Studies of monolithic capillary optics for small sample crystallography

Total external reflection is used for a variety of x-ray optics. The kind discussed here employs arrays of glass capillaries to redirect x-rays. As a special application, the collimation of x-rays from a point source is discussed. Conventional x-ray collimators limit the angular spread by absorbing x-rays of a non desirable direction. Capillary optics on the other hand are able to redirect x-rays into a parallel beam. Measurements of prototype optics are shown. Theoretical and practical limitations are shown. The most important theoretical limitation can be expressed by Liouville's theorem. According to Liouville's theorem the product of angular divergence and beam size has to be kept constant. This requires the size of the output beam to be larger than the size of the source. As a result, the total output of such a system is limited by the maximum brightness that is achievable in a practical laboratory x-ray source. For the applications discussed here, small sample crystallography, this limitation is especially important.;Besides experimental results, calculations and numerical simulations are shown that demonstrate the possibilities of capillary x-ray optics. It is shown how the results of simulations help in the design of capillary x-ray optics. Some principles in the approach to design such an optics are presented. The manufacturing of an optic that meets such design specifications is still a challenge. The framework of a model to find the right manufacturing conditions is explained.;Since the performance of monolithic capillary optics depends largely on the source used, an innovative source is presented. The theoretical limit of the brilliance of electron beam impact sources is discussed.