Aberration effects are studied in parabolic and elliptic multilayer mirrors for hard x-rays, basing on a simple analytical approach. The interpretation of the underlying equations provides insight into fundamental limitations of the focusing properties of curved multilayers. Using realistic values for the multilayer parameters the potential impact on the broadening of the focal spot is evaluated. Within the limits of this model, systematic contributions to the spot size can be described. The work is complemented by a comparison with experimental results obtained with a W/B_4C curved multilayer mirror.
Optical Society of America
29 Sep 2008
Volume: 16 Issue: 20 Pages: 16138-16150