CONCENTRATION OF SYNCHROTRON BEAMS BY MEANS OF MONOLITHIC POLYCAPILLARY X-RAY OPTICS

Capillary optics are valuable tools for concentrating synchrotron radi ation [D.J. Tiel, A.E. Stern, D.H. Bilderback and A. Lewis, Physica B 158 (1989) 314]. Single tapered capillaries are used at several facili ties. However, most of these optics collect only over a small area. Th is can be overcome by using larger capillary structures. Polycapillary optics can deflect X-rays by larger angles than other X-ray optics th at use only one or two reflections. Conventional X-ray optics that ach ieve similar deflections are much more energy selective than capillari es. Therefore, capillaries can achieve very short focal distances for a wide range of energies. The measurements shown here represent first tests performed with polycapillaries with large collection area. The p erformance with respect to transmission efficiency and spot size was e valuated for a set of four very different prototypes. It is shown that for these prototypes a significant gain may be achieved if a spot siz e of the order of 0.1 mm is required. Further, some characteristics of the different optics are discussed.