Metallic powders beam system

Systems with lower concentrations of heavy metal ions can be studied by means of gra2ing-incidence XAFS spectroscopy. In grazing-incidence geometry the X-ray beam penetrates only about 10 nm into the sample. This method can be applied to study sorption on specified crystallographic planes when single crystals are used rather than powders. Incident beam angles of a fraction of E assure total (external) reflection geometry. 

XRF is used for the analysis of solid and liquid samples. For quantitative analysis the surface of the sample must be as flat as possible, as will be discussed in the applications section. There are two classes of sample holders, cassettes for bulk solid samples and cells for loose powders, small drillings, and liquids. A typical cassette for a flat bulk solid such as a polished metal disk, a pressed powder disk, a glass or polymer flat is shown in Fig. 8.26(a). The cassette is a metal cylinder, with a screw top and a circular opening or aperture, where the sample will be exposed to the X-ray beam. The maximum size for a bulk sample is shown. The sample is placed in the cassette. For a system where the sample is analyzed face down, the cassette is placed with the opening down and the... 

In laser ablation various chambers for different types of samples have been designed to analyse rod and disc-shaped samples, and powders. For example, a disc ablation chamber system accommodates a range of disc sizes including the typical metal industry standards used in spark emission spectrometry. In order to keep the distance between the ablation chamber and the plasma as short as possible, the chamber is placed directly below the ICP. Another ablation system includes a laser microprobe which consists of a ruby laser head mounted in a binocular microscope. The target area at the sample surface is selected by the microscope, then the laser beam is focused and fired. 

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