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Nowadays XAFS is one of the fundamental research tools to study structure and electronic states from noncrystallinematerials. We have to remind that we handle faint XAFS oscillation on fairly high background signal inthe analysis of XAFS spectra. Thus we have to pay attention on the beamline alignment, sample preparation anddetection systems.
XAFS signal is discussed from the view point of signal-to-noise ratio limited by the available photon flux. Thediscussion indicates the S/N ratio of XAFS in transmission mode is not limited by the available photon flux in general.The purity of the X-ray beam, uniform sample preparation are more important than the photon flux. Detection systemis also an important part to obtain reliable XAFS spectrum. Operation of ionization chambers and Ge detectors will beexplained. Fluorescent XAFS is a sensitive method to study dilute species but is not the superset of the transmissionmeasurement. The limitation of the fluorescent XAFS will be briefly explained.
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