray
micro-sources in combination with the development of new metrology methods, and
in particular ptychographic X-ray speckle tracking, enable characterization of
X-ray optics in the lab with a precision and sensitivity not possible before.
Here, we present a laboratory set-up that utilizes a commercially available
X-ray source and can be used to characterize different types of X-ray optics.
The set-up is used in our laboratory on a routine basis to characterize
multilayer Laue lenses of high numerical aperture and other optical elements.
This typically includes measurements of the wavefront distortions, optimum
operating photon energy and focal length of the lens. To check the sensitivity
and accuracy of this laboratory set-up we compared the results to those
obtained at the synchrotron and saw no significant difference. To illustrate
the feedback of measurements on performance, we demonstrated the correction of
the phase errors of a particular multilayer Laue lens using a 3D printed
compound refractive phase plate.