Glass capillary x-ray optics

Elliptical monocapillary X-ray optics with focal spot size of 1 μm to 5 μm (with IfG Scientific Instruments)

With monocapillary optics smaller spot sizes down to a few micrometers can be obtained; whereas poly-capillary optics deliver spot sizes in the range of tens of micro-meters but with a higher flux density. Both capillary optical systems are applied as a substitute for pinhole collimators in local fluorescence analysis for obtaining small excitation spots on the sample. In practice they produce an intensity gain on the order of several hundreds, especially when they are used in combination with synchrotron radiation. For producing a micro-focused beam with monocapillary optics, which is useful for X-ray spectroscopy, the following aspect should be taken into account. First of all, the number of reflections inside a capillary must be minimized in order to obtain a higher transmission. Further on, the working distance, which is the distance between the end of the capillary and the sample, should not be too small in order to investigate arbitrary-shaped samples.