NSLS-II Seminar

In the talk I will demonstrate several algorithms to perform numerical evaluation and simulation of basic optical elements, namely planar x-ray mirrors, high resolution monochromators and crystal based focusing optics. In particular, first, I will discuss a problem of one-dimensional surface profile retrieval of x-ray mirror from grazing incidence images under coherent x-ray illumination. Three different approaches (analytical, iterative and a one based on the neural networks) to the problem will be analyzed and compared to each other. Next, a generalized solution to the problem of multi-beam dynamical x-ray diffraction from single and layered crystals will be presented. The new formalism embraces all possible diffraction geometries, including extreme cases of grazing and normal incidence and emergence. Finally, a focusing performance of cylindrically bent crystal in symmetric back diffraction geometry will be analyzed using wave-optical formalism. I will demonstrate a numerical simulation of a double-crystal setup which allows one to achieve a linear focal spot size of 2.8 nm.