Fast XRD2 Microdiffraction with Focusing X-Ray Microlenses

The advantages using specialty designed X-ray-polycapillary microlenses with spot sizes of 50 mu m to 200 mu m in a commercially available BRUKER D8 DISCOVER GADDS XRD2-microdiffractometer with a standard sealed X-ray tube instead of a microfocus source are shown and compared to commercially available pin hole collimators or monocapillary optics. The application of a focusing X-ray microlens instead of a monocapillary optic with similar spot size leads to an increase of the primary beam flux by a factor of approximately 10 to larger than 100 depending on the additional pinhole used at the exit of the microlens. This additional pinhole can be used to optimize the beam geometry for a better peak profile without additional changes on the setup. Therefore the use of a focusing X-ray microlens instead of a mono capillary optic reduces the measurement time by at least a factor of 10. A factor up to 200 is possible by simple changing the diameter of the exit pinhole - for the price of a wider peak profile. Due to the similar housing the focusing X-ray microlens fits in the standard collimator support enabling switching between collimators, mono-capillaries and the microlens without realignment. This is why no time consuming modification of the microdiffractometer is needed.