Slits as adjustable pinholes for coherent X-ray scattering experiments

The combination of accurate translation stages with carefully polished slit blades leads to slits that have many advantages as pinholes for coherent X-ray scattering experiments. The size is adjustable and can be made as small as 0.5 mu m. Setting up is easy, while the blade thickness (1 mm tungsten) also makes the slits useful for hard X-rays. A relation between the slit-sample distance and the minimum beam size, together with the corresponding slit size, is derived. This shows that a micrometer-sized beam can be achieved with this type of slits.