Active micro-structured arrays for X-ray optics

The UK Smart X-Ray Optics programme is developing the techniques required to both enhance the performance of existing X-ray systems, such as X-ray telescopes, while also extending the utility of X-ray optics to a broader class of scientific investigation. The approach requires the control of the inherent aberrations of X-ray systems using an active/adaptive method. One of the technologies proposed to achieve this is micro-structured optical arrays, which use grazing incidence reflection through consecutive aligned arrays of channels. Although such arrays are similar in concept to polycapillary and microchannel plate optics, they are more flexible. Bending the arrays allows variable focal length, while flexing parts of them provides adaptive or active systems. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays. The channels may be made using deep silicon etching, which can provide appropriate aspect ratios, and flexed using piezo actuators. An exemplar application will be in the micro-probing of biological cells and tissue samples using Ti K-alpha radiation (4.5 keV) in studies related to radiation induced cancers.