Two-Step Kirkpatrick–Baez System: Compact Optics for X-ray Microfocusing

A design concept is presented for a compact X-ray microfocusing system, which consists of two sets of Kirkpatrick–Baez (K–B) optics and intermediate slits. The proposed optics enables us to achieve a high demagnification factor, while the total length of the optics is relatively small. Ray-tracing simulations demonstrate that a spot size comparable to that of a conventional K–B optics is achieved using the two-step K–B microfocusing system with much shorter optics, keeping the same working distance. Preliminary results from a prototype system are also reported. A 3.3 µm spot was obtained after a proper alignment, which agrees well with the expected spot size.